Debug.setNonUserCodeExceptions - Archive of obsolete content
the debug.setnonusercodeexceptions property determines whether any try-catch blocks in this scope are to be treated by the debugger as user-unhandled. exceptions can be classified as thrown, user-unhandled or unhandled. syntax debug.setnonusercodeexceptions [= bool]; remarks if this property is set to true within a given scope, the debugger can then choose whether to take some specified action on exceptions thrown inside that scope: for instance, if the developer wishes to break on user-unhandled exceptions. setting this property to false is the same as never having set the property. for more information on debugging, see the active script debugging overview. example the following code shows how to set this property. ...
... } })(); requirements supported in the following document modes: internet explorer 10 standards and internet explorer 11 standards. also supported in store apps (windows 8 and windows phone 8.1). ...
... } })(); requirements supported in the following document modes: internet explorer 10 standards and internet explorer 11 standards. also supported in store apps (windows 8 and windows phone 8.1). ...

JS_ReportPendingException
forward the current pending exception in a given jscontext to the current jserrorreporter callback. syntax bool js_reportpendingexception(jscontext *cx); name type description cx jscontext * the context in which the exception was thrown. requires request. in a js_threadsafe build, the caller must be in a request on this jscontext. description if an exception is pending in the context cx, js_reportpendingexception converts the exception to a string and reports it to the current error reporter. on success, it clears the exception as though by calling js_clearpendingexception and returns true. if no exception is pending, or if a second error occurs while trying to report the first one, it returns false. ...
...if an exception is pending in the context cx, js_reportpendingexception converts the exception to a string and reports it to the current error reporter. on success, it clears the exception as though by calling js_clearpendingexception and returns true. if no exception is pending, or if a second error occurs while trying to report the first one, it returns false. this function can be used to catch exceptions thrown from scripts and send them to the error reporter to be logged or ignored. note that certain jsapi functions automatically do this for uncaught exceptions; see "automatic handling of uncaught exceptions" in the jsapi user guide. ...
...econd error occurs while trying to report the first one, it returns false. this function can be used to catch exceptions thrown from scripts and send them to the error reporter to be logged or ignored. ...

nsIException
inherits from: nsisupports last changed in gecko 1.7 method overview string tostring(); attributes attribute type description columnnumber pruint32 valid column numbers begin at 0. there is no unambiguous indicator for unknown. read only. data nsisupports arbitary data for the implementation. read only. filename string filename location. this is the location that caused the error, which may or may not be a source file location. for example, standard language errors would generally have the same location as their top stack entry. file parsers may put the location of the file they were parsing. ...
...lementation. read only. filename string filename location. this is the location that caused the error, which may or may not be a source file location. for example, standard language errors would generally have the same location as their top stack entry. file parsers may put the location of the file they were parsing. null indicates "no data" read only. inner nsiexception an inner exception that triggered this, if available. read only. linenumber pruint32 valid line numbers begin at '1'. '0' indicates unknown. read only. location nsistackframe a stack trace, if available. read only. message string a custom message set by the thrower. [binaryname(messagemoz)] read only. name string the name of the error...
...bers begin at '1'. '0' indicates unknown. read only. location nsistackframe a stack trace, if available. read only. message string a custom message set by the thrower. [binaryname(messagemoz)] read only. name string the name of the error code (a string representation of result) read only. result nsresult the nsresult associated with this exception. read only. methods tostring() a generic formatter - make it suitable to print, etc. string tostring(); parameters none. return value a string suitable for output. ...

DOMException.name - Web APIs
specifications specification status comment web idlthe definition of 'name' in that specification. ...
... specifications specification status comment web idlthe definition of 'name' in that specification. ...
... specifications specification status comment web idlthe definition of 'name' in that specification. ...

Exception - MDN Web Docs Glossary: Definitions of Web-related terms
an exception is a condition that interrupts normal code execution. in javascript syntax errors are a very common source of exceptions. ...
... an exception is a condition that interrupts normal code execution. in javascript syntax errors are a very common source of exceptions. ...

JS_ErrorFromException
get or create jserrorreport from an exception object. syntax jserrorreport * js_errorfromexception(jscontext *cx, js::handleobject obj); name type description cx jscontext * pointer to a js context whose errors should be reported via your function. other contexts in the same runtime can have their own error reporting functions. obj js::handleobject an exception object. description if obj is an exception object, the exception will have (or be able to lazily create) an error report struct, and js_errorfromexception will return the address of that struct. otherwise, it returns nullptr. the lifetime of the error report struct that might be returned is the same as the lifetime of the exception object. see also mxr id search for js_errorfrom...
...eption object. description if obj is an exception object, the exception will have (or be able to lazily create) an error report struct, and js_errorfromexception will return the address of that struct. otherwise, it returns nullptr. the lifetime of the error report struct that might be returned is the same as the lifetime of the exception object. ...

DOMException() - Web APIs
the domexception() constructor returns a domexception object with a specified message and name. syntax var domexception = new domexception(); var domexception = new domexception(message); var domexception = new domexception(message, name); parameters message optional a description of the exception. if not present, the empty string '' is used. name optional returns a domstring that contains one of the strings associated with an error constant. return value domexception a newly created domexception object. example tbd specifications specification status comment web idlthe definition of 'domexception()' in that specification. candidate recommendation adds the constructor for the domexception class. browser compatibility the compatibility t...
...n class. browser compatibility the compatibility table on this page is generated from structured data. if you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. ...

FileException - Web APIs
basic concepts synchronous apis do not have error callbacks, which makes it difficult to catch errors. the added complexity of using webworkers with this api makes debugging even more challenging. to simplify things a bit, wrap your worker code in a try/catch. when errors occur, forward them to the main app using postmessage() as in the following: function onerror(e) { postmessage('error:' + e.tostring()); } try { //error is thrown if "log.txt" already exists. ...
...eentry. browser compatibility the compatibility table on this page is generated from structured data. if you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. ...

XPathException - Web APIs
constants constant value description invalid_expression_err 51 if the expression has a syntax error or otherwise is not a legal expression according to the rules of the specific xpathevaluator or contains specialized extension functions or variables not supported by this implementation. type_err 52 if the expression cannot be converted to return the specified type. ...
... recommendation initial definition ...

NPN_SetException - Archive of obsolete content
« gecko plugin api reference « scripting plugins summary a plugin can call this function to indicate that a call to one of the plugin's npobjects generated an error. syntax #include <npruntime.h> void npn_setexception(npobject *npobj, const nputf8 *message); parameters the function has the following parameters: <tt>npobj</tt> the object on which the exception occurred. <tt>message</tt> a utf-8 string describing the error that occurred. returns nothing. ...

nsIDOMFileException
last changed in gecko 1.9 (firefox 3) attributes attribute type description code unsigned short the error code describing the error condition that took place; see the constants list for details. constants constant value description not_found_err 0 the specified file wasn't found. not_readable_err 1 the specified file wasn't readable. ...

nsIDOMXPathException
inherits from: nsisupports last changed in gecko 1.7 attributes attribute type description code unsigned short the error code; see error codes for details. constants error codes constant value description invalid_expression_err 51 an invalid xpath expression was used. type_err 52 an attempt was made to reference an unavailable type. ...

nsIXSLTException
content/xslt/public/nsixsltexception.idlscriptable please add a summary to this article. inherits from: nsiexception last changed in gecko 1.7 attributes attribute type description sourcenode nsidomnode the context node, may be null. read only. stylenode nsidomnode the node in the stylesheet that triggered the exception. read only. ...

Breaking on exceptions - Firefox Developer Tools
to instruct the debugger to pause on an exception, tick these checkboxes in the breakpoints list: pause on exceptions pause on caught exceptions when an exception occurs, the line where it occurs is highlighted in the source pane, with a squiggly red line under the problematic code. a tooltip describes the exception. starting in firefox 80, a disclosure triangle within the tooltip reveals a stack trace. ...

DOMException.code - Web APIs
specifications specification status comment web idlthe definition of 'code' in that specification. candidate recommendation browser compatibility the compatibility table on this page is generated from structured data. if you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. ...

DOMException.message - Web APIs
specifications specification status comment web idlthe definition of 'message' in that specification. candidate recommendation browser compatibility the compatibility table on this page is generated from structured data. if you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. ...

XPathException.code - Web APIs
the code read-only property of the xpathexception interface returns a short that contains one of the error code constants. syntax var exceptioncode = exception.code; value a short number representing the error code. specifications specification status comment document object model (dom) level 3 xpath specificationthe definition of 'xpathexception' in that specification. recommendation initial definition ...

nsIXPConnect
, in nsiclassinfo aclassinfo, in nsixpconnectjsobjectholder aprototype); void setdebugmodewhenpossible(in prbool mode); native code only! void setdefaultsecuritymanager(in nsixpcsecuritymanager amanager, in pruint16 flags); nsixpcfunctionthistranslator setfunctionthistranslator(in nsiidref aiid, in nsixpcfunctionthistranslator atranslator); void setreportalljsexceptions(in boolean reportalljsexceptions); void setsafejscontextforcurrentthread(in jscontextptr cx); void setsecuritymanagerforjscontext(in jscontextptr ajscontext, in nsixpcsecuritymanager amanager, in pruint16 flags); void syncjscontexts(); void updatexows(in jscontextptr ajscontext, in nsixpconnectwrappednative aobject, in pruint32 away); native code only! obsol...
...objectholder aholder); attributes attribute type description collectgarbageonmainthreadonly prbool obsolete since gecko 1.9 currentjsstack nsistackframe read only. currentnativecallcontext nsaxpcnativecallcontextptr read only. deferreleasesuntilaftergarbagecollection prbool obsolete since gecko 1.9 pendingexception nsiexception constants constant value description init_js_standard_classes 1 << 0 flag_system_global_object 1 << 1 omit_components_object 1 << 2 xpc_xow_clearscope 1 tells updatexows() to clear the scope of all of the xows it finds. obsolete since gecko 2.0 methods native code only!addjsholder ...
... xpc_xow_clearscope 1 tells updatexows() to clear the scope of all of the xows it finds. obsolete since gecko 2.0 methods native code only!addjsholder root js objects held by aholder. void addjsholder( in voidptr aholder, in nsscriptobjecttracerptr atracer ); parameters aholder the object that hold the js objects that should be rooted. atracer missing description exceptions thrown missing exception missing description clearallwrappednativesecuritypolicies() void clearallwrappednativesecuritypolicies(); parameters none. exceptions thrown missing exception missing description native code only!createsandbox create a sandbox for evaluating code in isolation using evalinsandboxobject(). nsixpconnectjsobjectholder createsandbox( in jscontextptr cx,...
...And 54 more matches

imgIContainer
2.0 void startanimation(); obsolete since gecko 2.0 void stopanimation(); obsolete since gecko 2.0 void unlockimage(); attributes attribute type description animated boolean whether this image is animated. you can only be guaranteed that querying this will not throw if status_decode_complete is set on the imgirequest. read only. exceptions thrown ns_error_not_available if the animated state cannot be determined. animationmode unsigned short currentframe gfxasurface get a surface for the current frame. this may be a platform-native, optimized frame, so you cannot inspect its pixel data. read only. native code only! obsolete since gecko 2.0 currentframein...
...nsigned long the index of the current frame that would be drawn if the image was to be drawn now. read only. obsolete since gecko 2.0 currentframeisopaque boolean whether the current frame is opaque; that is, needs the background painted behind it. read only. height print32 the height of the container rectangle. in the case of any error, zero is returned, and an exception will be thrown. read only. loopcount long number of times to loop the image. note: -1 means forever. obsolete since gecko 2.0 numframes unsigned long the total number of frames in this image. read only. obsolete since gecko 2.0 preferredalphachannelformat gfx_format read only. obsolete since gecko 1.9.2 type unsigned short the t...
...long the total number of frames in this image. read only. obsolete since gecko 2.0 preferredalphachannelformat gfx_format read only. obsolete since gecko 1.9.2 type unsigned short the type of this image (one of the type_* values above). read only. width print32 the width of the container rectangle. in the case of any error, zero is returned, and an exception will be thrown. read only. constants constant value description type_raster 0 enumerated values for the 'type' attribute (below). type_vector 1 flag_none 0x0 flags for imgicontainer operations. meanings: flag_none: lack of flags. flag_sync_decode: forces synchronous/non-progressive decode of all available data be...
...And 49 more matches

nsIMsgIncomingServer
server. usesecauth boolean valid boolean constants constant value description defaultsocket 0 trytls 1 alwaysusetls 2 usessl 3 keepdups 0 deletedups 1 movedupstotrash 2 markdupsread 3 methods clearallvalues() this is really dangerous. this destroys all pref values do not call this unless you know what you're doing! void clearallvalues(); parameters none. ...
...an valid boolean constants constant value description defaultsocket 0 trytls 1 alwaysusetls 2 usessl 3 keepdups 0 deletedups 1 movedupstotrash 2 markdupsread 3 methods clearallvalues() this is really dangerous. this destroys all pref values do not call this unless you know what you're doing! void clearallvalues(); parameters none. ...
...at you're doing! void clearallvalues(); parameters none. exceptions thrown missing exception missing description cleartemporaryreturnreceiptsfilter() if sent folder pref is changed we need to clear the temporary return receipt filter so that the new return receipt filter can be recreated (by configuretemporaryreturnreceiptsfilter()). void cleartemporaryreturnreceiptsfilter(); parameters none. exceptions thrown missing exception missing description closecachedconnections() void closecachedconnections(); parameters none. exceptions thrown missing exception missing description configuretemporaryfilters() for mail, this configures both the mdn filter, and the server-side spam filter filters, if needed. if we have set up to filter return receipts into our sent folder, this utility method create...
...And 34 more matches

WebIDL bindings
implemented by an object with a property whose name matches the operation, the object itself is always used as this. if the interface is not a single-operation interface, it just exposes a single method for every idl method/getter/setter. the signatures of the methods correspond to the signatures for throwing idl methods/getters/setters with an additional trailing "mozilla::dom::callbackobject::exceptionhandling aexceptionhandling" argument, defaulting to ereportexceptions. if areportexceptions is set to ereportexceptions, the methods will report js exceptions before returning. if areportexceptions is set to erethrowexceptions, js exceptions will be stashed in the errorresult and will be reported when the stack unwinds to wherever the errorresult was set up. for example, this webidl: callback i...
... short somemethod(domstring somestring); }; callback interface myothercallback { // single-operation interface short dosomething(node somenode); }; interface myinterface { attribute mycallback foo; attribute mycallback? ...
...(domstring somestring); }; callback interface myothercallback { // single-operation interface short dosomething(node somenode); }; interface myinterface { attribute mycallback foo; attribute mycallback? ...
...And 31 more matches

Index - Web APIs
lerate, which indicates the sample rate to use for the new context. 140 audiodestinationnode api, audiodestinationnode, interface, reference, web audio api audiodestinationnode has no output (as it is the output, no more audionode can be linked after it in the audio graph) and one input. the number of channels in the input must be between 0 and the maxchannelcount value or an exception is raised. 141 audiodestinationnode.maxchannelcount api, audiodestinationnode, property, reference, référence(2), web audio api, maxchannelcount an unsigned long. 142 audiolistener api, audiolistener, interface, reference, référence(2), web audio api the audiolistener interface represents the position and orientation of the unique person listening to ...
...07 audioworkletnode.onprocessorerror api, audio, audioworkletnode, audioworkletprocessor, event handler, property, reference, web audio api, onprocessorerror the onprocessorerror property of the audioworkletnode interface defines an event handler function to be called when the processorerror event fires. this occurs when the underlying audioworkletprocessor behind the node throws an exception in its constructor, the process method, or any user-defined class method. 208 audioworkletnode.parameters api, audio, audioparam, audioworkletnode, experimental, property, reference, web audio api the read-only parameters property of the audioworkletnode interface returns the associated audioparammap — that is, a map-like collection of audioparam objects. they are instantia...
...sprimitivevalue interface derives from the cssvalue interface and represents the current computed value of a css property. 440 cssprimitivevalue.getcountervalue() api, cssprimitivevalue, method, needsexample, getcountervalue the getcountervalue() method of the cssprimitivevalue interface is used to get the counter value. if this css value doesn't contain a counter value, a domexception is raised. modification to the corresponding style property can be achieved using the counter interface. 441 cssprimitivevalue.getfloatvalue() api, cssprimitivevalue, method, getfloatvalue the getfloatvalue() method of the cssprimitivevalue interface is used to get a float value in a specified unit. if this css value doesn't contain a float value or can't be converted into th...
...And 23 more matches

Index
js::add*root jsapi reference, needscontent, obsolete, reference, référence(2), spidermonkey these functions are obsoleted, use js::persistentrooted instead. 23 js::autoidarray jsapi reference, reference, référence(2), spidermonkey js::autoidarray takes the ownership of jsidarray, and frees it in destructor by calling js_destroyidarray. 24 js::autosaveexceptionstate jsapi reference, reference, référence(2), spidermonkey js::autosaveexceptionstate saves and later restores the current exception state of a given jscontext. 25 js::autovaluearray jsapi reference, reference, référence(2), spidermonkey js::autovaluearray<n> holds a rooted array of js::value. this is typically used for local variables being passed to function ...
...lloc}cangc, the js engine may call the large-allocation- failure callback, if set, to allow the embedding to flush caches, possibly perform shrinking gcs, etc. to make some room. the allocation will then be retried (and may still fail.) 68 js::setoutofmemorycallback jsapi reference, reference, référence(2), spidermonkey unlike the error reporter, which is only called if the exception for an oom bubbles up and is not caught, the js::outofmemorycallback is called immediately at the oom site to allow the embedding to capture the current state of heap allocation before anything is freed. if the large-allocation-failure callback is called at all (not all allocation sites call the large-allocation-failure callback on failure), it is called before the out-of-memory callback; the out...
...e ownership of string and frees it in destructor. 87 jsautocompartment jsapi reference, spidermonkey no summary! 88 jsbool jsapi reference, obsolete, spidermonkey no summary! 89 jscheckaccessop jsapi reference, obsolete, reference, référence(2), spidermonkey check whether obj[id] may be accessed per mode, returning js_false on error/exception, js_true on success with obj[id]'s stored value in *vp. as for jspropertyop, id is either a string or an int jsval. 90 jsclass jsapi reference, spidermonkey use jsclass to define a custom class of javascript objects. a jsclass has a name, flags, and several callback functions for advanced customization of object behavior. 91 jsclass.call jsapi reference, spider...
...And 20 more matches

nsIDBFolderInfo
rvalue sorttype nsmsgviewsorttypevalue version unsigned long viewflags nsmsgviewflagstypevalue viewtype nsmsgviewtypevalue methods andflags() long andflags( in long flags ); parameters flags missing description return value missing description exceptions thrown missing exception missing description changeexpungedbytes() void changeexpungedbytes( in long delta ); parameters delta missing description exceptions thrown missing exception missing description changenummessages() void changenummessages( in long delta ); parameters delta missing description exceptions thrown m...
...n missing exception missing description changeexpungedbytes() void changeexpungedbytes( in long delta ); parameters delta missing description exceptions thrown missing exception missing description changenummessages() void changenummessages( in long delta ); parameters delta missing description exceptions thrown missing exception missing description changenumunreadmessages() void changenumunreadmessages( in long delta ); parameters delta missing description exceptions thrown missing exception missing description getbooleanproperty() boolean getbooleanproperty( in string propertyname, in boolean defaultvalue ); parameters propertyname missing description ...
...messages( in long delta ); parameters delta missing description exceptions thrown missing exception missing description getbooleanproperty() boolean getbooleanproperty( in string propertyname, in boolean defaultvalue ); parameters propertyname missing description defaultvalue missing description return value missing description exceptions thrown missing exception missing description getcharacterset() void getcharacterset( out acstring charset, out boolean overriden ); parameters charset missing description overriden missing description exceptions thrown missing exception missing description getcharactersetoverride() obsolete since gecko 1.8 (firef...
...And 20 more matches

LiveConnect Overview - Archive of obsolete content
argument of type char. for example, you can pass the string "h" to the character constructor as follows: var c = new java.lang.character("h"); in javascript 1.3 and earlier, you must pass such methods an integer which corresponds to the unicode value of the character. for example, the following code also assigns the value "h" to the variable c: var c = new java.lang.character(72); handling java exceptions in javascript when java code fails at run time, it throws an exception. if your javascript code accesses a java data member or method and fails, the java exception is passed on to javascript for you to handle. beginning with javascript 1.4, you can catch this exception in a try...catch statement. (although this functionality (along with some others) had been broken in gecko 1.9 (see bug 391642) ...
...he mozilla-specific liveconnect code had not been maintained inside mozilla, with java 6 update 11 and 12 building support for reliance on mozilla's implementation of the generic (and cross-browser) npapi plugin code, this has again been fixed.) for example, suppose you are using the java forname method to assign the name of a java class to a variable called theclass. ...
...mplementation of the generic (and cross-browser) npapi plugin code, this has again been fixed.) for example, suppose you are using the java forname method to assign the name of a java class to a variable called theclass. the forname method throws an exception if the value you pass it does not evaluate to the name of a java class. place the forname assignment statement in a try block to handle the exception, as follows: function getclass(javaclassname) { try { var theclass = java.lang.class.forname(javaclassname); } catch (e) { return ("the java exception is " + e); } return theclass; } in this example, if javaclassname evaluates to a legal class name, such as "java.lang.string", the assignment succeeds. if javaclassname evaluates to an invalid class name, such as "string", ...
...And 19 more matches

Control flow and error handling - JavaScript
nevertheless, not all thrown objects are created equal. while it is common to throw numbers or strings as errors, it is frequently more effective to use one of the e...
... 'cherries': console.log('cherries are $3.00 a pound.'); break; case 'mangoes': console.log('mangoes are $0.56 a pound.'); break; case 'papayas': console.log('mangoes and papayas are $2.79 a pound.'); break; default: console.log(`sorry, we are out of ${fruittype}.`); } console.log("is there anything else you'd like?"); exception handling statements you can throw exceptions using the throw statement and handle them using the try...catch statements. throw statement try...catch statement exception types just about any object can be thrown in javascript. nevertheless, not all thrown objects are created equal. while it is common to throw numbers or strings as errors, it is frequently more effective to use one of the exception types specifically created for this ...
...ment and handle them using the try...catch statements. throw statement try...catch statement exception types just about any object can be thrown in javascript. nevertheless, not all thrown objects are created equal. while it is common to throw numbers or strings as errors, it is frequently more effective to use one of the exception types specifically created for this purpose: ecmascript exceptions domexception and domerror throw statement use the throw statement to throw an exception. a throw statement specifies the value to be thrown: throw expression; you may throw any expression, not just expressions of a specific type. ...
...And 16 more matches

nsIMsgHeaderParser
iven a string which contains a list of header addresses, returns a comma-separated list of just the 'mailbox' portions. if any of the addresses doesn't have a mailbox, then the user name is used instead. autf8string extractheaderaddressmailboxes( in string line ); parameters line the header line to parse. return value a comma-separated list of just the mailbox parts of the addresses. exceptions thrown missing exception missing description native code only!extractheaderaddressnames given a string which contains a list of header addresses, returns a comma-separated list of just the 'user name' portions. if any of the addresses doesn't have a name, then the mailbox is used instead. autf8string extractheaderaddressnames( in string line ); parameters line the header line to...
...snames given a string which contains a list of header addresses, returns a comma-separated list of just the 'user name' portions. if any of the addresses doesn't have a name, then the mailbox is used instead. autf8string extractheaderaddressnames( in string line ); parameters line the header line to parse. return value a comma-separated list of just the name parts of the addresses. ...
...contains a list of header addresses, returns a comma-separated list of just the 'user name' portions. if any of the addresses doesn't have a name, then the mailbox is used instead. autf8string extractheaderaddressnames( in string line ); parameters line the header line to parse. return value a comma-separated list of just the name parts of the addresses. ...
...And 14 more matches

nsIRadioInterfaceLayer
void dial( in domstring number ); parameters number missing description ex...
..._disconnected 10 call_state_incoming 11 datacall_state_unknown 0 datacall_state_connecting 1 datacall_state_connected 2 datacall_state_disconnecting 3 datacall_state_disconnected 4 call_state_ringing 2 obsolete since gecko 14.0 methods answercall() void answercall( in unsigned long callindex ); parameters callindex missing description exceptions thrown missing exception missing description deactivatedatacall() void deactivatedatacall( in domstring cid, in domstring reason ); parameters cid missing description reason missing description exceptions thrown missing exception missing description dial() functionality for making and managing phone calls. void dial( in domstring number ); parameters number missing description exceptions thrown missing ex...
... dial() functionality for making and managing phone calls. void dial( in domstring number ); parameters number missing description exceptions thrown missing exception missing description enumeratecalls() will continue calling callback.enumeratecallstate until the callback returns false. void enumeratecalls( in nsiriltelephonycallback callback ); parameters callback missing description exceptions thrown missing exception missing description getdatacalllist() void getdatacalllist(); parameters none. exceptions thrown missing exception missing description getnumberofmessagesfortext() returns the number of multi-part sms needed for a given text (160 characters for one sms). unsigned short getnumberofmessagesfortext( in domstring text ); parameters text the body text of an sms. ret...
...And 14 more matches

try...catch - JavaScript
the try...catch statement marks a block of statements to try and specifies a response should an exception be thrown. the source for this interactive example is stored in a github repository. if you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request. syntax try { try_statements } [catch (exception_var_1 if condition_1) { // non-standard catch_statements_1 }] ... [catch (exception_var_2) { catch_statements_2 }] [finally { finally_statements }] try_statements the statements to be executed. ...
...github.com/mdn/interactive-examples and send us a pull request. syntax try { try_statements } [catch (exception_var_1 if condition_1) { // non-standard catch_statements_1 }] ... [catch (exception_var_2) { catch_statements_2 }] [finally { finally_statements }] try_statements the statements to be executed. catch_statements_1, catch_statements_2 statements that are executed if an exception is thrown in the try-block. exception_var_1, exception_var_2 an identifier to hold an exception object for the associated catch-block. condition_1 a conditional expression. finally_statements statements that are executed after the try statement completes. these statements execute regardless of whether an exception was thrown or caught. description the try statement consists of a...
...s thrown or caught. description the try statement consists of a try-block, which contains one or more statements. {} must always be used, even for single statements. at least one catch-block, or a finally-block, must be present. this gives us three forms for the try statement: try...catch try...finally try...catch...finally a catch-block contains statements that specify what to do if an exception is thrown in the try-block. if any statement within the try-block (or in a function called from within the try-block) throws an exception, control is immediately shifted to the catch-block. if no exception is thrown in the try-block, the catch-block is skipped. the finally-block will always execute after the try-block and catch-block(s) have finished executing. it always executes, regardless of ...
...And 14 more matches

nsIFile
astring newname); void remove(in boolean recursive); void reveal(); void setrelativedescriptor(in nsifile fromfile, in acstring relativedesc); attributes attribute type description directoryentries nsisimpleenumerator returns an enumeration of the elements in a directory. each element in the enumeration is an nsifile. read only. exceptions thrown ns_error_file_not_directory indicates that this nsifile does not reference a directory. diskspaceavailable print64 the number of bytes available to non-superuser on the disk volume containing the nsifile. read only. filesize print64 the value of this attribute is the number of bytes corresponding to the data represented by the fi...
...anteed to be a usable path to pass to nspr or the c stdlib. there are problems that affect platforms on which a path does not fully specify a file because two volumes can have the same name (for example mac). this is solved by holding "private", native data in the nsifile implementation. this native data is lost when you convert to a string. do not pass to use with nspr or stdlib! read only. exceptions thrown ns_error_file_invalid_path indicates that this nsifile does not reference a symbolic link. constants constant value description normal_file_type 0 a normal file. directory_type 1 a directory/folder. delete_on_close 0x80000000 optional parameter used by opennsprfiledesc methods append() th...
... this function is used for constructing a descendant of the current nsifile. note: this method does not return a new nsifile; it modifies the object it was called on. if the old nsifile should be retained, use clone(). void append( in astring node ); parameters node a string which is intended to be a child node of the nsifile. this string must not contain a path separator character. exceptions thrown ns_error_file_unrecognized_path indicates that anode incorrectly contains a path separator character. native code only! appendnative this method is used for constructing a descendant of the current nsifile. [native character encoding variant] void appendnative( in acstring node ); parameters node a string that is intended to be a child node of the current nsifile. th...
...And 12 more matches

nsIHttpChannel
to indicate whether or not the underlying http transaction should be allowed to be pipelined with other transactions. this should be set to false, for example, if the application knows that the corresponding document is likely to be very large. this attribute is true by default, though other factors may prevent pipelining. this attribute may only be set before the channel is opened. exceptions thrown ns_error_failure if set after the channel has been opened. redirectionlimit unsigned long this attribute specifies the number of redirects this channel is allowed to make. if zero, the channel will fail to redirect and will generate a ns_error_redirect_loop failure status. note: an http redirect results in a new channel being created.
... from which this channel's uri was obtained (see rfc2616 section 14.36). this attribute may only be set before the channel is opened. note: the channel may silently refuse to set the referer: header if the uri does not pass certain security checks (e.g., a "https://" url will never be sent as the referrer for a plaintext http request). the implementation is not required to throw an exception when the referrer uri is rejected. exceptions thrown ns_error_in_progress if set after the channel has been opened. ns_error_failure if used for setting referrer during visitrequestheaders(). getting the value will not throw. requestmethod acstring set or get the http request method (default is "get"). setter is case insensitive; g...
...get"). setter is case insensitive; getter returns an uppercase string. this attribute may only be set before the channel is opened. note: the data for a "post" or "put" request can be configured via nsiuploadchannel. however, after setting the upload data, it may be necessary to set the request method explicitly. the documentation for nsiuploadchannel has further details. exceptions thrown ns_error_in_progress if set after the channel has been opened. requestsucceeded boolean returns true if the http response code indicates success. the value of nsirequest.status() will be ns_ok even when processing a 404 file not found response because such a response may include a message body that (in some cases) should be shown to the user. u...
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JSAPI User Guide
o c++ types and store them in local variables. the native function uses js_set_rval(cx, vp, val) to store its javascript return value. on success, a jsnative must call js_set_rval and return true. the value passed to js_set_rval is returned to the javascript caller. on failure, a jsnative calls an error-reporting function, in this case js_reporterror, and returns false. this causes a javascript exception to be thrown. the caller can catch the exception using a javascript try/catch statement. to make native functions callable from javascript, declare a table of jsfunctionspecs describing the functions. then call js_definefunctions. static jsfunctionspec myjs_global_functions[] = { js_fs("rand", myjs_rand, 0, 0), js_fs("srand", myjs_srand, 0, 0), js_fs("system", myjs_system, 1, ...
...pt to grow the process. this means that garbage collection typically happens when memory-intensive code is running, perhaps the worst possible time. an application can trigger garbage collection at a more convenient time by calling js_gc or js_maybegc. js_gc forces garbage collection. js_maybegc performs garbage collection only if it is likely to reclaim a worthwhile amount of memory. errors and exceptions the importance of checking the return value of jsapi functions, of course, goes without saying. almost every jsapi function that takes a jscontext * argument can fail. the system might run out of memory. there might be a syntax error in a script. or a script might explicitly throw an exception. the javascript language has exceptions, and c++ has exceptions, but they are not the same thing. spi...
...ng the return value of jsapi functions, of course, goes without saying. almost every jsapi function that takes a jscontext * argument can fail. the system might run out of memory. there might be a syntax error in a script. or a script might explicitly throw an exception. the javascript language has exceptions, and c++ has exceptions, but they are not the same thing. spidermonkey does not use c++ exceptions for anything. jsapi functions never throw c++ exceptions, and when spidermonkey calls an application callback, the callback must not throw a c++ exception. throwing and catching exceptions we have already seen one example of how to throw an exception from a jsnative function. simply call js_reporterror, with printf-style arguments, and return false. rc = system(cmd); if (rc != 0) { ...
...And 11 more matches

Debugger - Firefox Developer Tools
nary form. the webassembly text generation will be disabled. collectcoverageinfo a boolean value indicating whether code coverage should be enabled inside each debuggee of this debugger instance. changing this flag value will recompile all jit code to add or remove code coverage instrumentation. changing this flag when any frame of the debuggee is currently active on the stack will produce an exception. setting this to true enables code coverage instrumentation, which can be accessed via the debugger.script getoffsetscoverage function. in some cases, the code coverage might expose information which pre-date the modification of this flag. code coverage reports are monotone, thus one can take a snapshot when the debugger is enabled, and output the difference. setting this to false prevents th...
...ses, the code coverage might expose information which pre-date the modification of this flag. code coverage reports are monotone, thus one can take a snapshot when the debugger is enabled, and output the difference. setting this to false prevents this debugger instance from requiring any code coverage instrumentation, but it does not guarantee that the instrumentation is not present. ...
...t when the debugger is enabled, and output the difference. setting this to false prevents this debugger instance from requiring any code coverage instrumentation, but it does not guarantee that the instrumentation is not present. uncaughtexceptionhook either null or a function that spidermonkey calls when a call to a debug event handler, breakpoint handler, or similar function throws some exception, which we refer to asdebugger-exception here. ...
...And 11 more matches

FileSystemEntrySync - Web APIs
olders that are stored in the origin of your app. just use filesystem: scheme for the root directory of the origin of the app. for example, if your app is in http://ww.html5rocks.com, open filesystem:http://www.html5rocks.com/temporary/ in a tab. chrome shows a read-only list of all the files and folders stored the origin of your app. ...
...he app. for example, if your app is in http://ww.html5rocks.com, open filesystem:http://www.html5rocks.com/temporary/ in a tab. chrome shows a read-only list of all the files and folders stored the origin of your app. method overview metadata getmetadata () raises (fileexception); filesystementrysync moveto (in directoryentrysync parent, optional domstring newname) raises (fileexception); filesystementrysync copyto(in directoryentrysync parent, optional domstring newname) raises (fileexception); domstring tourl(); void remove() raises (fileexception); directoryentrysync getparent(); attributes attribute type description filesystem readonly filesystemsync the file system where the entry resides. ...
...isdirectory readonly boolean true if filesystementrysync is a directory. isfile readonly boolean true if the filesystementrysync is a file. name readonly domstring the name of the entry, excluding the path leading to it. methods getmetadata() look up metadata about this entry. [ todo: specify what kind of metadata ] metadata getmetada () raises (fileexception); parameter none returns metadata exceptions this method can raise a fileexception with the following codes: exception description not_found_err the entry does not exist. invalid_state_err the filesystemsync is no longer valid for some reason besides being deleted. moveto() move an entry to a different location on the file system. movin...
...And 11 more matches

IDBIndexSync - Web APIs
ended for use only with web workers, and was eventually removed from the spec because its need was questionable. it may however be reintroduced in the future if there is enough demand from web developers. the idbindexsync interface of the indexeddb api provides synchronous access to an index in a database. ...
...ed from the spec because its need was questionable. it may however be reintroduced in the future if there is enough demand from web developers. the idbindexsync interface of the indexeddb api provides synchronous access to an index in a database. ...
...be reintroduced in the future if there is enough demand from web developers. the idbindexsync interface of the indexeddb api provides synchronous access to an index in a database. ...
...And 11 more matches

IDBObjectStoreSync - Web APIs
only with web workers, and was eventually removed from the spec because its need was questionable. it may however be reintroduced in the future if there is enough demand from web developers. the idbobjectstoresync interface of the indexeddb api provides synchronous access to an object store of a database. ...
.... the idbobjectstoresync interface of the indexeddb api provides synchronous access to an object store of a database. ...
... any add (in any value, in optional any key) raises (idbdatabaseexception); idbindexsync createindex (in domstring name, in domstring storename, in domstring keypath, in optional boolean unique); any get (in any key) raises (idbdatabaseexception); idbcursorsync opencursor (in optional idbkeyrange range, in optional unsigned short direction) raises (idbdatabaseexception); idbindexsync openindex (in domstring name) raises (idbdatabaseexception); any put (in any value, in optional any key) raises (idbdatabaseexception); void remove (in any key) raises (idbdatabaseexception); void removeindex (in domstring indexname) raises (idbdatabaseexception); attributes attribute type description indexna...
...And 10 more matches

throw - JavaScript
the throw statement throws a user-defined exception. execution of the current function will stop (the statements after throw won't be executed), and control will be passed to the first catch block in the call stack. if no catch block exists among caller functions, the program will terminate. the source for this interactive example is stored in a github repository. if you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request. syntax throw expression; expression the expression to throw. description use the throw statement to throw an exception. when you throw an exception, expression specifies the value of the exception. ...
...pository. if you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request. syntax throw expression; expression the expression to throw. description use the throw statement to throw an exception. when you throw an exception, expression specifies the value of the exception. ...
... interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request. syntax throw expression; expression the expression to throw. description use the throw statement to throw an exception. when you throw an exception, expression specifies the value of the exception. each of the following throws an exception: throw 'error2'; // generates an exception with a string value throw 42; // generates an exception with the value 42 throw true; // generates an exception with the value true throw new error('required'); // generates an error object with the message of required also note that the throw statement is affected by automatic semicolon insertion (asi) as no line terminator between the throw keyword and the expression is allowed. e...
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Scripting Java
y was available only to embeddings that used org.mozilla.javascript.importertoplevel class as the top level scope. the class provides additional importpackage() and importclass() global functions for scripts but their extensive usage has tendency to pollute the global name space with names of java classes and prevents loaded classes from garbage collection. see bugzilla 245882 for details. ...
...ble only to embeddings that used org.mozilla.javascript.importertoplevel class as the top level scope. the class provides additional importpackage() and importclass() global functions for scripts but their extensive usage has tendency to pollute the global name space with names of java classes and prevents loaded classes from garbage collection. see bugzilla 245882 for details. ...
...provides additional importpackage() and importclass() global functions for scripts but their extensive usage has tendency to pollute the global name space with names of java classes and prevents loaded classes from garbage collection. see bugzilla 245882 for details. java exceptions exceptions thrown by java methods can be caught by javascript code using try...catch statement. ...
...And 8 more matches

test/assert - Archive of obsolete content
e different exports["test strict equality"] = function(assert) { assert.notstrictequal(1, "1", "test strict equality between 1 and '1'"); } parameters actual : object the actual result. expected : object the expected result. message : string optional message to log, providing extra information about the test. throws(block, error, message) assert that a block of code throws the expected exception. ...
...tequal(1, "1", "test strict equality between 1 and '1'"); } parameters actual : object the actual result. expected : object the expected result. message : string optional message to log, providing extra information about the test. throws(block, error, message) assert that a block of code throws the expected exception. ...
...tual : object the actual result. expected : object the expected result. message : string optional message to log, providing extra information about the test. throws(block, error, message) assert that a block of code throws the expected exception. this method takes an optional error argument: to check that the exception thrown is of the expected type, pass a constructor function: the exception thrown must be an instance of the object returned by that function. ...
...And 7 more matches

Promise
illed, when and if the final value becomes available. a fulfillment value becomes permanently associated with the promise. this may be any value, including undefined. rejected, if an error prevented the final value from being determined. a rejection reason becomes permanently associated with the promise. this may be any value, including undefined, though it is generally an error object, like in exception handling. note: you should always handle, forward, or report errors (rejection reasons). if you see the message "a promise chain failed to handle a rejection", there is likely something to be fixed in the code. see handling errors and common pitfalls below. documentation conventions in documentation, the type of the fulfillment value is usually specified between angular brackets. for exampl...
... new promise(executor); parameters executor this function is invoked immediately with the resolving functions as its two arguments: executor(resolve, reject); the constructor will not return until the executor has completed. the resolving functions can be used at any time, before or after the executor has completed, to control the final state of the promise. if the executor throws an exception, its value will be passed to the reject resolving function. resolving functions resolve() fulfills the associated promise with the specified value, or propagates the state of an existing promise. if the associated promise has already been resolved, either to a value, a rejection, or another promise, this method does nothing. note: calling this method with a pending promise as the avalue ar...
...ture transitions). reject() rejects the associated promise with the specified reason. if the promise has already been resolved, either to a value, a rejection, or another promise, this method does nothing. void reject( areason ); parameters areason optional the rejection reason for the associated promise. although the reason can be undefined, it is generally an error object, like in exception handling. note: this argument should not be a promise. specifying a rejected promise would make the rejection reason equal to the rejected promise itself, and not its rejection reason. methods then() calls one of the provided functions as soon as this promise is either fulfilled or rejected. a new promise is returned, whose state evolves depending on this promise and the provided callbac...
...And 7 more matches

Task.jsm
keeping in mind that only the core subset is implemented in this module. tasks are built upon generator functions and promises. the task.spawn() function takes a generator function and starts running it as a task. every time the task yields a promise, it waits until the promise is resolved. task.spawn() returns a promise that is resolved when the task completes successfully, or is rejected if an exception occurs. you can use the yield operator inside the generator function to wait on a promise, spawn another task, or propagate a value: let resolutionvalue = yield (promise/generator/iterator/value); if you specify a promise, the yield operator returns its resolution value as soon as the promise is resolved. if the promise is rejected, its rejection reason is thrown as an exception. if you spe...
...in handy when iterating over function lists where some items have been converted to tasks and some not. if you specify anything else, the yield operator returns exactly what you specified. method overview function async(atask); promise spawn(atask); properties attribute type description result read only constructor constructs a special exception that, when thrown inside a legacy generator function, allows the associated task to be resolved with a specific value. example: task.spawn( function() { yield ... ; throw new task.result("value"); } note: if you want to exit early from a generator function, without returning a value for the task, you can just use the return statement without any arguments. note: if you want to retu...
...with the thrown error if the generator throws. if you specify a function that is not a generator, it is called with no arguments, and its return value is used to fulfill the returned promise. if you specify anything else, you get a promise that is already fulfilled with the specified value. return value a promise that is fulfills when the task returns or rejects when the task throws an exception. examples general example cu.import("resource://gre/modules/task.jsm"); task.spawn(function* () { // this is our task. it is a generator function because it contains the // "yield" operator at least once. let's create a promise object, wait on // it and capture its resolution value. let mypromise = getpromiseresolvedontimeoutwithvalue(1000, "value"); let result = yield mypromise;...
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Bytecode Descriptions
r and jsop::enditer, or by error handling. the script's jsscript::trynotes() must mark the body of the for-in loop, i.e. exactly those instructions that begin executing with iter on the stack, starting with the next instruction (always jsop::loophead). code must not jump into or out of this region: control can enter only by executing jsop::iter and can exit only by executing a jsop::enditer or by exception unwinding. (a jsop::enditer is always emitted at the end of the loop, and extra copies are emitted on "exit slides", where a break, continue, or return statement exits the loop.) typically a single try note entry marks the contiguous chunk of bytecode from the instruction after jsop::iter to jsop::enditer (inclusive); but if that range contains any instructions on exit slides, after a jsop::endit...
...ex) stack: ⇒ regexp clone and push a new regexp object. implements: evaluation for regularexpressionliteral. functions creating functions lambda operands: (uint32_t funcindex) stack: ⇒ fn push a function object. this clones the function unless it's a singleton; see canreusefunctionforclone. the new function inherits the current environment chain. used to create most js functions. notable exceptions are arrow functions and derived or default class constructors. the function indicated by funcindex must be a non-arrow function. implements: instantiatefunctionobject, evaluation for functionexpression, and so on. format: jof_object lambdaarrow operands: (uint32_t funcindex) stack: newtarget ⇒ arrowfn push a new arrow function. newtarget matters only if the arrow function uses the expressio...
...es one of the generatorresumekind values as int32value. checkresumekind stack: rval, gen, resumekind ⇒ rval handle throw and return resumption. gen must be the generator object for the current frame. resumekind must be a generatorresumekind stored as an int32 value. if it is next, continue to the next instruction. if resumekind is throw or return, these completions are handled by throwing an exception. see generatorthroworreturn. resume stack: gen, val, resumekind ⇒ rval resume execution of a generator, async function, or async generator. this behaves something like a call instruction. it pushes a stack frame (the one saved when gen was suspended, rather than a fresh one) and runs instructions in it. once gen returns or yields, its return value is pushed to this frame's stack and executio...
...And 7 more matches

Index
reflected into javascript. the components object is actually a native instance of the nsixpccomponents interface which is reflected into javascript as a top level object using xpconnect. 17 components.constructor xpcom:language bindings, xpconnect creates a javascript function which can be used to create or construct new instances of xpcom components. 18 components.exception xpcom:language bindings, xpconnect components.exception is a javascript constructor to create nsixpcexception objects. these exception objects may be thrown when implementing xpcom interfaces in javascript, and they can provide better diagnostics in the error console if not caught than simply throwing an nsresult's value will. 19 components.id xpcom:language bindings, xpc...
...review, xpcom:language bindings, xpconnect ensures that the specified object's methods are all in the object's scope, and aren't cross-component wrappers. 44 components.utils.reporterror xpcom:language bindings, xpconnect components.utils.reporterror reports a javascript error object to the error console, and returns. it is meant for use by extension developers who have exception handler blocks which want to "eat" an exception, but still want to report it to the console. 45 components.utils.scheduleprecisegc guide, needscontent, xpcom, xpcom:language bindings, xpconnect this method lets scripts schedule a garbage collection cycle. the garbage collection cycle will occur sometime in the future, when no javascript code is executing. this is useful parti...
...his context, if it is an nsisupports, |null| otherwise. retrieve the underlying context wrapped by this jsdicontext. top of the scope chain for this context. |true| if this context should be allowed to run scripts, |false| otherwise. this attribute is only valid for contexts which implement nsiscriptcontext. setting or getting this attribute on any other context will throw a ns_error_no_interface exception. stack frame objects. these are only valid inside the jsdiexecutionhook which gave it to you. after you return from that handler the bottom frame, and any frame you found attached through it, are invalidated via the jsdiephemeral interface. once a jsdistackframe has been invalidated all method and property accesses will throw a ns_error_not_available exception. 193 moziasyncfavicons ...
...And 7 more matches

SVGTransform - Web APIs
svg transform interface svgtransform is the interface for one of the component transformations within an svgtransformlist; thus, an svgtransform object corresponds to a single component (e.g., scale(…) or matrix(…)) within a transform attribute. an svgtransform object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown. interface overview also implement none methods void setmatrix(in svgmatrix matrix) void settranslate(in float tx, in float ty) void setscale(in float sx, in float sy) void setrotate(in float angle, in float cx, in float cy) void setskewx(in float angle) void setskewy(in float angle) properties readonly unsigned short...
... the given rotation. when the rotation is around the center point (0, 0), e and f will be zero. methods name & arguments return description setmatrix(in svgmatrix matrix) void sets the transform type to svg_transform_matrix, with parameter matrix defining the new transformation. note that the values from the parameter matrix are copied. ...
...e rotation is around the center point (0, 0), e and f will be zero. methods name & arguments return description setmatrix(in svgmatrix matrix) void sets the transform type to svg_transform_matrix, with parameter matrix defining the new transformation. note that the values from the parameter matrix are copied. ...
...And 7 more matches

SVGTransformList - Web APIs
svg transform list interface the svgtransformlist defines a list of svgtransform objects. an svgtransformlist object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown. note: starting in gecko 9.0,the svgtransformlist dom interface is now indexable and can be accessed like arrays interface overview also implement none methods void clear() svgtransform initialize(in svgtransform newitem) svgtransform getitem(in unsigned long index) svgtransform insertitembefore(in svgtransform newitem, in unsigned long index) svgtransform replaceitem(in svgtransform newitem, in unsigned long index) svgtransform removeitem(in unsigned long index) svgtransform appenditem(in svgt...
... properties name type description numberofitems unsigned long the number of items in the list. length unsigned long the number of items in the list. methods name & arguments return description clear() void clears all existing current items from the list, with the result being an empty list. exceptions: a domexception with code no_modification_allowed_err is raised when the list corresponds to a read only attribute or when the object itself is read only. initialize(in svgtransform newitem) svgtransform clears all existing current items from the list and re-initializes the list to hold the single item specified by the parameter. if the inserted item is al...
...transform newitem) svgtransform clears all existing current items from the list and re-initializes the list to hold the single item specified by the parameter. if the inserted item is already in a list, it is removed from its previous list before it is inserted into this list. the inserted item is the item itself and not a copy. the return value is the item inserted into the list. exceptions: a domexception with code no_modification_allowed_err is raised when the list corresponds to a read only attribute or when the object itself is read only. getitem(in unsigned long index) svgtransform returns the specified item from the list. the returned item is the item itself and not a copy. any changes made to the item are immediately reflected in the l...
...And 7 more matches

nsIZipWriter
irefox 3) once all the operations you wish to perform are added to the queue, a call to processqueue() will perform the operations in the order they were added to the queue. operations performed on the queue throw any errors that occur out to the observer. attempting to perform a synchronous operation on the interface while the background queue is in progress will throw an ns_error_in_progress exception. file and directory names should use slashes ("/") as separators and should not begin with a slash. note: although it is not necessary to add directory entries in order to add file entries within them, some zip utilities may have problems with that, so it may be best to add the directory entries explicitly first. implemented by: @mozilla.org/zipwriter;1. to create an instance, use: var zipwri...
...ing azipentry); void open(in nsifile afile, in print32 aioflags); void processqueue(in nsirequestobserver aobserver, in nsisupports acontext); void removeentry(in autf8string azipentry, in boolean aqueue); attributes attribute type description comment acstring gets or sets the comment associated with the currently open zip file. exceptions thrown ns_error_not_initialized if no zip file has been opened. file nsifile the zip file being written to. read only. inqueue boolean true if operations are being performed in the background queue, or false if background operations are not in progress. read only. constants constant value description compressi...
...d slashes ('/') in the path. amodtime the modification time of the entry in microseconds. acompression one of the compression constants, indicating the compression method to use. achannel the channel from which to get the data. aqueue if true, the operation is queued for later execution. if false, the operation is performed immediately. will be performed when processqueue() is called. exceptions thrown ns_error_not_initialized no zip file is open. ns_error_file_already_exists the specified path already exists in the zip file. ns_error_in_progress the zip writer is already performing another operation. addentrydirectory() adds a new directory entry to the zip file. if azipentry does not end with "/" then it will be added. note: although it is not necessary to add directory en...
...And 6 more matches

IDBDatabaseSync - Web APIs
om the spec because its need was questionable. it may however be reintroduced in the future if there is enough demand from web developers. the databasesync interface in the indexeddb api represents a synchronous connection to a database. ...
...velopers. the databasesync interface in the indexeddb api represents a synchronous connection to a database. ...
...nection to a database. method overview idbobjectstoresync createobjectstore (in domstring name, in domstring keypath, in optional boolean autoincrement) raises (idbdatabaseexception); idbobjectstoresync openobjectstore (in domstring name, in optional unsigned short mode) raises (idbdatabaseexception); void removeobjectstore (in domstring storename) raises (idbdatabaseexception); void setversion (in domstring version); idbtransactionsync transaction (in optional domstringlist storenames, in optional unsigned int timeout) raises (idbdatabaseexception); attributes attribute type description description readonly domstring the human-readable description of the connected database. name readonly domstri...
...And 6 more matches

SVGLengthList - Web APIs
svg length list interface the svglengthlist defines a list of svglength objects. an svglengthlist object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown. note: starting in gecko 5.0,the svglengthlist dom interface is now indexable and can be accessed like arrays interface overview also implement none methods void clear() svglength initialize(in svglength newitem) svglength getitem(in unsigned long index) svglength insertitembefore(in svglength newitem, in unsigned long index) svglength replaceitem(in svglength newitem, in unsigned long index) svglength removeitem(in unsigned long index) svglength appenditem(in svglength newitem) properties ...
... properties name type description numberofitems unsigned long the number of items in the list. length unsigned long the number of items in the list. methods name & arguments return description clear() void clears all existing current items from the list, with the result being an empty list. exceptions: a domexception with code no_modification_allowed_err is raised when the list corresponds to a read only attribute or when the object itself is read only. initialize(in svglength newitem) svglength clears all existing current items from the list and re-initializes the list to hold the single item specified by the parameter. if the inserted item is already in a...
...e(in svglength newitem) svglength clears all existing current items from the list and re-initializes the list to hold the single item specified by the parameter. if the inserted item is already in a list, it is removed from its previous list before it is inserted into this list. the inserted item is the item itself and not a copy. the return value is the item inserted into the list. exceptions: a domexception with code no_modification_allowed_err is raised when the list corresponds to a read only attribute or when the object itself is read only. getitem(in unsigned long index) svglength returns the specified item from the list. the returned item is the item itself and not a copy. any changes made to the item are immediately reflected in the list. th...
...And 6 more matches

SVGNumberList - Web APIs
note: starting in gecko 5.0,the svgnumberlist dom interface is now indexable and can be accessed like arrays. ...
... properties name type description numberofitems unsigned long the number of items in the list. length unsigned long the number of items in the list. methods name & arguments return description clear() void clears all existing current items from the list, with the result being an empty list. exceptions: a domexception with code no_modification_allowed_err is raised when the list corresponds to a read only attribute or when the object itself is read only. initialize(in svgnumber newitem) svgnumber clears all existing current items from the list and re-initializes the list to hold the single item specified by newitem. if the inserted item is already in a l...
...alize(in svgnumber newitem) svgnumber clears all existing current items from the list and re-initializes the list to hold the single item specified by newitem. if the inserted item is already in a list, it is removed from its previous list before it is inserted into this list. the inserted item is the item itself and not a copy. the return value is the item inserted into the list. exceptions: a domexception with code no_modification_allowed_err is raised when the list corresponds to a read only attribute or when the object itself is read only. getitem(in unsigned long index) svgnumber returns the specified item from the list. the returned item is the item itself and not a copy. any changes made to the item are immediately reflected in the list...
...And 6 more matches

Index - Archive of obsolete content
opment, web development:tools the error console is a tool available in most mozilla-based applications that is used for reporting errors in the application chrome and in web pages user opens. it reports javascript-related errors and warnings, css errors and arbitrary messages from chrome code. in firefox, the error console can be opened from the tools menu or by ctrl-shift-j. 433 exception logging in javascript extensions, extensions:tools, guide, javascript, javascript:tools, tools, web development, web development:tools in versions of firefox prior to firefox 3, all javascript exceptions were always logged into the error console if they remained unhandled at the time execution returned back into c++ code. as a result, if, for example, c++ code called a javascript compon...
... 434 existing content this is a list of existing mozilla.org documentation. ...
... 434 existing content this is a list of existing mozilla.org documentation. it needs to be checked, prioritized, and migrated. ...
...And 5 more matches

SVGPointList - Web APIs
svg point list interface the svgpointlist defines a list of svgpoint objects. an svgpointlist object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown. interface overview also implement none methods void clear() svgpoint initialize(in svgpoint newitem) svgpoint getitem(in unsigned long index) svgpoint insertitembefore(in svgpoint newitem, in unsigned long index) svgpoint replaceitem(in svgpoint newitem, in unsigned long index) svgpoint removeitem(in unsigned long index) svgpoint appenditem(in svgpoint newitem) ...
... numberofitems unsigned long the number of items in the list. methods name & arguments return description clear() void clears all existing current items from the list, with the result being an empty list. exceptions: a domexception with code no_modification_allowed_err is raised when the list corresponds to a read only attribute or when the object itself is read only. initialize(in svgpoint newitem) svgpoint clears all existing current items from the list and re-initializes the list to hold the single item specif...
... svgpoint clears all existing current items from the list and re-initializes the list to hold the single item specified by the parameter. if the inserted item is already in a list, it is removed from its previous list before it is inserted into this list. the inserted item is the item itself and not a copy. the return value is the item inserted into the list. exceptions: a domexception with code no_modification_allowed_err is raised when the list corresponds to a read only attribute or when the object itself is read only. getitem(in unsigned long index) svgpoint returns the specified item from the list. the returned item is the item itself and not a copy. any changes...
...And 5 more matches

SVGStringList - Web APIs
svg string list interface the svgstringlist defines a list of domstring objects. an svgstringlist object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown. interface overview also implement none methods void clear() domstring initialize(in domstring newitem) domstring getitem(in unsigned long index) domstring insertitembefore(in domstring newitem, in unsigned long index) domstring replaceitem(in domstring newitem, in unsigned long index) domstring removeitem(in unsigned long index) domstring appenditem(in domstring newitem) properties readonly unsigned long numberofitems readonly unsigned long length norm...
...ription numberofitems unsigned long the number of items in the list. length unsigned long a mirror of the value in numberofitems, for consistency with other interfaces. methods name & arguments return description clear() void clears all existing current items from the list, with the result being an empty list. exceptions: a domexception with code no_modification_allowed_err is raised when the list corresponds to a read only attribute or when the object itself is read only. initialize(in domstring newitem) domstring clears all existing current items from the list and re-initializes the list to hold the single item specified by the parameter. if the inserted item is already ...
...in domstring newitem) domstring clears all existing current items from the list and re-initializes the list to hold the single item specified by the parameter. if the inserted item is already in a list, it is removed from its previous list before it is inserted into this list. the inserted item is the item itself and not a copy. the return value is the item inserted into the list. exceptions: a domexception with code no_modification_allowed_err is raised when the list corresponds to a read only attribute or when the object itself is read only. getitem(in unsigned long index) domstring returns the specified item from the list. the returned item is the item itself and not a copy. any changes made to the item are immediately reflected in the list...
...And 5 more matches

console - Archive of obsolete content
essages appear in the browser console. if you're developing your add-on using the extension auto-installer, then the add-on is installed in firefox, meaning that messages will appear in the browser console. but see the discussion of logging levels: by default, messages logged using log(), info(), trace(), or warn() won't be logged in these situations. console methods all console methods except exception() and trace() accept one or more javascript objects as arguments and log them to the console. depending on the console's underlying implementation and user interface, you may be able to examine the properties of non-primitive objects that are logged. console.debug(...) deprecated, you should use console.log() instead. console.error(object[, object, ...]) logs the arguments to the console, pre...
...on and user interface, you may be able to examine the properties of non-primitive objects that are logged. console.debug(...) deprecated, you should use console.log() instead. ...
...r interface, you may be able to examine the properties of non-primitive objects that are logged. console.debug(...) deprecated, you should use console.log() instead. ...
...And 4 more matches

JSAPI Cookbook
i * * warning: this only works for integers that fit in 32 bits. * otherwise, convert the number to floating point (see the next example). */ js::callargs args = js::callargsfromvp(argc, vp); args.rval().setint32(23); return true; returning a floating-point number // javascript return 3.14159; /* jsapi */ js::callargs args = js::callargsfromvp(argc, vp); args.rval().setdouble(3.14159); exception handling throw the most common idiom is to create a new error object and throw that. js_reporterror does this. note that javascript exceptions are not the same thing as c++ exceptions. the jsapi code also has to return false to signal failure to the caller. // javascript throw new error("failed to grow " + varietal + ": too many greenflies."); /* jsapi */ js_reporterror(cx, "failed to grow %...
...ror("failed to grow " + varietal + ": too many greenflies."); /* jsapi */ js_reporterror(cx, "failed to grow %s: too many greenflies.", varietal); return false; to internationalize your error messages, and to throw other error types, such as syntaxerror or typeerror, use js_reporterrornumber instead. javascript also supports throwing any value at all, not just error objects. use js_setpendingexception to throw an arbitrary js::value from c/c++. // javascript throw exc; /* jsapi */ js_setpendingexception(cx, exc); return false; when js_reporterror creates a new error object, it sets the filename and linenumber properties to the line of javascript code currently at the top of the stack. this is usually the line of code that called your native function, so it's usually what you want. jsapi c...
... return throwerror(cx, global, message, __file__, __line__); the jsapi code here is actually simulating throw error(message) without the new, as new is a bit harder to simulate using the jsapi. in this case, unless the script has redefined error, it amounts to the same thing. catch // javascript try { // try some stuff here; for example: foo(); b...
...And 4 more matches

nsICrashReporter
m/system/nsicrashreporter.idlscriptable provides access to crash reporting functionality. ...
...ble provides access to crash reporting functionality. ...
.... 1.0 66 introduced gecko 1.9 inherits from: nsisupports last changed in gecko 2.0 (firefox 4 / thunderbird 3.3 / seamonkey 2.1) method overview void annotatecrashreport(in acstring key, in acstring data); void appendappnotestocrashreport(in acstring data); void appendobjcexceptioninfotoappnotes(in voidptr aexception); native code only! void writeminidumpforexception(in voidptr aexceptioninfo); native code only! attributes attribute type description enabled boolean enable or disable the crashreporter at runtime. minidumppath nsilocalfile get or set the path on the local system to which minidumps will be written when a crash happens. exceptions thrown ns_error_not_initialized if crash reporting is not initialized. serverurl nsiurl get or set t...
...And 4 more matches

nsIFaviconService
n is dispatched through the observer's service. void expireallfavicons(); parameters none. getfavicondata() obsolete since gecko 22.0 (firefox 22.0 / thunderbird 22.0 / seamonkey 2.19) note: this method was removed in gecko 22.0. you should use the new async api moziasyncfavicons.getfavicondataforpage() instead. this method retrieves the given favicon data. throws an exception if we don't have data. if there is no data but we have an entry for this favicon, adatalen will be "0" and adata will be null. void getfavicondata( in nsiuri afaviconuri, out autf8string amimetype, out unsigned long adatalen, optional from gecko 2.0 [array,retval,size_is(adatalen)] out octet adata ); parameters afaviconuri uri of the favicon whose data is being read. amimety...
...ctet adata ); parameters afaviconuri uri of the favicon whose data is being read. amimetype output parameter where the mime type will be placed. adatalen output parameter where the size of the binary data will be placed. adata output parameter where the binary favicon data will be placed. this will be null if we have this uri but have no data associated with it. exceptions thrown ns_error_not_available thrown when we have never heard of this favicon url. getfavicondataasdataurl() obsolete since gecko 22.0 (firefox 22.0 / thunderbird 22.0 / seamonkey 2.19) note: this method was removed in gecko 22.0. you should use the new async api moziasyncfavicons.getfavicondataforpage() instead. this method retrieves the given favicon data...
... thrown when we have never heard of this favicon url. getfavicondataasdataurl() obsolete since gecko 22.0 (firefox 22.0 / thunderbird 22.0 / seamonkey 2.19) note: this method was removed in gecko 22.0. you should use the new async api moziasyncfavicons.getfavicondataforpage() instead. ...
...And 4 more matches

nsIOutputStream
iinputstream afromstream, in unsigned long acount); unsigned long writesegments(in nsreadsegmentfun areader, in voidptr aclosure, in unsigned long acount); native code only! methods close() close the stream. forces the output stream to flush() any buffered data. note: this method may be called more than once, but subsequent calls are ignored. void close(); parameters none. exceptions thrown ns_base_stream_would_block indicates that closing the output stream would block the calling thread for an indeterminate amount of time. this exception may only be thrown if isnonblocking() returns true. flush() this method may be called to instruct the output stream to write out the contents of any internal buffers to a low-level data sink, such as a file on disk. however, the flus...
... isnonblocking() note: writing to a blocking output stream will block the calling thread until all given data can be consumed by the stream. ...
... write out the contents of any internal buffers to a low-level data sink, such as a file on disk. however, the flush method may simply do nothing depending on the implementation of the output stream. void flush(); parameters none. exceptions thrown ns_base_stream_would_block indicates that flushing the output stream would block the calling thread for an indeterminate amount of time. this exception may only be thrown if isnonblocking() returns true. isnonblocking() note: writing to a blocking output stream will block the calling thread until all given data can be consumed by the stream. note: a non-blocking output stream may implement nsiasyncoutputstream to provide consumers with a way to wait for the stream to accept more data once its write() method is unable to accept any data witho...
...And 4 more matches

nsIScriptableIO
lf. nsifile getfile( in astring alocation, in astring afilename ); parameters alocation a location key identifying a known standard directory. the afilename parameter is treated as being local to this directory. afilename the relative path of the file to generate a reference for. return value returns an nsifile object referencing the specified file location. exceptions thrown ns_error_invalid_arg alocation was null. getfilewithpath() returns a file reference using an absolute file path to locate the file. note: you should avoid using this method, since file paths are platform-dependent and non-portable. instead, you should use getfile() and construct the path from the base location manually. nsifile getfilewithpath( in astring afilepath );...
...s are platform-dependent and non-portable. instead, you should use getfile() and construct the path from the base location manually. nsifile getfilewithpath( in astring afilepath ); parameters afilepath the absolute pathname of the file to reference, or the value of a file's persistentdescriptor. return value returns an nsifile object referencing the specified file location. exceptions thrown ns_error_invalid_arg afilepath was null. newuri() creates a uri object that implements the nsiuri interface. nsiuri newuri( in nsivariant auri ); parameters auri the file for which to create a new nsiuri object. this parameter may be specified either as a url string or as an nsifile object. return value returns an nsiuri object corresponding to the sp...
...r_invalid_arg afilepath was null. newuri() creates a uri object that implements the nsiuri interface. nsiuri newuri( in nsivariant auri ); parameters auri the file for which to create a new nsiuri object. this parameter may be specified either as a url string or as an nsifile object. return value returns an nsiuri object corresponding to the specified string or file. exceptions thrown ns_error_invalid_arg auri was null. newinputstream() retrieves a stream from which data can be read. nsisupports newinputstream( in nsivariant abase, in astring amode, [optional] in astring acharset, [optional] in astring areplacechar, [optional] in unsigned long abuffersize ); parameters abase the base object from which to read. this shoul...
...And 4 more matches

nsITextInputProcessor
is specified, defaultprevented attribute of dispatching keyboard events true. this is not useful in usual cases. this may be useful for automated tests. key_non_printable_key 0x00000002 one of akeyflags. when you attempt to dispatch a non-printable key's events, it's recommented this be specified. if the key attribute value is not a registered key name, this flag causes throwing an exception. therefore, this can prevent non-printable key events to cause dispatching as printable keyboard events and you can detect the registered key name change from the thrown exception. key_force_printable_key 0x00000004 one of akeyflags. when you attempt to dispatch a printable key's event whose key attribute value (i.e., inputting string) will match with a registered key name, this fl...
...of akeyflags. the location attribute value of dispatching keyboard events is computed automatically if the attribute isn't initialized or initialized with 0. for the latter case, you may not want textinputprocessor to compute location attribute value. in this case, you can suppress the computation with this flag. if this is specified with non-zero location attribute value, this causes throwing an exception since it doesn't make sense. key_keep_keycode_zero 0x00000010 one of akeyflags. the keycode attribute value of dispatching printable keyboard events is computed from key value automatically if the attribute isn't initialized or initialized with 0. for the latter case, you may not want textinputprocessor to compute keycode attribute value. in this case, you can suppress the computat...
... dispatching keyboard events, you need to dispatch modifier key events before and after that. however, especially for keeping compatibility with legacy api, you may want to modify only the modifier state of a textinputprocessor instance. in this case, you can suppress textinputprocessor dispatches modifier key events with this flag. if this is specified for non-modifier key, it causes throwing an exception since it doesn't make sense. methods appendclausetopendingcomposition() appends a clause to the pending composition string which is set by setpendingcompositionstring(). sum of alength must be same as the length of astring of setpendingcompositionstring(). void appendclausetopendingcomposition(in unsigned long alength, in unsigned long aattribute); ...
...And 4 more matches

Debugger.Frame - Firefox Developer Tools
more than one debugger instance is debugging the same code, each debugger gets a separate debugger.frame instance for a given frame. this allows the code using each debugger instance to place whatever properties it likes on its debugger.frame instances, without worrying about interfering with other debuggers.) when the debuggee pops a stack frame (say, because a function call has returned or an exception has been thrown from it), the debugger.frame instance referring to that frame becomes inactive: its live property becomes false, and accessing its other properties or calling its methods throws an exception. note that frames only become inactive at times that are predictable for the debugger: when the debuggee runs, or when the debugger removes frames from the stack itself. visible frames when ...
... frame on the stack, witholder as its older property. invoke the debuggee code as appropriate for the given invocation function, with the "debugger" frame as its continuation. for example, debugger.frame.prototype.eval pushes an "eval" frame for code it runs, whereas debugger.object.prototype.call pushes a "call" frame. when the debuggee code completes, whether by returning, throwing an exception or being terminated, pop the "debugger" frame, and return an appropriate completion value from the invocation function to the debugger. when a debugger calls an invocation function to run debuggee code, that code’s continuation is the debugger, not the next debuggee code frame. pushing a "debugger" frame makes this continuation explicit, and makes it easier to find the extent of the stack c...
...ger.frame instance as the this value. the function should return a resumption value indicating how execution should proceed. on newly created frames, this property’s value is undefined. when this handler is called, this frame’s current execution location, as reflected in its offset and environment properties, is the operation which caused it to be unwound. in frames returning or throwing an exception, the location is often a return or a throw statement. in frames propagating exceptions, the location is a call. when an onpop call reports the completion of a construction call (that is, a function called via the new operator), the completion value passed to the handler describes the value returned by the function body. if this value is not an object, it may be different from the value produced...
...And 4 more matches

DirectoryEntrySync - Web APIs
tory. var fileentry = fs.root.getfile('seekrits.txt', {create: true}); the getdirectory() method returns a directoryentrysync, which represents a file in the file system. the following creates a new directory called superseekrit in the root directory. var direntry = fs.root.getdirectory('superseekrit', {create: true}); method overview directoryreadersync createreader () raises (fileexception); fileentrysync getfile (in domstring path, in optional flags options) raises (fileexception); directoryentrysync getdirectory (in domstring path, in optional flags options) raises (fileexception); void removerecursively () raises (fileexception); methods createreader() creates a new directoryreadersync to read entries from this directory. directoryreadersync...
...ile (in domstring path, in optional flags options) raises (fileexception); directoryentrysync getdirectory (in domstring path, in optional flags options) raises (fileexception); void removerecursively () raises (fileexception); methods createreader() creates a new directoryreadersync to read entries from this directory. directoryreadersync createreader ( ) raises (fileexception); returns directoryreadersync represents a directory in a file system. parameter none exceptions this method can raise a fileexception with the following codes: exception description not_found_err the directory does not exist. security_err the browser determined that it was not safe to look up the metadata. [ todo: explain why ] getfile() ...
... description not_found_err the directory does not exist. security_err the browser determined that it was not safe to look up the metadata. [ todo: explain why ] getfile() depending on how you've set the options parameter, the method either creates a file or looks up an existing file. void getfile ( in domstring path, in optional flags options ) raises (fileexception); parameter path either an absolute path or a relative path from the directory to the file to be looked up or created. you cannot create a file whose immediate parent does not exist. create the parent directory first. options an object literal describing the behavior of the method. if the file does not exist, it is created. object literal condition result create: ...
...And 4 more matches

SVGPathSegList - Web APIs
description numberofitemsread only unsigned long the number of items in the list. methods clear() void clears all existing current items from the list, with the result being an empty list. exceptions: a domexception with code no_modification_allowed_err is raised when the list cannot be modified. initialize(in svgpathseg newitem) svgpathseg clears all existing current items from the list and re-initializes the list to hold the single item specified by newitem. if t...
... svgpathseg clears all existing current items from the list and re-initializes the list to hold the single item specified by newitem. if the inserted item is already in a list, it is removed from its previous list before it is inserted into this list. the inserted item is the item itself and not a copy. the return value is the item inserted into the list. exceptions: a domexception with code no_modification_allowed_err is raised when the list cannot be modified. getitem(in unsigned long index) svgpathseg returns the specified item from the list. the returned item is the item itself and not a copy. any changes made to the item are ...
...d_err is raised when the list cannot be modified. getitem(in unsigned long index) svgpathseg returns the specified item from the list. the returned item is the item itself and not a copy. any changes made to the item are immediately reflected in the list. the first item is number 0. exceptions: a domexception with code no_modification_allowed_err is raised when the list cannot be modified. insertitembefore(in svgpathseg newitem, in unsigned long index) svgpathseg inserts a new item into the list at the specified position. the first item is number 0. ...
...And 4 more matches

Operable - Accessibility
ble to close that window again and return to the main content using the keyboard. this is very important so that keyboard users do not get trapped on specific sections of your apps. 2.1.3 keyboard — all functionality (aaa) this is a further step beyond criterion 2.1.1. to achieve aaa conformance, all functionality should be accessible using keyboard controls — with no exceptions. see ui controls and building keyboard accessibility back in 2.1.4 character key shortcuts (a) added in 2.1 if a single character key shortcut exists, then at least one of the following is true: single character key shortcuts can be turned off, remapped or are only active when the relevant user interface component is in focus. understanding character key shortcuts note:...
...need to be completed within a time limit for security reasons. success criteria how to conform to the criteria practical resource 2.2.1 timing is adjustable (a) for functionality with time limits (e.g. completing a hotel or flight booking often has a time limit), the user should be given controls to allow them to adjust, extend or turn off the time limit. exceptions to this are activities with time limits longer than 20 hours, real time events (e.g. live multiplayer games), and any other activity that requires a time limit and would be invalidated if it were turned off. 2.2.2 pausing, stopping, hiding (a) for moving/blinking content that starts automatically, lasts longer than 5 seconds, and is shown alongside other content, control...
... ui controls for general advice on tabbing to controls. if you need to place elements in an unusual layout, it is better to make sure the source order is sensible, then use css features like positioning to handle the layout. 2.4.4 link purpose (in context) (a) the purpose/destination of a link can be determined from the link text, or from its surroundings (e.g. the surrounding text). exceptions are where the link purpose is ambiguous to all users (see ambiguous to users in general for a useful explanation of this). see meaningful text labels. also note that you should minimize instances where multiple copies of the same text are linked to different places. this can cause problems for screenreader users, who will often bring up a list of the links out of context — several links all...
...And 4 more matches

Shell global objects
if the property is omitted or v is null, don't attribute the source to any dom element. elementattributename if present and not undefined, the name of property of element that holds this code. this is wha...
...he dom element o. if the property is omitted or v is null, don't attribute the source to any dom element. elementattributename if present and not undefined, the name of property of element that holds this code. this is what debugger.source.prototype.elementattributename returns. runoffthreadscript() wait for off-thread compilation to complete. ...
...a negative value (default) means that the execution time is unlimited. if a second argument is provided, it will be invoked when the timer elapses. ...
...And 3 more matches

nsIAccessNode
attribute type description document nsiaccessibledocument the document accessible that this access node resides in. read only. note: renamed from accessibledocument in gecko 2.0 domnode node the dom node this nsiaccessnode is associated with. read only. firstchildnode nsiaccessnode the first nsiaccessnode child. read...
..., for the purposes of caching and referencing this object. read only. native code only! methods getchildnodeat() obsolete since gecko 2.0 (firefox 4 / thunderbird 3.3 / seamonkey 2.1) get the nth child of this node. nsiaccessnode getchildnodeat( in long childnum ); parameters childnum zero-based child index. return value the nth nsiaccessnode child. exceptions thrown ns_error_failure indicates that the access node is unattached from the accessible tree. getcomputedstylecssvalue() retrieve the computed style value as nsidomcssprimitivevalue for the dom node this access node is associated with. note: the meanings of width, height and other size measurements depend on the version of css being used. therefore, for bounds information, it is better ...
....getbounds(). nsidomcssprimitivevalue getcomputedstylecssvalue( in domstring pseudoelt, in domstring propertyname ); parameters pseudoelt the pseudo element to retrieve style for, or empty string for general computed style information for the node. propertyname retrieve the computed style value for this property name. return value the nsidomcssprimitivevalue computed style value. exceptions thrown ns_error_failure indicates that the access node is unattached from the accessible tree. getcomputedstylevalue() retrieve the computed style value for this dom node, if it is a dom element. note: the meanings of width, height and other size measurements depend on the version of css being used. therefore, for bounds information, it is better to use nsiaccessible.getbounds(). domstr...
...And 3 more matches

nsIContentPrefService
the result. if desired, javascript callers can instead provide a function to call upon completion. return value the preference's value is returned; this value may be a string, integer, boolean, or any other value. the result may be null (nsidatatype:vtype_empty) if the preference's value is either null, or undefined (nsidatatype:vtype_void) if there is no saved preference by the specified name. exceptions thrown ns_error_illegal_value if agroup is not a string, nsiuri, or null. or if aname is null or an empty string getprefs() get all preferences and their values for the specified uri. note: prior to gecko 2.0, the site could only be specified by nsiuri. now a string can be used as well. nsipropertybag2 getprefs( in nsivariant agroup ); parameters agroup the group whose p...
... group whose preferences are to be retrieved; this may be specified as either a uri or as a string; in either case, the group consists of all sites matching the hostname portion of the specified uri. specify null to get the preferences from the global preference space; those preferences apply to all sites. return value the result is an nsipropertybag2 containing the preferences and their values. ...
... haspref() determines whether or not a preference exists. note: prior to gecko 2.0, the site could only be specified by nsiuri. now a string can be used as well. ...
...And 3 more matches

Debugger.Object - Firefox Developer Tools
value the promise has been rejected with. if the referent is not a promise, or the promise has not been rejected, throw a typeerror. promiseallocationsite if the referent is a promise, this is the javascript execution stack captured at the time of the promise’s allocation. this can return null if the promise was not created from script. if the referent is not a promise, throw a typeerror exception. promiseresolutionsite if the referent is a promise, this is the javascript execution stack captured at the time of the promise’s resolution. this can return null if the promise was not resolved by calling its resolve or reject resolving functions from script. if the referent is not a promise, throw a typeerror exception. promiseid if the referent is a promise, this is a process-unique iden...
... promisedependentpromises if the referent is a promise, this is an array of debugger.objects referring to the promises directly depending on the referent promise. these are: return values of then() calls on the promise. ...
... of the arguments. once a promise is settled, it will generally notify its dependent promises and forget about them, so this is most useful on pending promises. note that the array only contains the promises that directly depend on the referent promise. it does not contain promises that depend on promises that depend on the referent promise. if the referent is not a promise, throw a typeerror exception. promiselifetime if the referent is a promise, this is the number of milliseconds elapsed since the promise was created. if the referent is not a promise, throw a typeerror exception. promisetimetoresolution if the referent is a promise, this is the number of milliseconds elapsed between when the promise was created and when it was resolved. if the referent hasn’t been resolved or is not ...
...And 3 more matches

RTCPeerConnection.setRemoteDescription() - Web APIs
n the connection). the promise fulfillment handler receives no input parameters. note: the process of changing descriptions actually involves intermediary steps handled by the webrtc layer to ensure that an active connection can be changed without losing the connection if the change does not succeed. see pending and current descriptions in webrtc connectivity for more details on this process. exceptions the following exceptions are reported to the rejection handler for the promise returned by setremotedescription(): invalidaccesserror the content of the description is invalid. invalidstateerror the rtcpeerconnection is closed, or it's in a state which isn't compatible with the specified description's type. for example, if the type is rollback and the signaling state is one of stable, hav...
...rejection handler for the promise returned by setremotedescription(): invalidaccesserror the content of the description is invalid. invalidstateerror the rtcpeerconnection is closed, or it's in a state which isn't compatible with the specified description's type. for example, if the type is rollback and the signaling state is one of stable, have-local-pranswer, or have-remote-pranswer, this exception is thrown, because you can't roll back a connection that's either fully established or is in the final stage of becoming connected. operationerror any errors that occur which don't match the others specifeid here are reported as operationerror. this includes identity validation errors. rtcerror an rtcerror with the errordetail set to sdp-syntax-error is reported if the sdp specified by rtcses...
...nnection to a stable signaling state, then, once the rollback is completed, sets the remote description to the specified offer. this begins a new negotiation session, with the newly-established offer as the starting point. upon starting the new negotiation with the newly-established offer, the local peer is now the callee, even if it was previously the caller. ...
...And 3 more matches

SVGAngle - Web APIs
an svgangle object can be associated with a particular element. the associated element is used to determine which element's content attribute to update if the object reflects an attribute. ...
...d an <angle> with a rad unit. svg_angletype_grad an <angle> with a grad unit. properties unittype the type of the value as specified by one of the svg_angletype_* constants defined on this interface. value the value as a floating point value, in user units. setting this attribute will cause valueinspecifiedunits and valueasstring to be updated automatically to reflect this setting. ...
...t. svg_angletype_grad an <angle> with a grad unit. properties unittype the type of the value as specified by one of the svg_angletype_* constants defined on this interface. value the value as a floating point value, in user units. setting this attribute will cause valueinspecifiedunits and valueasstring to be updated automatically to reflect this setting. ...
...And 3 more matches

SVGLength - Web APIs
svg length interface the svglength interface correspond to the <length> basic data type. an svglength object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown. interface overview also implement none methods void newvaluespecifiedunits(in unsigned short unittype, in float valueinspecifiedunits) void converttospecifiedunits(in unsigned short unittype) properties readonly unsigned short unittype float value float valueinspecifiedunits domstring valueasstring constants svg_lengthtype_unknown = 0 svg_lengthtype_number = 1 svg_lengthtype_percentage = 2 svg_lengthtype_ems = 3 svg_lengthtype_exs ...
... name type description unittype unsigned short the type of the value as specified by one of the svg_lengthtype_* constants defined on this interface. value float the value as a floating point value, in user units. setting this attribute will cause valueinspecifiedunits and valueasstring to be updated automatically to reflect this setting. exceptions on setting: a domexception with code no_modification_allowed_err is raised when the length corresponds to a read only attribute or when the object itself is read only. valueinspecifiedunits float the value as a floating point value, in the units expressed by unittype. setting this attribute will cause value and valueasstring to be updated automatically to reflect this set...
... valueasstring domstring the value as a string value, in the units expressed by unittype. ...
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/loader - Archive of obsolete content
ided in the paths option. if this option is not provided, the loader will use plain path resolution. this feature may also be used to implement specific security constraints. for example, the sdk generates a manifest file at build time representing a dependency graph of all modules used by an add-on. ...
... id add-on debugging requires knowing which objects belong to which add-on. when created with this option, loader will transparently mark all new global objects with the provided v...
...ction(id, requirer) { let requirements = manifest[requirer].requirements; if (id in manifest) return requirements[id]; else throw error('module "' + requirer + '" has no authority to require ' + 'module "' + id + "') } }); thrown exceptions will propagate to the caller of require(). if the function assigned to resolve does not return a string value, an exception will still be thrown as the loader will be unable to resolve the required module's location. id add-on debugging requires knowing which objects belong to which add-on. when created with this option, loader will transparently mark all new global objects with the provided value. all together all of these options can be combined to configure the loader for a specific use case. don't get too exci...
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Web Replay
ll as a diff containing the original contents of all pages of heap and static memory that were modified since the previous snapshot. certain memory regions are excluded from snapshots; these memory regions are allocated with a special api and are used for state that needs to be preserved when rewinding. snapshot data may be stored in memory or on disk. diffs are computed by first setting up an exception handler thread (mac only) very similar to the one used by asm.js. when taking the first snapshot all addressable memory in the process is enumerated and write-protected, and as faults occur a special exception handler thread unprotects the memory, copies its contents and marks it as dirty. when the next snapshot is taken, only the dirty memory is examined for any changes vs. the copy made. thi...
...er the debugger is interacting with the child process the child process is paused at some point in execution, and the contents of the debug objects are only valid until the middleman notifies the child process that it can resume forward execution or must rewind to an earlier snapshot. when the child process pauses again (at a breakpoint, say) the debug objects must be reconstructed. there is an exception to this, for scripts and script source objects; debug objects for these will continue to hold the same referent after resuming or rewinding the replaying process. this is necessary for script breakpoints to work, and is implemented by ensuring that the ordering of creation of scripts and script sources is deterministic (mainly by disabling off thread parsing, which is one of the behavior changes...
...tures should not be too hard. unrecordable executions there are restrictions on the executions that can be recorded. these should all be detectable during recording, so that we don't attempt to replay an execution we know will not match up with the recording. the following executions run into fundamental limits of the approach and cannot be replayed: executions which throw overrecursion js exceptions can't be reliably replayed; overrecursion happens at different times depending on how scripts are compiled, which can vary between recording and replaying. similarly, executions which run out of memory at some point can't be reliably replayed. executions which are stopped at some point by the slow script dialog can't be reliably replayed. keeping track of the exact point where an interrupt oc...
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mozIStorageConnection
es a database connection, allowing all pending asynchronous statements to complete first. void asyncclose( in mozistoragecompletioncallback acallback optional ); parameters acallback optional an optional callback handler to be executed when the connection is successfully closed. that object's mozistoragecompletioncallback.complete() routine will be called once the connection is closed. exceptions thrown ns_error_unexpected thrown if the method was called on a thread other than the one that opened the connection. begintransaction() starts a new transaction deferred transaction. this is the same as calling mozistorageconnection with mozistorageconnection.transaction_deferred. void begintransaction(); parameters none. begintransactionas() this method starts a new transaction o...
...onous and synchronous statement execution. the best way to deal with this is to only execute your statements asynchronously using mozistorageconnection.executeasync(). this method will manage the transactions for you, so you don't have to worry about them. note: the database engine does not support nested transactions, so attempting to start a transaction when one is already active will throw an exception. void begintransactionas( in print32 transactiontype ); parameters transactiontype one of the transaction constants (mozistorageconnection.transaction_deferred, mozistorageconnection.transaction_immediate, mozistorageconnection.transaction_exclusive) clone() clones a database connection, optionally making the new connection read only. note: if your connection is already read-only,...
...s access privileges will be the same as the original connection, regardless of the value you specify for the areadonly parameter. mozistorageconnection clone( in boolean areadonly optional ); parameters areadonly if true, the returned database connection is in read only mode. this is false by default. return value a new mozistorageconnection object representing the cloned connection. ...
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nsIAccessibleHyperLink
boolean isvalid(); obsolete since gecko 1.9 attributes attribute type description anchorcount long the number of anchors within this hyperlink. is normally 1 for anchors. this anchor is, for example, the visible output of the html:a tag. with an image map, reflects the actual areas within the map. read only. note: renamed from anchors in gecko 1.9 exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree. endindex long the end offset of the hyperlink accessible within the parent accessible. the returned value is related to the nsiaccessiblehyperlink interface of the object that owns this hyperlink. read only. note: the link itself is represented by one emb...
...rom the accessible tree. endindex long the end offset of the hyperlink accessible within the parent accessible. the returned value is related to the nsiaccessiblehyperlink interface of the object that owns this hyperlink. read only. note: the link itself is represented by one embedded character within the parent text, so the endindex should be startindex + 1. exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree. selected boolean determines whether the element currently has the focus, for example after returning from the destination page. read only. note: aria links can only be focused if they have the tabindex attribute set. also, state_focused should then be se...
... indicates that the accessible is unattached from the accessible tree. selected boolean determines whether the element currently has the focus, for example after returning from the destination page. read only. note: aria links can only be focused if they have the tabindex attribute set. also, state_focused should then be set on the accessible for this link. ...
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nsIContentViewer
dom document object. hide() void hide(); parameters none. native code only!init initializes the content viewer. ...
...d hide(); parameters none. native code only!init initializes the content viewer. void init( in nsiwidgetptr aparentwidget, [const] in nsintrectref abounds ); parameters aparentwidget missing description abounds missing description loadcomplete() void loadcomplete( in unsigned long astatus ); parameters astatus missing description exceptions thrown missing exception missing description loadstart() void loadstart( in nsisupports adoc ); parameters adoc missing description exceptions thrown missing exception missing description move() void move( in long ax, in long ay ); parameters ax missing description ay missing description open() attaches the content viewer to its dom window and docshell. void open( in n...
...ate, in nsishentry ashentry ); parameters astate a state object that might be useful in attaching the dom window. ashentry the history entry that the content viewer was stored in. the entry must have the docshells for all of the child documents stored in its child shell list. pagehide() void pagehide( in boolean isunload ); parameters isunload missing description exceptions thrown missing exception missing description permitunload() determins whether or not the document wants to prevent unloading by firing beforeunload on the document, and if it does, prompts the user. the result is returned. boolean permitunload( in boolean acallercloseswindow optional ); parameters acallercloseswindow optional indicates that the current caller will close() t...
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nsIControllers
ller controller); nsicontroller removecontrollerat(in unsigned long index); attributes attribute type description commanddispatcher nsidomxulcommanddispatcher obsolete since gecko 1.9 methods appendcontroller() adds a controller to the end of the list. void appendcontroller( in nsicontroller controller ); parameters controller a controller to be added to the list of controllers. exceptions thrown ns_error_out_of_memory getcontrollerat() returns the controller instance at the given position. nsicontroller getcontrollerat( in unsigned long index ); parameters index the position of the wanted controller. return value the controller at the given position. exceptions thrown ns_error_failure the given index is out of range. getcontrollerbyid() returns a controller given by its ...
... getcontrollercount() returns the current number of controllers. unsigned long getcontrollercount(); parameters none. return value the number of controllers currently in the list of controllers. ...
...nd the name of a command, e.g. cmd_copy return value the first controller in the list that supports the given command. getcontrollerid() returns the order of insertion of a controller. unsigned long getcontrollerid( in nsicontroller controller ); parameters controller the controller for which you want to retrieve the insertion index. return value the id in which the controller was inserted. exceptions thrown ns_error_failure the controller is not in the list of controllers. insertcontrollerat() inserts a controller at a specific position in the list of controllers. if the position is out of range, nothing happens. void insertcontrollerat( in unsigned long index, in nsicontroller controller ); parameters index the position within the list where you want the controller to be inserted. c...
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nsICryptoHash
any time after " .. manch("init") .. " is called. this call resets the object. acstring finish( in prbool aascii ); parameters aascii if true then the returned value is a base-64 encoded string. if false, then the returned value is binary data. return value this method returns a hash of the data that was read by this object. this can be either binary data or a base-64 encoded string. exceptions thrown ns_error_not_initialized indicates that init() or initwithstring() has not been called. init() initialize the hashing object. this method may be called multiple times with different algorithm types. note: this method or " .. manch("initwithstring") .. " must be called before any other method on this interface is called. void init( in unsigned long aalgorithm ); parameters ...
...() has not been called. init() initialize the hashing object. this method may be called multiple times with different algorithm types. note: this method or " .. manch("initwithstring") .. " must be called before any other method on this interface is called. void init( in unsigned long aalgorithm ); parameters aalgorithm the hash algorithm to use. must be one of the hash algorithms. exceptions thrown ns_error_invalid_arg indicates that an unsupported algorithm type was passed initwithstring() initialize the hashing object. this method may be called multiple times with different algorithm types. note: this method or " .. manch("init") .. " must be called before any other method on this interface is called. void initwithstring( in acstring aalgorithm ); parameters aalgor...
...type was passed initwithstring() initialize the hashing object. this method may be called multiple times with different algorithm types. note: this method or " .. manch("init") .. " must be called before any other method on this interface is called. void initwithstring( in acstring aalgorithm ); parameters aalgorithm the hash algorithm type to be used as a string, such as "sha256". exceptions thrown ns_error_invalid_arg indicates that an unsupported algorithm type was passed update() adds an array of data to be hashed to the object. see computing the hash of a string for an example of using this method. void update( [const, array, size_is(alen)] in octet adata, in unsigned long alen ); parameters adata a buffer to calculate the hash over. alen the length of the bu...
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nsIDownloadManager
rameters alistener the nsidownloadprogresslistener object to receive status information from the download manager. canceldownload() cancels the download with the specified id if it's currently in-progress. this calls cancel(ns_binding_aborted) on the nsicancelable provided by the download. void canceldownload( in unsigned long aid ); parameters aid the unique id of the download. exceptions thrown ns_error_failure the download is not in progress. cleanup() removes completed, failed, and canceled downloads from the list. also notifies observers of the "download-manager-remove-download" topic with a null subject to allow any download manager consumers to react to the removals. void cleanup(); parameters none. endbatchupdate() obsolete since gecko 1.9.1 (...
...he download datasource to disk. void flush(); parameters none. getdownload() retrieves a download managed by the download manager. this can be one that is in progress, or one that has completed in the past and is stored in the database. nsidownload getdownload( in unsigned long aid ); parameters aid the unique id of the download. return value the download with the specified id. exceptions thrown ns_error_not_available the download is not in the database. onclose() obsolete since gecko 1.9.1 (firefox 3.5 / thunderbird 3.0 / seamonkey 2.0)this feature is obsolete. although it may still work in some browsers, its use is discouraged since it could be removed at any time. try to avoid using it. called when the download manager front end is closed. useful for third party mana...
...rs adownload the download object to display progress for, as returned by getdownload() or adddownload(). aparent the parent, or opener, of the front end. acanceldownloadonclose whether closing the dialog should cancel the download. pausedownload() pauses the specified download. void pausedownload( in unsigned long aid ); parameters aid the unique id of the download to pause. exceptions thrown ns_error_failure the download is not in progress. removedownload() removes the download with the specified id if it is not currently in progress. whereas canceldownload() simply cancels the transfer while retaining information about it, removedownload() removes all knowledge of it. also notifies observers of the "download-manager-remove-download" topic with the download id as the ...
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nsIEffectiveTLDService
given number of additional domain name parts. acstring getbasedomain( in nsiuri auri, [optional] in pruint32 aadditionalparts ); parameters auri the uri to be analyzed. aadditionalparts the number of domain name parts to be returned in addition to the public suffix. return value an acstring containing the base domain (public suffix plus the requested number of additional parts). exceptions thrown ns_error_invalid_arg this exception is thrown if the hostname in auri is empty. ns_error_insufficient_domain_levels this exception is thrown if there were insufficient subdomain levels in the hostname to satisfy the requested aadditionalparts value. ns_error_host_is_ip_address this exception is thrown if auri is a numeric ipv4 or ipv6 address. ns_error_unexpected or other error ...
...s not the case. acstring getbasedomainfromhost( in autf8string ahost, in pruint32 aadditionalparts optional ); parameters ahost the host string to be analyzed. aadditionalparts optional the number of domain name parts to be returned in addition to the public suffix. return value an acstring containing the base domain (public suffix plus the requested number of additional parts). ...
...( in autf8string ahost, in pruint32 aadditionalparts optional ); parameters ahost the host string to be analyzed. aadditionalparts optional the number of domain name parts to be returned in addition to the public suffix. return value an acstring containing the base domain (public suffix plus the requested number of additional parts). exceptions thrown ns_error_invalid_arg this exception is thrown if ahost is empty. ns_error_unexpected this exception originates in the normalize() method in nsiidnservice and is thrown when ahost contains characters disallowed in uris. ns_error_insufficient_domain_levels this exception is thrown if there were insufficient subdomain levels in the hostname to satisfy the requested aadditionalparts value. ns_error_host_is_ip_address this excepti...
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nsIIOService
y and according to spec (see rfc 3986). note: most url parsing is done via nsiuri, and in fact the scheme can also be extracted from a url string via nsiuri. this method is provided purely as an optimization. acstring extractscheme( in autf8string urlstring ); parameters urlstring the string for the url to extract the scheme from. return value a string corresponding to the scheme. exceptions thrown ns_error_malformed_uri if url string is not of the right form. getprotocolflags() returns the protocol flags for a given scheme. unsigned long getprotocolflags( in string ascheme ); parameters ascheme the scheme for which to get the protocol flags. return value the value of the protocolflags attribute for the corresponding nsiprotocolhandler. getprotocolhandler() retu...
...loadingnode, so when aloadingnode is passed this can be left as null. however for loads where aloadingnode is null this argument must be passed. for example for loads from a webworker, pass the principal of that worker. for loads from an addon or from internal browser features, pass the system principal. this principal should almost always be the system principal if aloadingnode is null. the only exception to this is for loads from webworkers since they don't have any nodes to be passed as aloadingnode. please note, aloadingprincipal is *not* the principal of the resource being loaded. but rather the principal of the context where the resource will be used. atriggeringprincipal the triggeringprincipal of the load. the triggeringprincipal is the principal of the resource that caused this particula...
...oadingnode, so when aloadingnode is passed this can be left as null. however for loads where aloadingnode is null this argument must be passed. for example for loads from a webworker, pass the principal of that worker. for loads from an addon or from internal browser features, pass the system principal. this principal should almost always be the system principal if aloadingnode is null. the only exception to this is for loads from webworkers since they don't have any nodes to be passed as aloadingnode. please note, aloadingprincipal is *not* the principal of the resource being loaded. but rather the principal of the context here the resource will be used. atriggeringprincipal the triggeringprincipal of the load. the triggeringprincipal is the ...
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nsILivemarkService
his method retrieves the uri of the syndication feed associated with a livemark container. nsiuri getfeeduri( in long long container ); parameters container the folder id of a livemark container. return value a nsiuri representing the uri of the feed; if the livemark container doesn't have a valid feed uri, null will be returned or the nsiuri object returned will be the empty string. exceptions thrown ns_error_invalid_arg if the folder id isn't known or identifies a folder that isn't a livemark container. ns_error_malformed_uri if the site uri annotation has somehow been corrupted (and can't be turned into an nsiuri) getlivemarkidforfeeduri() determines whether the feed uri is a currently registered livemark. long long getlivemarkidforfeeduri( in nsiuri afeeduri ); parame...
...for. return value the id of the livemark. getsiteuri() this method retrieves the uri of the website associated with a livemark container. nsiuri getsiteuri( in long long container ); parameters container the folder id of a livemark container. return value a nsiuri representing the uri of the website; if the livemark container doesn't have a valid site uri, null will be returned. exceptions thrown ns_error_invalid_arg if the folder id isn't known or identifies a folder that isn't a livemark container. ns_error_malformed_uri if the site uri annotation has somehow been corrupted (and can't be turned into an nsiuri) islivemark() this method determines whether the folder with the given folder id identifies a livemark container. boolean islivemark( in long long folder ); p...
...or_malformed_uri if the site uri annotation has somehow been corrupted (and can't be turned into an nsiuri) islivemark() this method determines whether the folder with the given folder id identifies a livemark container. boolean islivemark( in long long folder ); parameters folder a folder id. return value true if the given folder is a livemark folder, otherwise it returns false. exceptions thrown ns_error_invalid_arg if the folder id isn't known. reloadalllivemarks() this method reloads all livemark subscriptions, whether or not they have expired. void reloadalllivemarks(); parameters none. reloadlivemarkfolder() this method reloads the livemark with this folder id, whether or not it's expired. void reloadlivemarkfolder( in long long folderid ); parameters fol...
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nsINavHistoryContainerResultNode
read only. childrenreadonly boolean false if the node's list of children can be modified (by adding or removing children, or rearranging them), or true if the user interface should not allow the list of children to be altered. read-only. this is false for bookmark folder nodes unless the setfolderreadonly() method has been called to specifically make the folder read-o...
... and day groupings, doing this has no performance cost since the children have already been computed. for queries and bookmark folders, however, being open means they must keep themselves up-to-date by listening for updates and re-querying as needed. dynamiccontainertype autf8string a string representing the dynamic container api service responsible for this container. accessing this throws an exception if the node isn't a dynamic container. read only. haschildren boolean indicates whether or not the node can have children, and may be used whether the container is open or closed. when the container is closed, the result is an exact answer if the node can be populated easily (for example, for bookmark folders). if it can't be populated easily (for complex history queries, for example), the resu...
...meters auristring the uri attribute value to match on. atime the time attribute to match on. aitemid the item id to match on. arecursive if true, the search will recurse through all child containers of the current container; if false, only direct children of the container are searched. return value an nsinavhistoryresultnode of a node matching the specified details or null if no match is found. ...
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Component; nsIPrefBranch
specific preference. this will, in effect, reset the value to the default value. if no default value exists the preference will cease to exist. note: this method does nothing if the prefbranch it is called on is a default branch. void clearuserpref( in string aprefname ); parameters aprefname the preference to be cleared. remarks note: prior to gecko 6.0, this method would throw an exception if there was no user value set for the specified preference. now, this method never throws. instead, it simply does nothing. deletebranch() called to remove all of the preferences referenced by this branch. note: this method can be called on either a default or user branch but, in effect, always operates on both. void deletebranch( in string astartingat ); parameters astartingat the ...
... preferences referenced by this branch. getboolpref() called to get the state of an individual boolean preference. boolean getboolpref( in string aprefname, [optional] in boolean adefaultvalue ); parameters aprefname the boolean preference to get the state of. adefaultvalue requires gecko 54 optional - a default value to use if the preference does not exist (instead of throwing an exception). return value the value of the requested boolean preference. getcharpref() called to get the state of an individual string preference. string getcharpref( in string aprefname, [optional] in string adefaultvalue ); parameters aprefname the string preference to retrieve. adefaultvalue requires gecko 54 optional - a default value to use if the preference does not exist (instead of...
...alue the value of the requested boolean preference. getcharpref() called to get the state of an individual string preference. string getcharpref( in string aprefname, [optional] in string adefaultvalue ); parameters aprefname the string preference to retrieve. adefaultvalue requires gecko 54 optional - a default value to use if the preference does not exist (instead of throwing an exception). return value returns string - the value of the requested string preference. getstringpref() requires gecko 58 (firefox 58 / thunderbird 58 / seamonkey 2.55) called to get the state of an individual utf-8 string preference. utf8string getstringpref( in string aprefname, [optional] in utf8string adefaultvalue ); parameters aprefname the string preference to retrieve. ...
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nsIPrincipal
inimum is computed. constant value description enable_denied 1 enable_unknown 2 enable_with_user_permission 3 enable_granted 4 methods native code only!canenablecapability short canenablecapability( in string capability ); parameters capability missing description return value missing description exceptions thrown missing exception missing description checkmayload() checks whether this principal is allowed to load the network resource located at the given uri under the same-origin policy. this means that codebase principals are only allowed to load resources from the same domain, the system principal is allowed to load anything, and null principals are not allowed to load anything. note...
...nction throws ns_error_dom_bad_uri. note: other policies might override this, such as the access-control specification. note: the 'domain' attribute has no effect on the behaviour of this function. void checkmayload( in nsiuri uri, in boolean report ); parameters uri missing description report if true, will report a warning to the console service if the load is not allowed. exceptions thrown ns_error_dom_bad_uri the load is not permitted. native code only!disablecapability void disablecapability( in string capability, inout voidptr annotation ); parameters capability missing description annotation missing description native code only!enablecapability void enablecapability( in string capability, inout voidptr annotation ); parameters ...
... space-delineated list of capabilities which are explicitly denied by a preference. istrusted true if the certificate is a codebase trusted one. ...
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nsIURI
he rules of rfc3986. the result is strictly ascii. read only. hasref boolean returns if there is a reference portion (the part after the "#") of the uri. host autf8string the host is the internet domain name to which this uri refers. it could be an ipv4 (or ipv6) address literal. if supported, it could be a non-ascii internationalized domain name. ...
...about:blank) note: characters are not escaped. origincharset acstring the charset of the document from which this uri originated. an empty value implies utf-8. ...
...inated. an empty value implies utf-8. if this value is something other than utf-8 then the uri components (for example spec, prepath, username, and so on) are all fully url-escaped. otherwise, the uri components may contain unescaped multibyte utf-8 characters. read only. password autf8string the optional password, assuming the prehost consists of "username:password". exceptions thrown ns_error_failure if password is not applicable to the uri scheme (e.g. about:blank) note: some characters may be escaped. path autf8string the path, typically including at least a leading '/' (but may also be empty, depending on the protocol). note: some characters may be escaped. port long the uri's port. a port va...
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CSSPrimitiveValue - Web APIs
e object only occurs in a context of a css property. conversions are allowed between absolute values (from millimeters to centimeters, from degrees to radians, and so on) but not between relative values. (for example, a pixel value cannot be converted to a centimeter value.) percentage values can't be converted since they are relative to the parent value (or another property value). there is one exception for color percentage values: since a color percentage value is relative to the range 0-255, a color percentage value can be converted to a number (see also the rgbcolor interface). <div id="interfacediagram" style="display: inline-block; position: relative; width: 100%; padding-bottom: 11.666666666666666%; vertical-align: middle; overflow: hidden;"><svg style="display: inline-block; position...
... css_unknown the value is not a recognized css2 value. the value can only be obtained by using the csstext attribute. css_uri the value is a <uri>. the value can be obtained by using the getstringvalue() method. methods cssprimitivevalue.getcountervalue() this method is used to get the counter value. if this css value doesn't contain a counter value, a domexception is raised. modification to the corresponding style property can be achieved using the counter interface. cssprimitivevalue.getfloatvalue() this method is used to get a float value in a specified unit. if this css value doesn't contain a float value or can't be converted into the specified unit, a domexception is raised. cssprimitivevalue.getrgbcolorvalue() this method is used to get the rgb c...
... be achieved using the counter interface. cssprimitivevalue.getfloatvalue() this method is used to get a float value in a specified unit. if this css value doesn't contain a float value or can't be converted into the specified unit, a domexception is raised. cssprimitivevalue.getrgbcolorvalue() this method is used to get the rgb color. if this css value doesn't contain a rgb color value, a domexception is raised. modification to the corresponding style property can be achieved using the rgbcolor interface. cssprimitivevalue.getrectvalue() this method is used to get the rect value. if this css value doesn't contain a rect value, a domexception is raised. modification to the corresponding style property can be achieved using the rect interface. cssprimitivevalue.getstringvalue() this method i...
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FileEntrySync - Web APIs
this document was last updated on march 2, 2012 and follows the w3c specifications (working draft) drafted on april 19, 2011. this specification is more or less abandoned as it didn't get significant traction among browser makers. basic concepts to write content to file, create a filewriter object by calling createwriter(). ...
...12 and follows the w3c specifications (working draft) drafted on april 19, 2011. this specification is more or less abandoned as it didn't get significant traction among browser makers. basic concepts to write content to file, create a filewriter object by calling createwriter(). method overview filewritersync createwriter () raises (fileexception); file file () raises (fileexception); methods createwriter() creates a new filewriter associated with the file that the fileentry represents. void createwriter ( ) raises (fileexception); parameter none. returns filewritersync exceptions this method can raise a fileexception with the following codes: exception description not_found_err the file does not exist. invalid_state_err ...
... invalid_state_err the file is no longer valid for some reason other than it having been deleted. ...
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HTMLTableElement - Web APIs
lignment-baseline="middle">htmltableelement</text></a></svg></div> a:hover text { fill: #0095dd; pointer-events: all;} properties inherits properties from its parent, htmlelement. htmltableelement.caption is a htmltablecaptionelement representing the first <caption> that is a child of the element, or null if none is found. when set, if the object doesn't represent a <caption>, a domexception with the hierarchyrequesterror name is thrown. if a correct object is given, it is inserted in the tree as the first child of this element and the first <caption> that is a child of this element is removed from the tree, if any. htmltableelement.thead is a htmltablesectionelement representing the first <thead> that is a child of the element, or null if none is found. when set, if the object doe...
... name is thrown. if a correct object is given, it is inserted in the tree as the first child of this element and the first <caption> that is a child of this element is removed from the tree, if any. htmltableelement.thead is a htmltablesectionelement representing the first <thead> that is a child of the element, or null if none is found. when set, if the object doesn't represent a <thead>, a domexception with the hierarchyrequesterror name is thrown. if a correct object is given, it is inserted in the tree immediately before the first element that is neither a <caption>, nor a <colgroup>, or as the last child if there is no such element, and the first <thead> that is a child of this element is removed from the tree, if any. htmltableelement.tfoot is a htmltablesectionelement representing the fi...
...first element that is neither a <caption>, nor a <colgroup>, or as the last child if there is no such element, and the first <thead> that is a child of this element is removed from the tree, if any. htmltableelement.tfoot is a htmltablesectionelement representing the first <tfoot> that is a child of the element, or null if none is found. when set, if the object doesn't represent a <tfoot>, a domexception with the hierarchyrequesterror name is thrown. if a correct object is given, it is inserted in the tree immediately before the first element that is neither a <caption>, a <colgroup>, nor a <thead>, or as the last child if there is no such element, and the first <tfoot> that is a child of this element is removed from the tree, if any. htmltableelement.rowsread only returns a live htmlcollectio...
...And 2 more matches

Feature-Policy - HTTP
t is allowed to gather information about the amount of light in the environment around the device through the ambientlightsensor interface. autoplay controls whether the current document is allowed to autoplay media requested through the htmlmediaelement interface. when this policy is disabled and there were no user gestures, the promise returned by htmlmediaelement.play() will reject with a domexception. the autoplay attribute on <audio> and <video> elements will be ignored. battery controls whether the use of the battery status api is allowed. when this policy is disabled, the promise returned by navigator.getbattery() will reject with a notallowederror domexception. camera controls whether the current document is allowed to use video input devices. when this policy is disabled, the promise...
... display-capture controls whether or not the current document is permitted to use the getdisplaymedia() method to capture screen contents. ...
...ethod to capture screen contents. when this policy is disabled, the promise returned by getdisplaymedia() will reject with a notallowederror if permission is not obtained to capture the display's contents. document-domain controls whether the current document is allowed to set document.domain. when this policy is disabled, attempting to set document.domain will fail and cause a securityerror domexception to be be thrown. encrypted-media controls whether the current document is allowed to use the encrypted media extensions api (eme). when this policy is disabled, the promise returned by navigator.requestmediakeysystemaccess() will reject with a domexception. execution-while-not-rendered controls whether tasks should execute in frames while they're not being rendered (e.g. if an iframe is hidde...
...And 2 more matches

Index - HTTP
r, reference, response header, header the content-range response http header indicates where in a full body message a partial message belongs. 28 content-security-policy csp, http, reference, security, header the http content-security-policy response header allows web site administrators to control resources the user agent is allowed to load for a given page. with a few exceptions, policies mostly involve specifying server origins and script endpoints. this helps guard against cross-site scripting attacks (xss). 29 csp: base-uri csp, directive, document directive, http, security the http content-security-policy base-uri directive restricts the urls which can be used in a document's <base> element. if this value is absent, then any uri is allowed. if t...
...ature-policy: autoplay directive, feature policy, feature-policy, http, reference, autoplay the http feature-policy header autoplay directive controls whether the current document is allowed to autoplay media requested through the htmlmediaelement interface. when this policy is enabled and there were no user gestures, the promise returned by htmlmediaelement.play() will reject with a domexception. the autoplay attribute on <audio> and <video> elements will be ignored. 65 feature-policy: camera directive, feature policy, feature-policy, http, reference, camera the http feature-policy header camera directive controls whether the current document is allowed to use video input devices. when this policy is enabled, the promise returned by mediadevices.getusermedia() will r...
...wederror. 66 feature-policy: encrypted-media directive, eme, feature policy, feature-policy, http, reference the http feature-policy header encrypted-media directive controls whether the current document is allowed to use the encrypted media extensions api (eme). when this policy is enabled, the promise returned by navigator.requestmediakeysystemaccess() will reject with a domexception. 67 feature-policy: fullscreen feature policy, feature-policy, http, fullscreen, header the http feature-policy header fullscreen directive controls whether the current document is allowed to use element.requestfullscreen(). when this policy is enabled, the returned promise rejects with a typeerror. 68 feature-policy: geolocation feature policy, feature-policy...
...And 2 more matches

core/promise - Archive of obsolete content
on on the promise to observe either its fulfillment or rejection. if the promise is rejected and the rejection is not explicitly observed, any derived promises will be implicitly rejected for the same reason. in the add-on sdk we follow commonjs promises/a specification and model a promise as an object with a then method, which can be used to get the eventual return (fulfillment) value or thrown exception (rejection): foo().then(function success(value) { // ... }, function failure(reason) { // ... }); if foo returns a promise that gets fulfilled with the value, success callback (the value handler) will be called with that value. however, if the returned promise gets rejected, the failure callback (the error handler) will be called with the reason of an error. propagation the then method of...
...led with the value, success callback (the value handler) will be called with that value. however, if the returned promise gets rejected, the failure callback (the error handler) will be called with the reason of an error. propagation the then method of a promise returns a new promise that is resolved with the return value of either handler. ...
... if handler returns a promise, bar will "become" that promise. to be more precise it will be resolved with a resolution value of the returned promise, which will appear and feel as if it was that returned promise. ...
... readasync(url).then(function (value) { throw new error("can't bar."); }, function (error) { // we only get here if `readasync` fails. }); to see why this is, consider the parallel between promises and try/catch. we are try-ing to execute readasync(): the error handler represents a catch for readasync(), while the value han...

Preferences - Archive of obsolete content
ollowing: checks whether the current tree has a value for the preference and whether or not the preference is locked. if there's a value of the correct type (for example, getboolvalue() expects a value of type nsiprefbranch.pref_bool), and the preference is not locked, the method returns that value. if there's a value of the wrong type and the preference is not locked, an ns_error_unexpected exception is thrown. if the preference is locked or if there is no value for that preference in the current tree, the get method checks the default tree. if there's a value of the expected type in the default tree, it is returned (with the only exception being that calling getcomplexvalue() with atype parameter specified as nsipreflocalizedstring, described above). otherwise an ns_error_unexpected excep...
... using prefhasuservalue() nsiprefbranch.prefhasuservalue(preference) checks whether the preference has been changed from the default value. if so, it will return true, otherwise false. in particular, when no default value exists for a preference, prefhasuservalue() indicates whether a preference exists. attempting to read a nonexistent preference using one of the get*pref methods will throw an exception. using prefhasuservalue() lets you check if the preference exists before attempting to read it. for example: if (prefs.prefhasuservalue("mypref")) { alert(prefs.getcharpref("mypref")); } note that the getcharpref() call may throw error even if the preference exists, for example if it has a different type. as of firefox 54, you can pass a default value as the second argument to any get*pref ...
...ting to read it. for example: if (prefs.prefhasuservalue("mypref")) { alert(prefs.getcharpref("mypref")); } note that the getcharpref() call may throw error even if the preference exists, for example if it has a different type. as of firefox 54, you can pass a default value as the second argument to any get*pref method. the default value will be returned if the preference doesn't exist - no exception will be thrown. so you could use, for instance: alert(prefs.getcharpref("mypref", "no value stored")); be careful with this technique because prior to firefox 54, the additional (default) value will be ignored and an exception would still be thrown in this case. using preferences in extensions if you're writing your extension for one of the toolkit applications (firefox, thunderbird, nvu), y...
...sion for one of the toolkit applications (firefox, thunderbird, nvu), you should provide default values for your extension's preferences (see above for information on how to do it). it has the following benefits: you don't have to duplicate default values in various parts of your code. the code for reading preferences is simplified, since you don't need to worry about the get methods throwing exceptions. javascript wrappers for preferences system there are a few javascript wrappers to make your life easier: http://mozilla.doslash.org/prefutils chrome://global/content/nsusersettings.js https://wiki.mozilla.org/labs/js_modules how to save preferences to save preferences into the default location: var prefservice = components.classes["@mozilla.org/preferences-service;1"] ...

Venkman Introduction - Archive of obsolete content
seen in figure 2. the following section describes these views and their use within the interface as a whole. getting acquainted with venkman's user interface toolbar the toolbar is located at the top of the debugger. the toolbar contains icons for stop, continue, step over, step into, step out, profile, and pretty print commands. these commands should be self explanatory, with the possible exception of stop, which causes the debugger to stop when the next line of javascript is executed, and the profile button, which can be used to measure execution times for your scripts. when you enable profiling by clicking this button, a green checkmark appears next to the button and profile data for every function is collected, and can be saved by choosing save profile data as... from the profile menu. ...
...ate that the debugger will stop at the next instruction, but doesn't have anywhere to stop yet. this quick stop mode reflects a common scenario in javascript debugging, which is to inspect and debug scripts while they are running, as on a page where elements are moved around dynamically with dhtml. you can also use commands available in the debug menu and from the console to stop at errors or at exceptions. the continue button to the right of the stop button dismisses the stop mode and specifies that scripts should be executed normally, without pausing as each statement is executed. the pretty print button toggles pretty print mode. while in pretty print mode, the contents of the source view will contain the decompiled source text for the selected function. this is the same text you would get fr...
...o close and re-open any objects you had open to see the change. properties that show up in a bold grey font are defined on an object from the prototype chain, and not on the actual object you are inspecting. if you would like to inspect the object's prototype and parent chains, check the "include ecma properties" menu item in the view's context menu. if a property shows up in a bold red font, an exception occurred when venkman tried to read the value. the exception object will appear as the value of the property. icon data type icon data type void (undefined) value null value boolean value string value integer value double value object value function value figure 9. type icons the column pi...
...iew, with the break and fbreak commands. the break command takes a file pattern and line number. any loaded file which matches the file pattern, and contains an executable line at the requested line number will have a breakpoint set. if no loaded files match the file pattern or line number, an error message is printed to the console and the command fails. the fbreak command is identical, with the exception that if no files match the pattern or line, a "future breakpoint" is recorded. the next time a file is loaded that matches the pattern and line, a breakpoint will be set. in this way, fbreak allows one to set breakpoints in files that are not yet loaded, as well as set breakpoints that are triggered when a file is loaded. the interactive session view another basic view in venkman is the actua...

Implementation Status - Archive of obsolete content
292333; 3.4 extension module unsupported 300760; 3.5 mustunderstand module ...
...-range supported 4.4.17 xforms-out-of-range supported 4.4.18 xforms-scroll-first xforms-scroll-last supported 4.4.19 xforms-submit-done supported 4.5 error indications partial we don't support the xforms-version-exception event, yet 4.5.1 xforms-binding-exception supported 4.5.2 xforms-compute-exception supported 4.5.3 xforms-link-error partial not yet generated by load. 333782; 4.5.4 xforms-link-exception supported 4.5.5...
... 4.5.1 xforms-binding-exception supported 4.5.2 xforms-compute-exception supported 4.5.3 xforms-link-error partial not yet generated by load. ...
... 4.5.3 xforms-link-error partial not yet generated by load. ...

Beginning our React todo list - Learn web development
lg"> what needs to be done? ...
... <button type="button" classname="btn toggle-btn" aria-pressed="false"> <span classname="visually-hidden">show </span> <span>completed</span> <span classname="visually-hidden"> tasks</span> </button> </div> <h2 id="list-heading"> 3 tasks remaining </h2> <ul role="list" classname="todo-list stack-large stack-exception" aria-labelledby="list-heading" > <li classname="todo stack-small"> <div classname="c-cb"> <input id="todo-0" type="checkbox" defaultchecked={true} /> <label classname="todo-label" htmlfor="todo-0"> eat </label> </div> <div classname="btn-group"> <button type="button" classname="btn">...
...ss will be hidden from sighted users and still available to screen reader users — this is because these words are not needed by sighted users; they are there to provide more information about what the button does for screenreader users that do not have the extra visual context to help them. further down, you can find our <ul> element: <ul role="list" classname="todo-list stack-large stack-exception" aria-labelledby="list-heading" > the role attribute helps assistive technology explain what kind of element a tag represents. a <ul> is treated like a list by default, but the styles we're about to add will break that functionality. this role will restore the "list" meaning to the <ul> element. if you want to learn more about why this is necessary, you can check out scott o'hara’s article,...
... clip: rect(1px 1px 1px 1px); clip: rect(1px, 1px, 1px, 1px); white-space: nowrap; } [class*="stack"] > * { margin-top: 0; margin-bottom: 0; } .stack-small > * + * { margin-top: 1.25rem; } .stack-large > * + * { margin-top: 2.5rem; } @media screen and (min-width: 550px) { .stack-small > * + * { margin-top: 1.4rem; } .stack-large > * + * { margin-top: 2.8rem; } } .stack-exception { margin-top: 1.2rem; } /* end global styles */ .todoapp { background: #fff; margin: 2rem 0 4rem 0; padding: 1rem; position: relative; box-shadow: 0 2px 4px 0 rgba(0, 0, 0, 0.2), 0 2.5rem 5rem 0 rgba(0, 0, 0, 0.1); } @media screen and (min-width: 550px) { .todoapp { padding: 4rem; } } .todoapp > * { max-width: 50rem; margin-left: auto; margin-right: auto; } .todoapp > fo...

Storage access policy: Block cookies from trackers
oss visits to multiple first parties. specifically, firefox does this by imposing the following restrictions: cookies: block cookie request headers and ignore set-cookie response headers. return an empty string for calls to document.cookie and ignore requests to set cookies via document.cookie. dom storage: localstorage: window.localstorage: read and write attempts throw a securityerror exception. prior to firefox 70: window.localstorage is null. thus, attempts to read and write using this object will throw a typeerror exception. sessionstorage: read and write attempts are permitted. indexeddb: attempting to access the indexeddb factory object throws a securityerror exception. messaging and workers: broadcast channel: attempts to create a new broadcastchannel will throw a security...
... dom cache: calls to cachestorage will always reject with a securityerror. ...
... dom cache: calls to cachestorage will always reject with a securityerror. ...
... dom cache: calls to cachestorage will always reject with a securityerror. ...

NetUtil.jsm
be an nsiinputstream based object. asink the output stream to which to copy the data. this must be an nsioutputstream based object. acallback an optional function that will be called when the copy operation is completed. the callback receives a single parameter: the nsresult status code for the copy operation. return value returns the nsiasyncstreamcopier object that is handling the copy. exceptions thrown this method throws an exception with the message "must have a source and a sink" if either asource or asink is null. example this example writes a string to a file; it comes from the test suite for the netutil module. var file = cc["@mozilla.org/file/directory_service;1"]. getservice(ci.nsiproperties). get("tmpd", ci.nsifile); file.append("test-file.tmp"); file.c...
... may be specified as an nsiuri, nsifile, nsichannel, nsiinputstream or as a string specifying the url to open. acallback a function that will be called when the open operation is completed. the callback receives three parameters: the input stream containing the data, if any (implementing nsiinputstream), an nsresult status code for the open operation, and a reference to the nsirequest object. exceptions thrown this method throws an exception with the message "must have a source and a callback" if either asource or acallback is null. example this example shows the basic code consumers would need to implement to be correct. netutil.asyncfetch(channel, function(ainputstream, aresult) { // check that we had success. if (!components.issuccesscode(aresult)) { // handle error return; ...
...ional] aorigincharset, [optional] abaseuri ); parameters atarget specifies the target of the uri as either a uri string or (starting in gecko 2) as an nsifile. aorigincharset the optional character set for the uri. defaults to utf-8 if not provided. abaseuri the base uri for the spec, specified as an nsiuri. return value returns the nsiuri object representing the specified target. exceptions thrown this method throws an exception with the message "must have a non-null string spec or nsifile object" and result code ns_error_invalid_arg if aspec is null. readinputstreamtostring() reads a given number of bytes from an input stream, returning a string containing those bytes. this works even if some of those bytes are zeros, instead of terminating the string at the first zero byte. s...
...at all and the raw bytes will be returned. replacement a character with which to replace any invalid byte sequences in the input stream. if you don't specify a replacement character, any invalid sequences will result in ns_error_illegal_input being thrown. this option only has effect if charset is as well. return value a string containing the bytes read from the input stream. exceptions thrown ns_error_invalid_arg the specified stream is not an nsiinputstream. ns_base_stream_would_block reading from the specified stream would block the calling thread, and the stream is in non-blocking mode. ns_error_failure there aren't at least acount bytes available to read from the stream. ns_error_illegal_input the input stream has invalid byte sequences, and no replacement charac...

Python binding for NSS
of this are the various callbacks which can be set and their parameters. thus each thread gets it own set of callbacks. many methods/functions provide sane default (keyword) parameters freeing the python programmer from having to specify all parameters yet allowing them to be overriden when necessary. error codes are never returned from methods/functions. python-nss follows the existing python exception mechanism. any error reported by nss/nspr is converted into a python exception and raised. the exact error code, error description, and often contextual error information will be present in the exception object. enumerated constants used in the nss/nspr api's are available in the python module under the exact same name as they appear in the c header files of nss/nspr. convenience functions are ...
...ly shut it down, this is just failsafe. support was added for shutdown callbacks. ...
...ageobjectsigner nss.certusageusercertimport nss.certusageverifyca nss.certusageprotectedobjectsigner nss.certusagestatusresponder nss.certusageanyca nss.ocspmode_failureisverificationfailure nss.ocspmode_failureisnotaverificationfailure internal changes reimplement exception handling nsprerror is now derived from standardexception instead of environmenterror. it was never correct to derive from environmenterror but was difficult to implement a new subclassed exception with it's own attributes, using environmenterror had been expedient. nsprerror now derived from standardexception, provides: errno (numeric error code) st...
...ed test/run_tests to invoke full test suite. fix bug in test/setup_certs.py, hardcoded full path to libnssckbi.so was causing failures on 64-bit systems, just use the libnssckbi.so basename, modutil will find it on the standard search path. doc/examples/cert_dump.py uses new algorithmid class to dump signature algorithm doc/examples/ssl_example.py now can cleanly shutdown nss. exception error messages now include pr error text if available. the following classes were replaced signaturealgorithm replaced by new class algorithmid the following classes were added algorithmid pkcs12decodeitem pkcs12decoder the following class methods were added pk11slot.authenticate() pk11slot.get_disabled_reason() pk...

Components.lastResult
components.lastresult returns the numeric nsresult code that was the result code of the last xpcom method called via xpconnect. introduction generally, components.lastresult is only useful for testing the result of xpcom methods that can return interesting 'success' codes. this is because failure result codes get converted by xpconnect into exceptions that are thrown into the calling javascript method. most interfaces only return one success code -- ns_ok -- so components.lastresult is rarely necessary. in cases where components.lastresult is used, it is best to get it right away after the target call is made and save it in a local variable to test its value rather than doing multiple tests against components.lastresult. this is because many 'components' properties and methods are themselves im...
...var i = foo.bar(); switch (components.lastresult) { case components.results.ns_ok: // ns_ok is good! break; case 5: // do something with 5 here break; case 6: // do something with 6 here break; default: // this was a success code we did not expect. ...
... good! break; case 5: // do something with 5 here break; case 6: // do something with 6 here break; default: // this was a success code we did not expect. bad component! break; } // and so on.... ...
... break; case 6: // do something with 6 here break; default: // this was a success code we did not expect. bad component! break; } // and so on.... ...

Components.utils.reportError
if it is not a javascript error object, the parameter is converted to a string and reported as a new error. this means you can use components.utils.reporterror to report debugging messages to the error console, just like dump() can be used to print messages to the native console. ...
...if it is not a javascript error object, the parameter is converted to a string and reported as a new error. this means you can use components.utils.reporterror to report debugging messages to the error console, just like dump() can be used to print messages to the native console. ...
...e); consoleservice.logstringmessage("my component: " + amessage); } firefox 3: the error console will not display chrome errors by default. to show them, set the preference 'javascript.options.showinconsole' to true, or use nsconsoleservice instead to show a message. ...
...ent: " + amessage); } firefox 3: the error console will not display chrome errors by default. to show them, set the preference 'javascript.options.showinconsole' to true, or use nsconsoleservice instead to show a message. ...

nsIAccessibleEditableText
associatededitor nsieditor returns an editor associated with the accessible. read only. native code only! methods copytext() copies the text range into the clipboard. void copytext( in long startpos, in long endpos ); parameters startpos start offset of the text to be copied into the clipboard. endpos end offset of the text to be copied into the clipboard. ...
...d into the clipboard. exceptions thrown ns_error_failure indicates the text cannot be copied into the clipboard. cuttext() deletes a range of text and copies it to the clipboard. void cuttext( in long startpos, in long endpos ); parameters startpos start offset of the text to be deleted and copied to clipboard. endpos end offset of the text to be copied into the clipboard. exceptions thrown ns_error_failure indicates the text cannot be deleted or copied into the clipboard. deletetext() deletes a range of text. void deletetext( in long startpos, in long endpos ); parameters startpos start offset of the text to be deleted. endpos end offset of the text to be deleted. exceptions thrown ns_error_failure indicates the text cannot be deleted. inserttext...
...arameters startpos start offset of the text to be deleted. endpos end offset of the text to be deleted. exceptions thrown ns_error_failure indicates the text cannot be deleted. inserttext() inserts text at the specified position. void inserttext( in astring text, in long position ); parameters text text to be inserted. position the offset at which to insert the text. exceptions thrown ns_error_failure indicates the text cannot be inserted. pastetext() pastes text from the clipboard. void pastetext( in long position ); parameters position the offset at which to insert the text from the system clipboard into the text represented by this object. exceptions thrown ns_error_failure indicates the text cannot be pasted from the clipboard. setattributes...
...ets font styles, such as italic, bold, and so on. void setattributes( in long startpos, in long endpos, in nsisupports attributes ); parameters startpos the start index of the text whose attributes are modified. endpos the end index of the text whose attributes are modified. attributes the set of attributes that replaces the old list of attributes of the specified text portion. exceptions thrown ns_error_not_implemented always. the method is not implemented. settextcontents() replaces the text represented by this object with the given text. void settextcontents( in astring text ); parameters text the text that will replace the old text. exceptions thrown ns_error_failure indicates the text cannot be replaced. ...

nsIComponentManager
(see also nsifactory.createinstance.) void createinstance( in nscidref aclass, in nsisupports adelegate, in nsiidref aiid, [iid_is(aiid),retval] out nsqiresult result ); parameters aclass the classid of the object instance that is being requested. adelegate the outer object used for aggregation. aiid the interface type to be returned. result the resulting interface pointer. exceptions thrown ns_error_factory_not_registered indicates that the specified class is not registered. createinstancebycontractid() creates an instance of the class specified by contractid. void createinstancebycontractid( in string acontractid, in nsisupports adelegate, in nsiidref aiid, [iid_is(aiid),retval] out nsqiresult result ); parameters acontractid the contractid of the obje...
...by contractid. void createinstancebycontractid( in string acontractid, in nsisupports adelegate, in nsiidref aiid, [iid_is(aiid),retval] out nsqiresult result ); parameters acontractid the contractid of the object instance that is being requested. adelegate the outer object used for aggregation. aiid the interface type to be returned. result the resulting interface pointer. exceptions thrown ns_error_factory_not_registered indicates that the specified class is not registered. getclassobject() returns the factory object for the class specified by classid. void getclassobject( in nscidref aclass, in nsiidref aiid, [iid_is(aiid),retval] out nsqiresult result ); parameters aclass the classid of the factory that is being requested. aiid the interface type to ...
...at the specified class is not registered. getclassobject() returns the factory object for the class specified by classid. void getclassobject( in nscidref aclass, in nsiidref aiid, [iid_is(aiid),retval] out nsqiresult result ); parameters aclass the classid of the factory that is being requested. aiid the interface type to be returned. result the resulting interface pointer. exceptions thrown ns_error_factory_not_registered indicates that the specified class is not registered. getclassobjectbycontractid() returns the factory object for the class specified by contractid. void getclassobjectbycontractid( in string acontractid, in nsiidref aiid, [iid_is(aiid),retval] out nsqiresult result ); parameters acontractid the contractid of the factory that is being re...
...ed. getclassobjectbycontractid() returns the factory object for the class specified by contractid. void getclassobjectbycontractid( in string acontractid, in nsiidref aiid, [iid_is(aiid),retval] out nsqiresult result ); parameters acontractid the contractid of the factory that is being requested. aiid the interface type to be returned. result the resulting interface pointer. exceptions thrown ns_error_factory_not_registered indicates that the specified class is not registered. removebootstrappedmanifestlocation() unregisters the chrome.manifest file previously registered with the addbootstrappedmanifestlocation() method. see addbootstrappedmanifestlocation() for details. void removebootstrappedmanifestlocation( in interface nsilocalfile alocation ); parameters ex...

nsICryptoHMAC
is method may be called any time after init() is called. this call resets the object to its pre-init state. acstring finish( in prbool aascii ); parameters aascii if true then the returned value is a base-64 encoded string. if false, then the returned value is binary data. return value a hash of the data that was read by this object. this can be either binary data or base 64 encoded. exceptions thrown ns_error_not_initialized if init() has not been called. init() initialize the hashing object. this method may be called multiple times with different algorithm types. warning: this approach is not fips compliant. note: this method must be called before any other method on this interface is called. void init( in unsigned long aalgorithm, in nsikeyobject akeyobject ); param...
...ype to be used. this value must be one of the above valid algorithm types. akeyobject object holding a key. to create the key object use for instance: var keyobject = components.classes["@mozilla.org/security/keyobjectfactory;1"] .getservice(components.interfaces.nsikeyobjectfactory) .keyfromstring(components.interfaces.nsikeyobject.hmac, rawkeydata); exceptions thrown ns_error_invalid_arg if an unsupported algorithm type is passed. reset() reinitialize hmac context to be reused with the same settings (the key and hash algorithm) but on different set of data. void reset(); parameters none. update() void update( [const, array, size_is(alen)] in octet adata, in unsigned long alen ); parameters adata a buffer to calculate the hash ...
...rted algorithm type is passed. reset() reinitialize hmac context to be reused with the same settings (the key and hash algorithm) but on different set of data. void reset(); parameters none. update() void update( [const, array, size_is(alen)] in octet adata, in unsigned long alen ); parameters adata a buffer to calculate the hash over. alen the length of the buffer adata. exceptions thrown ns_error_not_initialized if init() has not been called. updatefromstream() calculates and updates a new hash based on a given data stream. void updatefromstream( in nsiinputstream astream, in unsigned long alen ); parameters astream an input stream to read from. alen how much to read from the given astream. passing pr_uint32_max indicates that all data avai...
... if init() has not been called. updatefromstream() calculates and updates a new hash based on a given data stream. void updatefromstream( in nsiinputstream astream, in unsigned long alen ); parameters astream an input stream to read from. alen how much to read from the given astream. passing pr_uint32_max indicates that all data available will be used to update the hash. exceptions thrown ns_error_not_initialized if init() has not been called. ns_error_not_available if the requested amount of data to be calculated into the hash is not available. ...

nsIHttpChannelInternal
ith this load even if normally they would not be. localaddress autf8string the local ip address to which the channel is bound, in the same format produced by pr_netaddrtostring(). this may be either an ipv4 or ipv6 address. note: if network address translation (nat) is in effect, this may not be the same address the remote host thinks it is talking to. ...
...see bug 534698 and bug 526207. read only. proxyinfo nsiproxyinfo get the proxy info in use by the channel. read only. ...
...y time the nsihttpactivityobserver.isactive attribute is false. see bug 534698 and bug 526207. read only. proxyinfo nsiproxyinfo get the proxy info in use by the channel. read only. obsolete since gecko 1.9 remoteaddress autf8string the ip address of the remote host to which this channel is bound, in the same format produced by pr_netaddrtostring(). ...
...see bug 534698 and bug 526207. read only. methods getrequestversion() gets the request's major and minor version numbers. ...

nsIHttpServer
* * @param prefix * the path on the server (beginning and ending with "/") which is to be * handled b...
...th "/") which is to be * handled by handler; this path must not include a query string or hash * component. all requests that start with this prefix will be directed to * the given handler. * @param handler * an object which will handle any requests for the given path, or null to * remove any existing handler; if while the server is running the handler * throws an exception while responding to a request, an http 500 response * will be returned * @throws ns_error_invalid_arg * if path does not begin with a "/" or does not end with a "/" */ void registerprefixhandler(in string prefix, in nsihttprequesthandler handler); /** * registers a custom error page handler. * * @param code * the error code which is to be handled by handler *...
...*/ void registerprefixhandler(in string prefix, in nsihttprequesthandler handler); /** * registers a custom error page handler. * * @param code * the error code which is to be handled by handler * @param handler * an object which will handle any requests which generate the given status * code, or null to remove any existing handler. if the handler throws an * exception during server operation, fallback is to the genericized error * handler (the x00 version), then to 500, using a user-defined error * handler if one exists or the server default handler otherwise. fallback * will never occur from a user-provided handler that throws to the same * handler as provided by the server, e.g. a throwing user 404 falls back to * 400, not a server-...
...n string extension, in string type); /** * sets the handler used to display the contents of a directory if * the directory contains no index page. * * @param handler * an object which will handle any requests for directories which * do not contain index pages, or null to reset to the default * index handler; if while the server is running the handler * throws an exception while responding to a request, an http 500 * response will be returned. an nsifile corresponding to the * directory is available from the metadata object passed to the * handler, under the key "directory". */ void setindexhandler(in nsihttprequesthandler handler); /** represents the locations at which this server is reachable. */ readonly attribute nsihttpserveridentity ...

nsIInputStream
ative code only! unsigned long readsegments(in nswritesegmentfun awriter, in voidptr aclosure, in unsigned long acount); native code only! methods available() determine number of bytes available in the stream. in addition to the number of bytes available in the stream, this method also informs the caller of the current status of the stream. a stream that is closed will throw an exception when this method is called. that enables the caller to know the condition of the stream before attempting to read from it. if a stream is at end-of-file, but not closed, then this method returns 0 bytes available. note: some nsiinputstream implementations automatically close() when end-of-file is reached; others do not. note: this method should not be used to determine the total size of a str...
... a stream, even if the stream corresponds to a local file. moreover, since a stream may make available more than 2^32 bytes of data, this method is incapable of expressing the entire size of the underlying data source. unsigned long available(); parameters none. return value number of bytes currently available in the stream, or pr_uint32_max if the size of the stream exceeds pr_uint32_max. exceptions thrown <other-error> if the stream is closed due to some error condition. ns_base_stream_closed if the stream is closed normally. close() close the stream. this method causes subsequent calls to read() and readsegments() to return 0 bytes read to indicate end-of-file. note: the close method may be called more than once, but subsequent calls are ignored. void close(); parameters non...
...m into a buffer. unsigned long read( in charptr abuf, in unsigned long acount ); parameters abuf the buffer into which the data from the stream is copied. acount the size of the buffer, or the maximum number of bytes to copy from the stream. return value this method returns the number of bytes copied from the stream (may be less than acount). it returns 0 to indicate end-of-file. exceptions thrown <other-error> on failure. ns_base_stream_would_block indicates that reading from the input stream would block the calling thread for indeterminate amount of time. this exception may only be thrown if isnonblocking() returns true. native code only!readsegments this method provides direct access to the stream's internal buffer. note: a nsiinputstream is not required to implement t...
...ck function that may be called once for each buffer segment contained in the stream. see nswritesegmentfun for more details on this function. aclosure a parameter that is passed to awriter each time it is called. acount the maximum number of bytes to read from the stream. return value the number of bytes read from the stream (may be less than acount). it returns 0 to indicate end-of-file. exceptions thrown <other-error> on failure. ns_error_not_implemented indicates that the stream does not have an internal buffer that can be accessed directly. ns_base_stream_would_block indicates that reading from the input stream would block the calling thread for indeterminate amount of time. this exception may only be thrown if isnonblocking() returns true. example consume all data from an in...

nsILocalFile
appendrelativenativepath appends a relative, native character encoding, path to the current path of the nsilocalfile object. void appendrelativenativepath( in acstring relativefilepath ); parameters relativefilepath a native relative path. for security reasons, this cannot contain '..' or cannot start with a directory separator '/'. must be in the native file system character set. exceptions thrown ns_error_file_unrecognized_path indicates that relativefilepath incorrectly begins with a path separator character or otherwise contains invalid characters. appendrelativepath() appends a relative native path to the current path of the nsilocalfile object. void appendrelativepath( in astring relativefilepath ); parameters relativefilepath a native relative path. for securi...
... begins with a path separator character or otherwise contains invalid characters. appendrelativepath() appends a relative native path to the current path of the nsilocalfile object. void appendrelativepath( in astring relativefilepath ); parameters relativefilepath a native relative path. for security reasons, this cannot contain '..' or cannot start with a directory separator '/' . exceptions thrown ns_error_file_unrecognized_path indicates that relativefilepath incorrectly begins with a path separator character or otherwise contains invalid characters. getrelativedescriptor() returns a relative file path in an opaque, cross platform format. it is therefore not a native path. acstring getrelativedescriptor( in nsilocalfile fromfile ); parameters fromfile the file from...
...e afile ); parameters afile the file this becomes equivalent to. initwithnativepath() used to set the full path that this nsilocalfile references. all current settings will be reset. void initwithnativepath( in acstring filepath ); parameters filepath a string that specifies a platform-specific, full path to a file or directory. must be in the native file system character set. exceptions thrown ns_error_file_unrecognized_path indicates that filepath is not an absolute file path or that it contains characters that are invalid for the filesystem. initwithpath() used to set the full path that this nsilocalfile references. all current settings will be reset. void initwithpath( in astring filepath ); parameters filepath a string that specifies a platform-specific, ful...
...nized_path indicates that filepath is not an absolute file path or that it contains characters that are invalid for the filesystem. initwithpath() used to set the full path that this nsilocalfile references. all current settings will be reset. void initwithpath( in astring filepath ); parameters filepath a string that specifies a platform-specific, full path to a file or directory. exceptions thrown ns_error_file_unrecognized_path indicates that filepath is not an absolute file path or that it contains characters that are invalid for the filesystem. launch() requests that the operating system attempt to open this file. void launch(); parameters none. native code only! load returns the result of pr_loadlibrary() on the file. the caller is responsible for calling pr_...

nsIServiceManager
d of the service. unlike createinstance, this will always return the same object each time it is called with the same arguments. void getservice( in nscidref aclass, in nsiidref aiid, [iid_is(aiid),retval] out nsqiresult result ); parameters aclass the classid of the service that is being requested. aiid the interface type to be returned. result the resulting interface pointer. exceptions thrown ns_error_factory_not_registered indicates that the specified class is not registered. getservicebycontractid() this method returns a reference to a particular xpcom service given the contractid of the service. void getservicebycontractid( in string acontractid, in nsiidref aiid, [iid_is(aiid),retval] out nsqiresult result ); parameters acontractid the contractid of the...
...tid() this method returns a reference to a particular xpcom service given the contractid of the service. void getservicebycontractid( in string acontractid, in nsiidref aiid, [iid_is(aiid),retval] out nsqiresult result ); parameters acontractid the contractid of the service that is being requested. aiid the interface type to be returned. result the resulting interface pointer. exceptions thrown ns_error_factory_not_registered indicates that the specified class is not registered. isserviceinstantiated() this method tests whether or not a xpcom service, identified by classid, has been instantiated. boolean isserviceinstantiated( in nscidref aclass, in nsiidref aiid ); parameters aclass the classid of the service that is being tested. aiid the interface type to ...
...class is not registered. isserviceinstantiated() this method tests whether or not a xpcom service, identified by classid, has been instantiated. boolean isserviceinstantiated( in nscidref aclass, in nsiidref aiid ); parameters aclass the classid of the service that is being tested. aiid the interface type to be tested. return value true if the service has already been created. exceptions thrown ns_error_service_not_available indicates that the service hasn't been instantiated. ns_nointerface indicates that the iid given isn't supported. isserviceinstantiatedbycontractid() this method tests whether or not a xpcom service, identified by contractid, has been instantiated. boolean isserviceinstantiatedbycontractid( in string acontractid, in nsiidref aiid ); parameter...
...stantiatedbycontractid() this method tests whether or not a xpcom service, identified by contractid, has been instantiated. boolean isserviceinstantiatedbycontractid( in string acontractid, in nsiidref aiid ); parameters acontractid the contractid of the service that is being tested. aiid the interface type to be tested. return value true if the service has already been created. exceptions thrown ns_error_service_not_available indicates that the service hasn't been instantiated. ns_nointerface indicates that the iid given isn't supported. remarks the service manager depends on the repository to find and instantiate factories to obtain services. because services are instantiated lazily, methods are provided to test whether or not a service has already been instantiated. ...

XPCOM Interface Reference
eporternsicryptohmacnsicryptohashnsicurrentcharsetlistenernsicyclecollectorlistenernsidbchangelistenernsidbfolderinfonsidnslistenernsidnsrecordnsidnsrequestnsidnsservicensidomcanvasrenderingcontext2dnsidomchromewindownsidomclientrectnsidomdesktopnotificationnsidomdesktopnotificationcenternsidomelementnsidomeventnsidomeventgroupnsidomeventlistenernsidomeventtargetnsidomfilensidomfileerrornsidomfileexceptionnsidomfilelistnsidomfilereadernsidomfontfacensidomfontfacelistnsidomgeogeolocationnsidomgeopositionnsidomgeopositionaddressnsidomgeopositioncallbacknsidomgeopositioncoordsnsidomgeopositionerrornsidomgeopositionerrorcallbacknsidomgeopositionoptionsnsidomglobalpropertyinitializernsidomhtmlaudioelementnsidomhtmlformelementnsidomhtmlmediaelementnsidomhtmlsourceelementnsidomhtmltimerangesnsidomjswindow...
...idomnavigatordesktopnotificationnsidomnodensidomofflineresourcelistnsidomorientationeventnsidomparsernsidomprogresseventnsidomserializernsidomsimplegestureeventnsidomstoragensidomstorage2nsidomstorageeventobsoletensidomstorageitemnsidomstoragelistnsidomstoragemanagernsidomstoragewindownsidomuserdatahandlernsidomwindownsidomwindow2nsidomwindowinternalnsidomwindowutilsnsidomxpathevaluatornsidomxpathexceptionnsidomxpathexpressionnsidomxpathresultnsidomxulcontrolelementnsidomxulelementnsidomxullabeledcontrolelementnsidomxulselectcontrolelementnsidomxulselectcontrolitemelementnsidatasignatureverifiernsidebugnsidebug2nsidevicemotionnsidevicemotiondatansidevicemotionlistenernsidialogcreatornsidialogparamblocknsidictionarynsidirindexnsidirindexlistenernsidirindexparsernsidirectoryenumeratornsidirectoryiter...
...sslistenernsidownloadernsidragdrophandlernsidragservicensidragsessionnsidroppedlinkhandlernsidroppedlinkitemnsidynamiccontainernsieditornsieditorboxobjectnsieditordocshellnsieditorimesupportnsieditorloggingnsieditormailsupportnsieditorobservernsieditorspellchecknsieffectivetldservicensienumeratornsienvironmentnsierrorservicensieventlistenerinfonsieventlistenerservicensieventsourcensieventtargetnsiexceptionnsiextensionmanagernsiexternalhelperappservicensiexternalprotocolservicensiexternalurlhandlerservicensiftpchannelnsiftpeventsinknsifactorynsifavicondatacallbacknsifaviconservicensifeednsifeedcontainernsifeedelementbasensifeedentrynsifeedgeneratornsifeedpersonnsifeedprocessornsifeedprogresslistenernsifeedresultnsifeedresultlistenernsifeedtextconstructnsifilensifileinputstreamnsifileoutputstreamnsif...
...inapphelpernsiwintaskbarnsiwindowcreatornsiwindowmediatornsiwindowwatchernsiwindowsregkeynsiwindowsshellservicensiworkernsiworkerfactorynsiworkerglobalscopensiworkermessageeventnsiworkermessageportnsiworkerscopensiwritablepropertybagnsiwritablepropertybag2nsixformsmodelelementnsixformsnsinstanceelementnsixformsnsmodelelementnsixmlhttprequestnsixmlhttprequesteventtargetnsixmlhttprequestuploadnsixpcexceptionnsixpcscriptablensixpconnectnsixsltexceptionnsixsltprocessornsixsltprocessorobsoletensixulappinfonsixulbrowserwindownsixulbuilderlistenernsixulruntimensixulsortservicensixultemplatebuildernsixultemplatequeryprocessornsixultemplateresultnsixulwindownsixmlrpcclientnsixmlrpcfaultnsizipentrynsizipreadernsizipreadercachensizipwriternsmsgfilterfileattribvaluensmsgfolderflagtypensmsgjunkstatusnsmsgkeynsm...

ArrayType
pe[ length] ); parameters type: it represents the type of the elements or variable which is going to be present in an array length optional it denotes the number of entries present in an array or the number of elements that an array should contain. if you don't specify this parameter, the array's length is unspecified. return value a ctype represents the newly declared array type. exceptions thrown typeerror type is not a ctype, or type.size is undefined.if the length is specifed but if it is not a valid one,then it is also thrown rangeerror the size of the resulting array can't be represented as both a size_t and as a javascript number. properties property type description elementtype ctype the data type of the elements in an array type. read...
...type array([n]) string tosource() string tostring() arraytype cdata syntax cdata sized_arraytype(); cdata unsized_arraytype(length); sized_arraytype and unsized_arraytype are arraytype ctype. parameters length the number of entries the array type should be able to contain. only for unsized arraytype. return value a cdata representing the newly allocated array. exceptions thrown typeerror length is not provided for unsized array, or is provided for sized array. arraytype cdata properties property type description length number the length of the array. read only. in addition, each element in the array can be referenced by index using standard bracket notation, such as myarray[index]. properties inherited from cdata ...
...tion, such as myarray[index]. properties inherited from cdata property type description constructor ctype the data type of the cdata object, as a ctype. read only. note: this is never ctypes.void_t or an array type with an unspecified length. value object the javascript equivalent of the cdata object's value. this will throw a typeerror exception if the value can't be converted. arraytype cdata method_overview cdata addressofelement(idx) methods inherited from cdata cdata address() string tosource() string tostring() arraytype cdata methods addressofelement() returns a new cdata object of the appropriate pointer type, whose value points to the specified array element on which th...
...ement() returns a new cdata object of the appropriate pointer type, whose value points to the specified array element on which the method was called. cdata addressofelement( idx ); parameters idx a numeric value indicating the offset into the array of the element just to return a pointer. if this value isn't a valid javascript number that's also a valid index into the array, a typeerror exception is thrown. return value a new cdata object pointing to the specified element. the type of the returned object will be determined by ctypes.pointertype(thearraytype.constructor.elementtype)). see also ctype cdata type conversion ...

Int64
a string, which may consist of an optional minus sign, followed by either a decimal number or "0x" or "0x" followed by a hexadecimal number. the string is then converted into the corresponding 64-bit integer value. you can therefore use a string to represent a 64-bit value that is too large to represent as a 32-bit javascript number. return value a new object representing the specified value. exceptions thrown typeerror the specified value cannot be converted into a 64-bit integer. either it's not a number, string, or 64-bit integer object, or it's a string that is incorrectly formatted or contains a value outside the range that can be represented in 64 bits. this will also be thrown if the source value is a floating-point number that can't be precisely represented as a 64-bit integer. me...
... number hi(a); int64 join(high, low); number lo(a); string tosource(); string tostring([radix]); methods compare() compares two 64-bit integer values. number compare( a, b ); parameters a the first value to compare. b the second value to compare. return value the returned value is: -1 if a < b, 0 if a == b, and 1 if a > b. ...
... if a < b, 0 if a == b, and 1 if a > b. exceptions thrown typeerror one or both of the specified values is not a 64-bit integer (either signed or unsigned). hi() returns the high 32 bits of the specified value. number hi( num ); parameters num the value whose high 32 bits are to be returned. return value the high 32 bits of num are returned. this is essentially num >> 32. exceptions thrown typeerror num is not a 64-bit integer object. lo() returns the low 32 bits of the specified value. number lo( num ); parameters num the int64 value whose low 32 bits are to be returned. return value the low 32 bits of num are returned. this is essentially num & 0xffffffff. exceptions thrown typeerror num is not a 64-bit integer object. join() creates a 64-bit in...
...() creates a 64-bit integer object whose value is constructed using the specified high and low order 32-bit values. int64 join( high, low ); parameters high the high-order 32 bits of the value to create. low the low-order 32 bits of the value to create. return value a new 64-bit integer object comprised of the two values merged together. the returned value is (high << 32) + low. exceptions thrown typeerror one or both of the specified numbers is not a javascript number with an integral value. tosource() this method is for internal debugging use only. warning: do not rely on the value returned by this method, as it's subject to change at any time, depending on the debugging needs of the developers. tostring() returns a string representation of the object's numeric value. ...

StructType
of field descriptors, describing all the entries in the structure. if this isn't specified, the structure is considered opaque and you can't access its contents directly. you can call the resulting type's define() method to assign it a non-opaque type later. see opaque structures for further explanation and an example. return value a ctype object describing the newly created struct data type. exceptions thrown typeerror the name is not a string, or one or more of the fields does not have a defined size. rangeerror the size of the structure, in bytes, cannot be represented both as a size_t and as a javascript number. describing fields the fields array is comprised of field descriptors, one for each field in the structure. each field descriptor contains the field's name and its type, suc...
...ostring() methods define() defines a previously declared opaque type's fields. this lets you convert an opaque structure type into a defined structure type. define( fields ); parameters fields a field specification, as described above. structtype cdata syntax cdata structtype(); structtype is structtype ctype. return value a cdata representing the newly allocated struct. exceptions thrown error fields are not yet defined. structtype cdata properties every struct object has a getter and a setter for each member field of the structure. properties inherited from cdata property type description constructor ctype the data type of the cdata object, as a ctype. read only. note: this is never ctypes.void_t or an array type with an u...
...ember field of the structure. properties inherited from cdata property type description constructor ctype the data type of the cdata object, as a ctype. read only. note: this is never ctypes.void_t or an array type with an unspecified length. value object the javascript equivalent of the cdata object's value. this will throw a typeerror exception if the value can't be converted. structtype cdata method_overview cdata addressoffield(name) methods inherited from cdata cdata address() string tosource() string tostring() structtype cdata methods addressoffield() returns a new cdata object of the appropriate pointer type, whose value points to the specified field of the structure on ...
...ose value points to the specified field of the structure on which the method was called. see working with strings for more information on how to convert strings. cdata addressoffield( name ); parameters name the name of the field whose address is to be returned. return value a new cdata object of the appropriate pointer type, whose value points to the contents of the specified field. exceptions thrown typeerror name is not a javascript string, or doesn't name a member field of the structure. see also ctype cdata type conversion ...

UInt64
a string, which may consist of an optional minus sign, followed by either a decimal number or "0x" or "0x" followed by a hexadecimal number. the string is then converted into the corresponding 64-bit integer value. you can therefore use a string to represent a 64-bit value that is too large to represent as a 32-bit javascript number. return value a new object representing the specified value. exceptions thrown typeerror the specified value cannot be converted into a 64-bit integer. either it's not a number, string, or 64-bit integer object, or it's a string that is incorrectly formatted or contains a value outside the range that can be represented in 64 bits. this will also be thrown if the source value is a floating-point number that can't be precisely represented as a 64-bit integer. me...
... b); number hi(a); uint64 join(high, low); number lo(a); string tosource(); string tostring([radix]); methods compare() compares two 64-bit integer values. number compare( a, b ); parameters a the first value to compare. b the second value to compare. return value the returned value is -1 if a < b, 0 if a == b, and 1 if a > b. ...
...-1 if a < b, 0 if a == b, and 1 if a > b. exceptions thrown typeerror one or both of the specified values is not a 64-bit integer (either signed or unsigned). hi() returns the high 32 bits of the specified value. number hi( num ); parameters num the value whose high 32 bits are to be returned. return value the high 32 bits of num are returned. this is essentially num >> 32. exceptions thrown typeerror num is not a 64-bit integer object. lo() returns the low 32 bits of the specified value. number lo( num ); parameters num the int64 value whose low 32 bits are to be returned. return value the low 32 bits of num are returned. this is essentially num & 0xffffffff. exceptions thrown typeerror num is not a 64-bit integer object. join() creates a 64-bi...
...n() creates a 64-bit integer object with a value constructed using the specified high and low order 32-bit values. uint64 join( high, low ); parameters high the high-order 32 bits of the value to create. low the low-order 32 bits of the value to create. return value a new 64-bit integer object comprised of the two values merged together. the returned value is (high << 32) + low. exceptions thrown typeerror one or both of the specified numbers is not a javascript number with an integral value. tosource() this method is for internal debugging use only. warning: do not rely on the value returned by this method, as it's subject to change at any time, depending on the debugging needs of the developers. tostring() returns a string representation of the object's numeric val...

Element.classList - Web APIs
ll compliance (coverage) for all standard methods and properties of element.prototype.classlist for ie10-ie11 browsers plus nearly compliant behavior for ie 6-9. check it out: // 1. ...
...coverage) for all standard methods and properties of element.prototype.classlist for ie10-ie11 browsers plus nearly compliant behavior for ie 6-9. check it out: // 1. ...
...implement the barebones domtokenlist livelyness polyfill if (typeof domtoken...
...amespace pollution if(!window.domexception) (domexception = function(reason){this.message = reason}).prototype = new error; var wsre = /[\11\12\14\15\40]/, wsindex = 0, checkifvalidclasslistentry = function(o, v) { if (v === "") throw new domexception( "failed to execute '" + o + "' on 'domtokenlist': the token provided must not be empty." ); if((wsindex=v.search(wsre))!==-1) throw new domexception("failed to execute '"+o+"' on 'domtokenlist': " + "the token provided ('"+v[wsindex]+"') contains html space characters, which are not valid in tokens."); } // 2. implement the barebones domtokenlist livelyness polyfill if (typeof domtokenlist !== "function") (function(window){ var document = window.document, object = window.object, hasownprop = object.prototype.hasownproperty; var de...

FileSystemDirectoryEntry - Web APIs
support yesgetdirectory experimentalchrome full support 8edge full support 79firefox full support 50notes full support 50notes notes in firefox, the errorcallback's input parameter is a domexception rather than a fileerror object.ie no support noopera no support nosafari full support 11.1webview android full support ≤37chrome android full support 18firefox android ...
...t 11.1webview android full support ≤37chrome android full support 18firefox android full support 50notes full support 50notes notes in firefox, the errorcallback's input parameter is a domexception rather than a fileerror object.opera android no support nosafari ios full support 11.3samsung internet android full support yesgetfile experimentalchrome full support 8edge full support ...
... full support yesgetfile experimentalchrome full support 8edge full support 79firefox full support 50notes full support 50notes notes in firefox, the errorcallback's input parameter is a domexception rather than a fileerror object.ie no support noopera no support nosafari full support 11.1webview android full support ≤37chrome android full support 18firefox android ...
...t 11.1webview android full support ≤37chrome android full support 18firefox android full support 50notes full support 50notes notes in firefox, the errorcallback's input parameter is a domexception rather than a fileerror object.opera android no support nosafari ios full support 11.3samsung internet android full support yesremoverecursively deprecatednon-standardchrome full support 8edge full suppo...

HTMLInputElement - Web APIs
string: returns / sets the element's max attribute, containing the maximum (numeric or date-time) value for this item, which must not be less than its minimum (min attribute) value. maxlength long: returns / sets the element's maxlength attribute, containing the maximum number of characters (in unicode code points) that the value can have. (if you set this to a negative number, an exception will be thrown.) min string: returns / sets the element's min attribute, containing the minimum (numeric or date-time) value for this item, which must not be greater than its maximum (max attribute) value. minlength long: returns / sets the element's minlength attribute, containing the minimum number of characters (in unicode code points) that the value can have. (if you s...
... string: returns / sets the element's min attribute, containing the minimum (numeric or date-time) value for this item, which must not be greater than its maximum (max attribute) value. minlength long: returns / sets the element's minlength attribute, containing the minimum number of characters (in unicode code points) that the value can have. (if you set this to a negative number, an exception will be thrown.) pattern string: returns / sets the element's pattern attribute, containing a regular expression that the control's value is checked against. use the title attribute to describe the pattern to help the user. this attribute applies when the value of the type attribute is text, search, tel, url or email; otherwise it is ignored. placeholder string: returns / ...
... constraints. reportvalidity() runs the checkvalidity() method, and if it returns false (for an invalid input or no pattern attribute provided), then it reports to the user that the input is invalid in the same manner as if you submitted a form. htmlinputelement.stepdown() decrements the value by (step * n), where n defaults to 1 if not specified. ...
... htmlinputelement.mozgetfilenamearray() returns an array of all the file names from the input. ...

IDBTransactionSync - Web APIs
onable. it may however be reintroduced in the future if there is enough demand from web developers. the idbtransactionsync interface of the indexeddb api provides a synchronous transaction on a database. when an application creates an idbtransactionsync object, it blocks until the browser is able to reserve the require database objects. method overview void abort() raises (idbdatabaseexception); void commit() raises (idbdatabaseexception); idbobjectstoresync objectstore(in domstring name) raises (idbdatabaseexception); attributes attribute type description db idbdatabasesync the database connection that this transaction is associated with. static boolean if true, this transaction is static; if false, this trans...
...tic boolean if true, this transaction is static; if false, this transaction is dynamic. methods abort() call this method to signal a need to cancel the effects of the operations performed by this transaction. when this method is called, the browser ignores all the changes performed to the objects of this database since this transaction was created. void abort( ) raises (idbdatabaseexception); exceptions this method can raise an idbdatabaseexception with the following code: non_transient_err if this transaction has already been committed or aborted. commit() call this method to signal that the transaction has completed normally and satisfactorily. when this method is called, the browser durably stores all the changes performed to the objects of the database since this trans...
...ception with the following code: non_transient_err if this transaction has already been committed or aborted. commit() call this method to signal that the transaction has completed normally and satisfactorily. when this method is called, the browser durably stores all the changes performed to the objects of the database since this transaction was created. void commit( ) raises (idbdatabaseexception); exceptions this method can raise an idbdatabaseexception with the following codes: non_transient_err if this transaction has already been committed or aborted. recoverable_err if this transaction's scope is dynamic, and the browser cannot commit all of the changes due to another transaction. objectstore() returns an object store that has already been added to the scope of this trans...
...codes: non_transient_err if this transaction has already been committed or aborted. recoverable_err if this transaction's scope is dynamic, and the browser cannot commit all of the changes due to another transaction. objectstore() returns an object store that has already been added to the scope of this transaction. idbobjectstoresync objectstore( in domstring name ) raises (idbdatabaseexception); parameters name the name of the requested object store. returns idbobjectstoresync an object for accessing the requested object store. exceptions the method can raise an idbdatabaseexception with the following code: not_found_err if the requested object store is not in this transaction's scope. ...

PaymentResponse.retry() - Web APIs
f the user chose to pay by credit card using the basic-card payment method, this is a basiccarderrors object. shippingaddress optional an addresserrors object which contains error messages for any of the fields in the shipping address that failed validation. return value a promise which is resolved when the payment is successfully completed. the promise is rejected with an appropriate exception value if the payment fails again. typically you will use this by calling show(), then entering a loop or recursive function that checks the paymentresponse for errors or other reasons to retry the payment request. if a retry is needed, the loop calls retry(), then loops back to check the response when it comes in. the loop exits only when the user either cancels the payment request or the reques...
...ith a value of "fail" to indicate failure. if the response's data is valid and acceptable, call complete("success") to finalize the payment and proces it. if show() is rejected, the payment request failed, usually because either there's already one being processed, because the user agent doesn't support any of the specified payment methods, or because of a security issue. see the list of exceptions for show() for further details. call complete("fail") to close the payment request. async function handlepayment() { const payrequest = new paymentrequest(methoddata, details, options); try { let payresponse = await payrequest.show(); while (payresponse has errors) { /* let the user edit the payment information, wait until they submit */ await response.retry(...
...} async function dopaymentrequest() { const request = new paymentrequest(methoddata, details, options); const response = await request.show(); await recursivevalidate(request, response); await response.complete("success"); } // keep validating until the data looks good! async function re...
...ils, options); try { let payresponse = await payrequest.show(); while (payresponse has errors) { /* let the user edit the payment information, wait until they submit */ await response.retry(); } await payresponse.complete("success"); } catch(err) { /* handle the exception */ } } examples try { await paymentrequest.retry(errorfields); } catch (domexception err) { ... } async function dopaymentrequest() { const request = new paymentrequest(methoddata, details, options); const response = await request.show(); await recursivevalidate(request, response); await response.complete("success"); } // keep validating until the data looks good! async function recursivevalidate(request, response) { const promisestofixthings = []; const errors = aw...

Web APIs
clients clipboard clipboardevent clipboarditem closeevent comment compositionevent constantsourcenode constrainboolean constraindomstring constraindouble constrainulong contentindex contentindexevent convolvernode countqueuingstrategy crashreportbody credential credentialscontainer crypto cryptokey cryptokeypair customelementregistry customevent d domconfiguration domerror domexception domhighrestimestamp domimplementation domimplementationlist domlocator dommatrix dommatrixreadonly domobject domparser dompoint dompointinit dompointreadonly domquad domrect domrectreadonly domstring domstringlist domstringmap domtimestamp domtokenlist domuserdata datatransfer datatransferitem datatransferitemlist dedicatedworkerglobalscope delaynode deprecationreportbody deviceligh...
...xt_texture_compression_bptc ext_texture_compression_rgtc ext_texture_filter_anisotropic eckeygenparams eckeyimportparams ecdhkeyderiveparams ecdsaparams effecttiming element elementcssinlinestyle elementtraversal errorevent event eventlistener eventsource eventtarget extendableevent extendablemessageevent f featurepolicy federatedcredential fetchevent file fileentrysync fileerror fileexception filelist filereader filereadersync filerequest filesystem filesystemdirectoryentry filesystemdirectoryreader filesystementry filesystementrysync filesystemfileentry filesystemflags filesystemsync focusevent fontface fontfaceset fontfacesetloadevent formdata formdataentryvalue formdataevent fullscreenoptions g gainnode gamepad gamepadbutton gamepadevent gamepadhapticactu...
...nt htmltablecellelement htmltablecolelement htmltableelement htmltablerowelement htmltablesectionelement htmltemplateelement htmltextareaelement htmltimeelement htmltitleelement htmltrackelement htmlulistelement htmlunknownelement htmlvideoelement hashchangeevent headers history hkdfparams hmacimportparams hmackeygenparams i idbcursor idbcursorsync idbcursorwithvalue idbdatabase idbdatabaseexception idbdatabasesync idbenvironment idbenvironmentsync idbfactory idbfactorysync idbindex idbindexsync idbkeyrange idblocaleawarekeyrange idbmutablefile idbobjectstore idbobjectstoresync idbopendbrequest idbrequest idbtransaction idbtransactionsync idbversionchangeevent idbversionchangerequest iirfilternode idledeadline imagebitmap imagebitmaprenderingcontext imagecaptu...
...exarrayobject webkitcssmatrix websocket wheelevent window windowclient windoweventhandlers windoworworkerglobalscope worker workerglobalscope workerlocation workernavigator worklet writablestream writablestreamdefaultcontroller writablestreamdefaultwriter x xdomainrequest xmldocument xmlhttprequest xmlhttprequesteventtarget xmlhttprequestresponsetype xmlserializer xpathevaluator xpathexception xpathexpression xpathnsresolver xpathresult xrboundedreferencespace xrenvironmentblendmode xreye xrframe xrframerequestcallback xrhandedness xrinputsource xrinputsourcearray xrinputsourceevent xrinputsourceeventinit xrinputsourceschangeevent xrinputsourceschangeeventinit xrpermissiondescriptor xrpermissionstatus xrpose xrreferencespace xrreferencespaceevent xrreferencespaceeventinit xrreference...

HTTP Index - HTTP
ader, header the content-range response http header indicates where in a full body message a partial message belongs. 76 content-security-policy csp, content security policy, http, reference, security, header the http content-security-policy response header allows web site administrators to control resources the user agent is allowed to load for a given page. with a few exceptions, policies mostly involve specifying server origins and script endpoints. this helps guard against cross-site scripting attacks (xss). 77 csp: base-uri csp, directive, document directive, http, security the http content-security-policy base-uri directive restricts the urls which can be used in a document's <base> element. if this value is absent, then any uri is allowed. if t...
...'s contents. 129 feature-policy: document-domain directive, experimental, feature policy, feature-policy, http, reference, document-domain, header the http feature-policy header document-domain directive controls whether the current document is allowed to set document.domain. when this policy is enabled, attempting to set document.domain will fail and cause a securityerror domexception to be be thrown. 130 feature-policy: encrypted-media directive, eme, feature policy, feature-policy, http, reference the http feature-policy header encrypted-media directive controls whether the current document is allowed to use the encrypted media extensions api (eme). when this policy is enabled, the promise returned by navigator.requestmediakeysystemaccess() will reject w...
... thrown. 130 feature-policy: encrypted-media directive, eme, feature policy, feature-policy, http, reference the http feature-policy header encrypted-media directive controls whether the current document is allowed to use the encrypted media extensions api (eme). when this policy is enabled, the promise returned by navigator.requestmediakeysystemaccess() will reject with a domexception. 131 feature-policy: fullscreen feature policy, feature-policy, http, fullscreen, header the http feature-policy header fullscreen directive controls whether the current document is allowed to use element.requestfullscreen(). when this policy is enabled, the returned promise rejects with a typeerror. 132 feature-policy: geolocation feature policy, feature-poli...
...mediadevices.getusermedia() will reject with a notallowederror. 138 feature-policy: midi directive, feature policy, feature-policy, http, midi, reference the http feature-policy header midi directive controls whether the current document is allowed to use the web midi api. when this policy is enabled, the promise returned by navigator.requestmidiaccess() will reject with a domexception. 139 feature-policy: oversized-images directive, feature-policy, http, reference the http feature-policy header oversized-images directive controls whether the current document is allowed to download and display large images. 140 feature-policy: payment directive, feature policy, feature-policy, http, payment request api, payments api, reference the http ...

Error - JavaScript
evalerror creates an instance representing an error that occurs regarding the global function eval(). internalerror creates an instance representing an error that occurs when an internal error in the javascript engine is thrown. e.g. ...
... evalerror creates an instance representing an error that occurs regarding the global function eval(). internalerror creates an instance representing an error that occurs when an internal error in the javascript engine is thrown. e.g. ...
... evalerror creates an instance representing an error that occurs regarding the global function eval(). internalerror creates an instance representing an error that occurs when an internal error in the javascript engine is thrown. e.g. "too much recursion". ...
...d: try { foo.bar() } catch (e) { if (e instanceof evalerror) { console.error(e.name + ': ' + e.message) } else if (e instanceof rangeerror) { console.error(e.name + ': ' + e.message) } // ... etc } custom error types you might want to define your own error types deriving from error to be able to throw new myerror() and use instanceof myerror to check the kind of error in the exception handler. this results in cleaner and more consistent error handling code. see "what's a good way to extend error in javascript?" on stackoverflow for an in-depth discussion. es6 custom error class versions of babel prior to 7 can handle customerror class methods, but only when they are declared with object.defineproperty(). otherwise, old versions of babel and other transpilers will not cor...

indexed-db - Archive of obsolete content
...
... ...
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passwords - Archive of obsolete content
namefield string the value of the name attribute for the user name input field in a form. passwordfield string the value of the name attribute for the password input field in a form. onerror function the callback function that is called if the function failed. the callback is passed an error containing a reason of a failure: this is an nsiexception object. store(options) this function is used to store a credential in the password manager. it takes an options object as an argument: this contains all the properties for the new credential. as different sorts of credentials contain different properties, the appropriate options differ depending on the sort of credential being stored. to store an add-on credential: require("sdk/pa...
...e name attribute for the password input in a form. omitted for add-on credentials and http authentication credentials. oncomplete function the callback function that is called once the function completes successfully. onerror function the callback function that is called if the function failed. the callback is passed an error argument: this is an nsiexception object. remove(options) removes a stored credential. you supply it all the properties of the credential to remove, along with optional oncomplete and onerror callbacks. because you must supply all the credential's properties, it may be convenient to call search first, and use its output as the input to remove. for example, to remove all of joe's stored credentials: require("sdk/pass...
...me attribute for the password input in a form. omitted for add-on credentials and http authentication credentials. oncomplete function the callback function that is called once the function has completed successfully. onerror function the callback function that is called if the function failed. the callback is passed an error argument: this is an nsiexception object. ...

console/traceback - Archive of obsolete content
ts a stack frame and has the following keys: filename the name of the file that the stack frame takes place in. lineno the line number is being executed at the stack frame. funcname the name of the function being executed at the stack frame, or null if the function is anonymous or the stack frame is being executed in a top-level script or module. see nsiexception for more information. globals functions fromexception(exception) attempts to extract the traceback from exception. parameters exception : exception exception where exception is an nsiexception. returns traceback : json representation of the traceback or null if not found. get() returns json : returns the json representation of the stack at the point that this function is called. form...
...re information. globals functions fromexception(exception) attempts to extract the traceback from exception. parameters exception : exception exception where exception is an nsiexception. returns traceback : json representation of the traceback or null if not found. get() returns json : returns the json representation of the stack at the point that this function is called. format(tborexception) given a json representation of the stack or an exception instance, returns a formatted plain text representation of it, similar to python's formatted stack tracebacks. if no argument is provided, the stack at the point this function is called is used. ...
...) returns json : returns the json representation of the stack at the point that this function is called. format(tborexception) given a json representation of the stack or an exception instance, returns a formatted plain text representation of it, similar to python's formatted stack tracebacks. ...

io/text-streams - Archive of obsolete content
ring text will be written to outputstream using the character encoding named by this value. if not specified, "utf-8" is assumed. see nsicharsetconvertermanager.idl for documentation on how to determine other valid values for this. textreader methods close() closes both the stream and its backing stream. read(numchars) reads and returns a string from the stream. if the stream is closed, an exception is thrown. parameters numchars : number the number of characters to read. if not given, the remainder of the stream is read. returns string : the string read. if the stream is at the end, the empty string is returned. properties closed true if the stream is closed. textwriter methods close() flushes the backing stream's buffer and closes both the stream and the backing stream. if the ...
...hars : number the number of characters to read. if not given, the remainder of the stream is read. returns string : the string read. if the stream is at the end, the empty string is returned. properties closed true if the stream is closed. textwriter methods close() flushes the backing stream's buffer and closes both the stream and the backing stream. if the stream is already closed, an exception is thrown. flush() flushes the backing stream's buffer. write(str) writes a string to the stream. if the stream is closed, an exception is thrown. parameters str : string the string to write. writeasync(str, callback) writes a string on a background thread. after the write completes, the backing stream's buffer is flushed, and both the stream and the backing stream are closed, also on th...
... parameters str : string the string to write. callback : callback callback, if given, must be a function. it's called as callback(error) when the write completes. error is an error object or undefined if there was no error. ...

XPCOM Objects - Archive of obsolete content
have to worry about queryinterface. but in this case we need to change the interface to nsiprefbranch2, which is the one that includes the method that adds a preference observer. then we change it back, because after that we only need to get and set preferences, and those methods are in nsiprefbranch. trying to access methods or attributes without having the right interface set will result in an exception being thrown. passing parameters passing parameters to xpcom methods is no different from other js objects, with some exceptions. in general, you can rely on javascript's ability to transform values to the correct type, but it's usually best to pass the right type in the first place. this section is a quick guide on how to read xpcom documentation, which basically amounts to understanding the s...
...cess constants through a reference of the component, or directly from the interface: // these are equivalent. max = ci.xsihellocounter.max_count; max = counterreference.max_count; the implementation file, xshellocounter.js, is much longer. we'll analyze it piece by piece. const cc = components.classes; const ci = components.interfaces; const cr = components.results; const ce = components.exception; you should be familiar with this already, although there are a couple of additions, components.results and components.exception. they'll be used further ahead. const class_id = components.id("{37ed5d2a-e223-4386-9854-b64fd38932bf}"); const class_name = "hello world counter"; const contract_id = "@xulschool.com/counter;1"; these constants are used at the bottom, in the component registra...
...tes must have the same names as their idl counterparts, and that the queryinterface method is implemented: queryinterface : function(aiid) { if (!aiid.equals(ci.xsihellocounter) && !aiid.equals(ci.nsisupports)) { throw cr.ns_error_no_interface; } return this; } the method is very simple, it validates that the caller is requesting a supported interface, otherwise it throws an exception. the rest of the code looks long and complicated, but it is pretty much the same for all components, so you shouldn't worry too much about it. all you have to do to use it in other components is copy it and change some names. the purpose of this code is to register the component so that you can get references to it just like all other firefox components. it is better read from bottom to top. ...

Index of archived content - Archive of obsolete content
vements in firefox 3 download manager preferences drag and drop drag and drop example drag and drop javascript wrapper drag and drop events editor embedding guide embedding faq embedding mozilla in a java application using javaxpcom error console exception logging in javascript existing content extension frequently asked questions external cvs snapshots in mozilla-central fast graphics performance with html firefox block and line layout cheat sheet content states and the style system disabling interruptible reflow document loadi...
... e4x tutorial accessing xml children descendants and filters introduction namespaces the global xml object iterator liveconnect liveconnect overview liveconnect reference jsexception jsobject msx emulator (jsmsx) old proxy api parallelarray properly using css and javascript in xhtml documents examples reference server-side javascript back to the server: server-...
... npn_invokedefault npn_memalloc npn_memflush npn_memfree npn_pluginthreadasynccall npn_posturl npn_posturlnotify npn_releaseobject npn_releasevariantvalue npn_reloadplugins npn_removeproperty npn_requestread npn_retainobject npn_setexception npn_setproperty npn_setvalue npn_setvalueforurl npn_status npn_utf8fromidentifier npn_useragent npn_version npn_write npobject npp nppvariable npp_destroy npp_destroystream npp_getvalue npp_handleevent npp_n...

MCD, Mission Control Desktop, AKA AutoConfig - Archive of obsolete content
compilation options mentioned above, i now get the following error message while stating thunderbird with autoconfig (autoconf.js having pref('general.config.filename','thunderbird.cfg'); ) and thunderbird.cfg calling getldap* functions to retrieve cn and mail address of the current user. netscape.cfg/autoconfig failed. please contact your system administrator. error: getldapattibutes failed: [exception... "component returned failure code: 0xc1f30001 (ns_error_not_initialized) [nsildapurl.spec]" nsresult: "0xc1f30001 (ns_error_not_initialized)" location: "js frame :: file:////usr/lib/thunderbird-3.0b2/defaults/autoconfig/prefcalls.js :: getldapattributes :: line 174" data: no] bug 295329 had been re-opened . autoconfig option and ldap support in thunderbird 1.5.x fortunately, autoconfig...
... // getldapattributes("ldap2.int-evry.fr","ou=people,dc=int-evry,dc=fr","uid=" + env_user,"uid,cn,mail,labeleduri"); // close the try, and call the catch() } catch(e) {displayerror("lockedpref", e);} if ldap call are uncommented in the preference file above, then i get a popup with: netscape.cfg/autoconfig failed. please contact your system administrator. error: getldapattibutes failed: [exception... "could not convert javascript argument arg 0 [nsisupports.queryinterface]" nsresult: "0x80570009 (ns_error_xpc_bad_convert_js)" location: "js frame :: prefcalls.js :: getldapattributes :: line 177" data: no] autoconfig (pref) and ldap support in packages add ldap support in firefox 1.5 a least from firefox 1.5, autoconfig is compiled by default (cf. browser, moz_extensions_default="pref.
...buildconfig (don't know the equivalent for thunderbird! ...

Embedding Mozilla in a Java Application using JavaXPCOM - Archive of obsolete content
it implements the iappfilelocprovider interface, and tells xpcom where to find certain files and directories. if your code cannot find the gre and keeps throwing fi...
...versionrange[] range = new greversionrange[1]; range[0] = new greversionrange("1.8.0", true, "1.9", false); // work with trunk nightly version 1.9a1 ^^ try { file grepath = mozilla.getgrepathwithproperties(range, null); locationprovider locprovider = new locationprovider(grepath); mozilla.initembedding(grepath, grepath, locprovider); } catch (filenotfoundexception e) { // this exception is thrown if gregrepathwithproperties cannot find a gre } catch (xpcomexception e) { // this exception is thrown if initembedding failed } locationprovider is a class provided by the java application. it implements the iappfilelocprovider interface, and tells xpcom where to find certain files and directories. if your code cannot find the gre and keeps throwing filenotfoundexceptions durin...
...ceptions during the getgrepathwithproperties(...) call, check whether you already registered the gre on your system: gre registration the initembedding method kicks off the embedding process, allowing the java application to work with xpcom and mozilla. once the java application is done using mozilla, it needs to terminate the embedding process: try { mozilla.termembedding(); } catch (xpcomexception e) { // this exception is thrown if termembedding failed } working with xpcom objects now that mozilla is embedded, the java application can work with xpcom objects. the mozilla class provides several methods to facilitate this, such as getservicemanager, getcomponentmanager, and newlocalfile. in addition to retrieving and calling methods on xpcom objects, javaxpcom allows the java applica...

LiveConnect Reference - Archive of obsolete content
jsobject the public class jsobject extends object. ...
... jsobject the public class jsobject extends object. ...
... jsobject the public class jsobject extends object. ...

Componentizing our React app - Learn web development
browser. our todo component is complete, at least for now; now we can use it. in app.js, add the following line near the top of the file to import todo: import todo from "./components/todo"; with this component imported, you can replace all of the <li> elements in app.js with <todo /> component calls. your <ul> should read like this: <ul role="list" classname="todo-list stack-large stack-exception" aria-labelledby="list-heading" > <todo /> <todo /> <todo /> </ul> when you look back at your browser, you'll notice something unfortunate: your list now repeats the first task three times! we don't only want to eat; we have other things to — well — to do. next we'll look at how we can make different component calls render unique content. make a unique <todo /> components are po...
...ng else: array.prototype.map(). above the return statement of app(), make a new const called tasklist and use map() to transform it. let's start by turning our tasks array into something simple: the name of each task: const tasklist = props.tasks.map(task => task.name); let’s try replacing all the children of the <ul> with tasklist: <ul role="list" classname="todo-list stack-large stack-exception" aria-labelledby="list-heading" > {tasklist} </ul> this gets us some of the way towards showing all the components again, but we’ve got more work to do: the browser currently renders each task's name as unstructured text. we’re missing our html structure — the <li> and its checkboxes and buttons! to fix this, we need to return a <todo /> component from our map() function — remembe...
...filterbutton from "./components/filterbutton"; import todo from "./components/todo"; function app(props) { const tasklist = props.tasks.map(task => ( <todo id={task.id} name={task.name} completed={task.completed} key={task.id} /> ) ); return ( <div classname="todoapp stack-large"> <form /> <div classname="filters btn-group stack-exception"> <filterbutton /> <filterbutton /> <filterbutton /> </div> <h2 id="list-heading">3 tasks remaining</h2> <ul role="list" classname="todo-list stack-large stack-exception" aria-labelledby="list-heading" > {tasklist} </ul> </div> ); } export default app; with this in place, we’re almost ready to tackle s...

Examples
eturn any value. when newpromise is fulfilled, nothing happens, because no fulfillment callback is specified and the return value of the last then method is ignored. if the file existence check fails, for example because access is denied, promise is rejected with an os.file.error instance. this state will propagate to newpomise, and components.utils.reporterror will report all the details of the exception to the console. using a promise returned by a function (compact) the same code as the previous example is usually written with a more compact syntax: components.utils.import("resource://gre/modules/osfile.jsm") let path = os.path.join(os.constants.path.tmpdir, "file.txt"); os.file.exists(path).then(exists => { console.log(exists ? "you have file.txt in your temporary directory." ...
...ypromise.then( function(asuccessreason) { alert('mypromise was succesful and reason was = "' + asuccessreason + '"'); }, function(arejectreason) { alert('mypromise failed for reason = "' + uneval(arejectreason) + '"'); } ); function myuserdefinedpromise() { return 'i didnt do a promise.resolve so this will not understand that mypromise is a promise'; } // creates this error: /* exception: mypromise.then is not a function @scratchpad/5:8:1 wca_evalwithdebugger@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/devtools/server/actors/webconsole.js:1069:7 wca_onevaluatejs@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/devtools/server/actors/webconsole.js:734:9 dsc_onpacket@resource://gre/modules/commonjs/toolkit/loader.js -> reso...
...eaftertimeout(avalue, atimeout) { let deferred = promise.defer(); try { // an asynchronous operation will trigger the resolution of the promise. // in this example, we don't have a callback that triggers a rejection. settimeout(function () { deferred.resolve('rawr my success value'); }, atimeout); } catch (ex) { // generally, functions returning promises propagate exceptions through // the returned promise, though they may also choose to fail early. deferred.reject(ex); } // we don't return the deferred to the caller, but only the contained // promise, so that the caller cannot accidentally change its state. return deferred.promise; } // this code uses the promise returned be the function above. let promise = promisevalueaftertimeout("value", 1000)...

Promise.jsm
filled, when and if the final value becomes available. a fulfillment value becomes permanently associated with the promise. this may be any value, including undefined. rejected, if an error prevented the final value from being determined. a rejection reason becomes permanently associated with the promise. this may be any value, including undefined, though it is generally an error object, like in exception handling. a reference to an existing promise may be received by different means, for example as the return value of a call into an asynchronous api. in this case, the state of the promise can be observed but not directly controlled. to observe the state of a promise, its then method must be used. this method registers callback functions that are called as soon as the promise is either fulfille...
...e observed but not directly controlled. to observe the state of a promise, its then method must be used. this method registers callback functions that are called as soon as the promise is either fulfilled or rejected. the method returns a new promise that, in turn, is fulfilled or rejected depending on the state of the original promise and on the behavior of the callbacks. for example, unhandled exceptions in the callbacks cause the new promise to be rejected, even if the original promise is fulfilled. see the documentation of the then method for details. promises may also be created using the new promise() constructor. method overview deferred defer(); obsolete since gecko 30 promise resolve([optional] avalue); promise reject([optional] areason); methods defe...
.... it will eventually assume the same state as the provided promise. return value a promise that can be pending, fulfilled, or rejected. reject() creates a new promise rejected with the specified reason. promise reject( areason ); parameters areason optional the rejection reason for the returned promise. although the reason can be undefined, it is generally an error object, like in exception handling. note: this argument should not be a promise. specifying a rejected promise would make the rejection reason equal to the rejected promise itself, and not its rejection reason. return value a rejected promise. examples see the examples page. ...

NSS API Guidelines
ct secmyopaquedatastr { unsigned long myprivatedata1; unsigned long myprivatedata2; char *myname; }; the second task is to determine if individual data fields, within the data structure, are part of the api. one example may be the peercert field, in an ssl data structure. accessor functions, for these data elements, should be added to the api. there can be legitimate exceptions to this 'make everything opaque' rule. for example, in container structures, such as secitem, or maybe linked list data structures. these data structures need to be examined on a case by case basis, to determine if they are truly stable and will not change in future release it is necessary for the callers of the api to know the size of these structures, as they may allocate new ones and pass...
...ly called by a destroy function. finally, error logging should be added an documented when debug is turned on. interfaces for these are in nspr. thread safety code developed using the nss apis needs to make use of thread safety features. first to examine is object creation and deletion. object creation is usually not a problem. no other threads have access to allocated memory just created. exceptions to this include objects which are created on the fly, or as global objects. deletion, on the other hand, may be trickier. threads may be referencing the object at the same time a another thread tries to delete it. the semantics depend on the way the application uses the object, also how and when the application wants to destroy it. for some data structures, this problem can be removed by protec...
...bal data, particularly if they may be called multiple times, to provide different semantics for different operations. for example, the following should be avoided : sec_setkey(keyforoperation); sec_encrypt(data,length); instead, a context handle should be created, and the sec_setkey() function, above, made on that handle. fortunately most of the existing api has the correct semantics. the exception to this global effects rule may be functions which set global state for an application at initialization time. methods/functions design init, shutdown functions if a layer has some global initialization tasks, which need to be completed before the layer can be used, that layer should supply an initialization function of the form layer_init(). if an initialization function is supplied, a...

Rhino shell
output property. err - the process error output instead of java.lang.system.err. if it is not instance of java.io.outputstream, the process error output is read, converted to a string, appended to the err property value converted to string and put as the new value of the err property. seal(object) seal the specified object so any attempt to add, delete or modify its properties would throw an exception. serialize(object, filename) serialize the given object to the specified file. spawn(functionorscript) run the given function or script in a different thread. sync(function) creates a synchronized function (in the sense of a java synchronized method) from an existing function. the new function synchronizes on the this object of its invocation. quit() quit shell. the shell will also quit i...
...: 'sort output:\n'} js> runcommand("sort", opt) 0 js> print(opt.output) sort output: a b c js> var opt={input: "c\na\nb", output: 'sort output:\n', err: ''} js> runcommand("sort", "--bad-arg", opt) 2 js> print(opt.err) /bin/sort: unrecognized option `--bad-arg' try `/bin/sort --help' for more information. ...
...s> runcommand("sort", opt) 0 js> print(opt.output) sort output: a b c js> var opt={input: "c\na\nb", output: 'sort output:\n', err: ''} js> runcommand("sort", "--bad-arg", opt) 2 js> print(opt.err) /bin/sort: unrecognized option `--bad-arg' try `/bin/sort --help' for more information. ...

JSErrorReport
code line buffer. this is the buffer that contains the original data. uctokenptr const char16_t * pointer to the error token in *uclinebuf. flags unsigned the logical or of zero or more of the following flags: jsreport_warning this "error" is really only a warning. it will not cause the current operation to fail. jsreport_exception an exception is being raised. a jserrorreporter might choose to ignore a jserrorreport that has this flag set, since the exception may be caught and handled by javascript code. jsreport_strict this error is only being reported because the engine is in strict mode. jsreport_strict_mode_error this condition is an error in strict mode code,...
...uf to point at the buffer before your application executes a script. for unicode scripts, define a second buffer that holds the unicode version of the text the generated the error. for application that do not use unicode, set uclinebuf and uctokenptr to null. macros name description jsreport_is_warning(flags) returns true if flags has jsreport_warning. jsreport_is_exception(flags) returns true if flags has jsreport_exception. jsreport_is_strict(flags) returns true if flags has jsreport_strict. jsreport_is_strict_mode_error(flags) returns true if flags has jsreport_strict_mode_error. see also mxr id search for jserrorreport js_reporterror js_reportwarning js_reportoutofmemory js_seterrorreporter js_reporterrornumber js_reporte...
... returns true if flags has jsreport_strict. jsreport_is_strict_mode_error(flags) returns true if flags has jsreport_strict_mode_error. see also mxr id search for jserrorreport js_reporterror js_reportwarning js_reportoutofmemory js_seterrorreporter js_reporterrornumber js_reporterrornumberuc js_reporterrorflagsandnumber js_reporterrorflagsandnumberuc js_reportpendingexception ...

JSAPI reference
ction added in spidermonkey 17 js_decompilefunction js_decompilefunctionbody js_compilefunction obsolete since jsapi 36 js_compilefunctionforprincipals obsolete since jsapi 28 js_compileucfunction obsolete since jsapi 36 js_compileucfunctionforprincipals obsolete since jsapi 28 error handling struct jserrorformatstring added in spidermonkey 17 class jserrorreport class js::autosaveexceptionstate added in spidermonkey 31 enum jsexntype added in spidermonkey 17 js_reporterror js_reportwarning js_reporterrornumber js_reporterrornumberuc js_reporterrorflagsandnumber js_reporterrorflagsandnumberuc js_reporterrornumberucarray added in spidermonkey 24 js_reportoutofmemory js_reportallocationoverflow added in spidermonkey 1.8 js_geterrorreporter js_seterrorreporterobsolete since...
...nkey 31 enum jsexntype added in spidermonkey 17 js_reporterror js_reportwarning js_reporterrornumber js_reporterrornumberuc js_reporterrorflagsandnumber js_reporterrorflagsandnumberuc js_reporterrornumberucarray added in spidermonkey 24 js_reportoutofmemory js_reportallocationoverflow added in spidermonkey 1.8 js_geterrorreporter js_seterrorreporterobsolete since jsapi 52 js_errorfromexception js_geterrorprototype jsreport_is_exception jsreport_is_strict jsreport_is_warning jsreport_is_strict_mode_error the following functions allow c/c++ functions to throw and catch javascript exceptions: js::createerror added in spidermonkey 38 js_isexceptionpending js_getpendingexception js_setpendingexception js_clearpendingexception js_throwstopiteration added in spidermonkey 1.8 j...
...s_strict jsreport_is_warning jsreport_is_strict_mode_error the following functions allow c/c++ functions to throw and catch javascript exceptions: js::createerror added in spidermonkey 38 js_isexceptionpending js_getpendingexception js_setpendingexception js_clearpendingexception js_throwstopiteration added in spidermonkey 1.8 js_isstopiteration added in spidermonkey 31 typedef jsexceptionstate js_saveexceptionstate js_restoreexceptionstate js_dropexceptionstate these functions translate errors into exceptions and vice versa: js_reportpendingexception js_errorfromexception js_throwreportederror obsolete since jsapi 29 values and types typedef jsval js::value js::value constructors: js::nullvalue added in spidermonkey 24 js::undefinedvalue added in spiderm...

Secure Development Guidelines
ed write to un-initialized file descriptor checking return values check all return values—no matter how unlikely the api failure for example: close() can fail and leak file descriptor setuid() can fail and privileges don’t get dropped snprintf() can fail and result in return value -1 tmp = realloc(tmp, size) — realloc could fail and leak tmp writing secure code: exception handling double freeing pointers double frees can occur in exception handling they free data in try block and then free it again in the catch block this is a common issue double freeing pointers char *ptr1 = null, *ptr2 = null; try { ptr1 = new char[1024]; do_something(); delete ptr1; do_something_else(); ptr2 = new char[-1] // oom } catch (...) { delete p...
...ees can occur in exception handling they free data in try block and then free it again in the catch block this is a common issue double freeing pointers char *ptr1 = null, *ptr2 = null; try { ptr1 = new char[1024]; do_something(); delete ptr1; do_something_else(); ptr2 = new char[-1] // oom } catch (...) { delete ptr1; delete ptr2; } new will throw an exception — ptr1 is already freed in the try block then freed again in the catch block freeing un-initialized data free data in the catch block assumption is that it’s initialized in the try block if the try block throws before the variable is initialized, the catch block will operate on un-intialized data freeing un-initialized data example: int main(){ char *ptr; try { ...
... delete p; } catch (...) { ... } } memory leaks: prevention any acquired resource in a try block should be freed in a catch block (if the try block throws before the resource is freed) might be helpful to initialize variables null for pointers -1 for file descriptors ...

An Overview of XPCOM
n simple class inheritance, for example, you'd like to be able ask the shape if it's a circle and to be able to use it like a circle if it is. in xpcom, this is what the queryinterface feature of the nsisupports interface is for: it allows clients to find and access different interfaces based on their needs. in c++, you can use a fairly advanced feature known as a dynamic_cast<>, which throws an exception if the shape object is not able to be cast to a circle. but enabling exceptions and rtti may not be an option because of performance overhead and compatibility on many platforms, so xpcom does things differently. exceptions in xpcom c++ exceptions are not supported directly by xpcom. instead all exceptions must be handled within a given component, before crossing interface boundaries. in xpcom...
... instead of leveraging c++ rtti, xpcom uses the special queryinterface method that casts the object to the right interface if that interface is supported. every interface is assigned an identifier that gets generated from a tool commonly named "uuidgen". this universally unique identifier (uuid) is a unique, 128-bit number. ...
... ns_imethod method declaration return type. xpcom method declarations should use this as their return type. ns_imethodimp method implementation return type. xpcom method implementations should use this as their return type. ns_imethodimp_(type) special case implementation return type. some methods such as addref and release do not return the default return type. this exception is regrettable, but required for com compliance. ns_import forces the method to be resolved internally by the shared library. ns_export forces the method to be exported by the shared library. reference counting these macros manage reference counting. ns_addref calls addref on an nsisupports object. ns_if_addref same as above but checks for ...

mozIStorageService
r_file_corrupted. note: the connection object returned by this function is not threadsafe. you must use it only from the thread you created it from. mozistorageconnection opendatabase( in nsifile adatabasefile ); parameters adatabasefile an nsifile indicating the database file to open. return value a mozistorageconnection representing the connection to the opened database file. exceptions thrown ns_error_failure an error occurred attempting to open the database. ns_error_file_corrupted the database file is corrupted, or contains virtual tables and is not compatible with this method. ns_error_out_of_memory allocating a new storage object failed. openspecialdatabase() opens a connection to a named special database storage that identifies ...
... you should only access the profile database from the main thread since other callers may also be using it. mozistorageconnection openspecialdatabase( in string astoragekey ); parameters astoragekey a string key identifying the type of storage requested. valid values are "profile" and "memory". return value a new mozistorageconnection providing access to the requested database. exceptions thrown ns_error_invalid_arg if astoragekey is invalid. openunshareddatabase() opens a database connection to the specified file without using a shared cache. if this method throws ns_error_file_corrupted, it's recommended that you call mozistorageservice.backupdatabasefile() to back up the database so that user data is not lost (although we have no way of recovering this data yet...
...atabase. note: the connection object returned by this function is not threadsafe. you must use it only from the thread you created it from. mozistorageconnection openunshareddatabase( in nsifile adatabasefile ); parameters adatabasefile an nsifile indicating the database file to open. return value a mozistorageconnection representing the connection to the opened database file. exceptions thrown ns_error_failure an error occurred attempting to open the database. ns_error_file_corrupted the database file is corrupted, or contains virtual tables and is not compatible with this method. ns_error_out_of_memory allocating a new storage object failed. see also storage mozistorageconnection ...

nsIArray
element); void queryelementat(in unsigned long index, in nsiidref uuid, [iid_is(uuid), retval] out nsqiresult result); attributes attribute type description length unsigned long the number of elements in the array. read only. methods enumerate() enumerate the array. nsisimpleenumerator enumerate(); parameters none. return value a new enumerator positioned at the start of the array. exceptions thrown ns_error_failure if the array is empty (to make it easy to detect errors). ns_error_out_of_memory if there is not enough memory to complete the operation. indexof() get the position of a specific element. note that since null is a valid input, exceptions are used to indicate that an element is not found. unsigned long indexof( in unsigned long startindex, in nsisupports element ); ...
...input, exceptions are used to indicate that an element is not found. unsigned long indexof( in unsigned long startindex, in nsisupports element ); parameters startindex the initial element to search in the array. to start at the beginning, use 0 as the startindex. element the element you are looking for. return value a number >= startindex which is the position of the element in the array. exceptions thrown ns_error_failure if the element was not in the array. queryelementat() retrieve a specific element of the array, and queryinterface it to the specified interface. null is a valid result for this method, but exceptions are thrown in other circumstances. void queryelementat( in unsigned long index, in nsiidref uuid, [iid_is(uuid), retval] out nsqiresult result ); parameters index ...
... queryinterface it to the specified interface. null is a valid result for this method, but exceptions are thrown in other circumstances. void queryelementat( in unsigned long index, in nsiidref uuid, [iid_is(uuid), retval] out nsqiresult result ); parameters index position of element. uuid the iid of the requested interface. result the object, queryinterface'd to the requested interface. exceptions thrown ns_error_illegal_value when index > length-1. see also nsimutablearray ...

nsIChannelEventSink
.e. it was not initiated by the remote server, but is specific to the channel implementation. the new uri may be identical to the old one. methods asynconchannelredirect() called when a redirect occurs. this may happen due to an http 3xx status code. this method notifies the sink that a redirect is about to happen, but also to gives the sink the right to veto the redirect by throwing an exception or passing a failure code in the callback. note: vetoing the redirect simply means that newchannel will not be opened. it is important to understand that oldchannel will continue loading as if it received a response of http 200, which includes notifying observers and possibly display or process content attached to the http response. if the sink wants to prevent this loading it must explicitly dea...
... e.g. by calling oldchannel->cancel() there is a certain freedom in implementing this method: if the return-value indicates success, a callback on callback is required. this callback can be done from within asynconchannelredirect() (effectively making the call synchronous) or at some point later (making the call asynchronous). if the return value indicates that an error occurred, in which case an exception is thrown, the redirect is vetoed and no callback must be done. void asynconchannelredirect( in nsichannel oldchannel, in nsichannel newchannel, in unsigned long flags, in nsiasyncverifyredirectcallback callback ); parameters oldchannel the channel that's being redirected. newchannel the new channel. this channel is not opened yet. flags flags indicating the type...
...rectcallback callback ); parameters oldchannel the channel that's being redirected. newchannel the new channel. this channel is not opened yet. flags flags indicating the type of redirect. a bitmask consisting of flags from above. one of redirect_temporary and redirect_permanent will always be set. callback object to inform about the async result of this method. exceptions thrown this method can throw any exception; if an exception occurs, the load will be canceled, and no network requests will occur for the new channel. the redirect will be canceled. onchannelredirect() obsolete since gecko 2.0 (firefox 4 / thunderbird 3.3 / seamonkey 2.1) called when a redirect occurs. this may happen due to an http 3xx status code. void onchannelredire...

nsIDOMMozNetworkStatsManager
ptions. networkstatsgetoptions is a dictionary object providing filtering options. return value an nsidomdomrequest object. if successful, the request result is an nsidommoznetworkstats object describing the network statistics. if network stats are not available for some dates, then rxbytes and txbytes are undefined for those dates. if the filtering start date is greater than the end date, an exception is thrown. exceptions thrown ns_error_invalid_arg the filtering start date is greater than the end date. ns_error_not_implmented both appmanifesturl and servicetype are specified at the same time in the networkstatsgetoptions dictionary. invalidnetwork the network must be in the return of getavailablenetworks. addalarm() install an alarm on a network. when total data usage reaches thr...
...kind of origin is available, the moznetworkstatsmanager.getavailablenetworks method returns an array of interfaces. threshold the total data usage threshold in bytes. options optional filtering options. networkstatsalarmoptions is a dictionary object providing filtering options. return value an nsidomdomrequest object. if successful, the result field of the domrequest keeps the alarm id. exceptions thrown invalidnetwork the network must be in the return of getavailablenetworks. getallalarms() obtain all alarms for those networks returned by getavailablenetworks. if a network is provided, only retrieves the alarms for that network. nsidomdomrequest getallalarms([optional] in nsisupports network); parameters network optional the origin of the data. it can specify wifi, mobile, o...
...etwork optional the origin of the data. it can specify wifi, mobile, or null. if null, data measurement from both origins are merged. to know in advance which kind of origin is available, the moznetworkstatsmanager.getavailablenetworks method returns an array of interfaces. return value an alarm object with the same fields as that in the system message; alarmid, network, threshold, and data. exceptions thrown invalidnetwork the network must be in the return of getavailablenetworks. removealarms() remove all network alarms. if an alarmid is provided, then only that alarm is removed. nsidomdomrequest removealarms([optional] in long alarmid); parameters alarmid id of an alarm, like the one returned by addalarm. return value an nsidomdomrequest object. clearstats() remove all st...

nsIFocusManager
native code only! attributes attribute type description activewindow nsidomwindow the most active (frontmost) window, or null if no window that is part of the application is active. setting the activewindow raises it, and focuses the current child window's current element, if any. setting this to null or to a non-top-level window throws an ns_error_invalid_arg exception. focusedelement nsidomelement the element that is currently focused. this will always be an element within the document loaded in focusedwindow or null if no element in that document is focused. read only. focusedwindow nsidomwindow the child window within the activewindow that is focused. this will always be activewindow, a child window of activewindow or null if no...
... move focus to a link at the position of the caret. this is a special value used to focus links as the caret moves over them in caret browsing mode. methods clearfocus() clears the focused element within awindow. if the current focusedwindow is a descendant of awindow, sets the current focusedwindow to awindow. void clearfocus( in nsidomwindow awindow ); parameters awindow exceptions thrown ns_error_invalid_arg if awindow is null. native code only!contentremoved obsolete since gecko 2.0 (firefox 4 / thunderbird 3.3 / seamonkey 2.1)this feature is obsolete. although it may still work in some browsers, its use is discouraged since it could be removed at any time. try to avoid using it. called when content has been removed. void contentremoved( in nsidocument adoc...
...n value may be the element within a child descendant window that is focused. if false, then the return value will be the frame element if the focus is in a child frame. afocusedwindow will be set to the currently focused descendant window of awindow, or to awindow if adeep is false. this will be set even if no element is focused. return value the currently focused element within awindow. exceptions thrown ns_error_invalid_arg if awindow is null. getlastfocusmethod() pruint32 getlastfocusmethod( in nsidomwindow window ); parameters window if null, then the current focusedwindow will be used by default. this has the result of retrieving the method that was used to focus the currently focused element. return value the method that was used to focus the element in window.

nsIJumpListBuilder
optional); boolean commitlistbuild(); boolean deleteactivelist(); boolean initlistbuild(in nsimutablearray removeditems); attributes attribute type description available short indicates whether jump list taskbar features are supported by the current host. read only. islistcommitted boolean jumplist management. indicates if a commit has already occurred in this session. read only. exceptions thrown ns_error_not_available on all calls if taskbar functionality is not supported by the operating system. maxlistitems short the maximum number of jump list items the current desktop can support. read only. constants constant value description jumplist_category_tasks 0 tasks are common actions performed by users within the application. a task can be represented by an applicatio...
...adds a list and if required, a set of items for the list. boolean addlisttobuild( in short acattype, in nsiarray items, optional in astring catname optional ); parameters acattype the type of list to add. items optional an array of nsijumplistitem items to add to the list. catname optional for custom lists, the title of the list. return value true if the operation completed successfully. exceptions thrown ns_error_unexpected on internal errors. ns_error_illegal_value if an item is added that was removed since the last commit. ns_error_invalid_arg if incorrect parameters are passed for a particular category or item type. commitlistbuild() commits the current jump list build to the taskbar. boolean commitlistbuild(); parameters none. return value true if the operation completed successful...
...mp list build to the taskbar. boolean commitlistbuild(); parameters none. return value true if the operation completed successfully. deleteactivelist() deletes any currently applied taskbar jump list for this application. common uses would be the enabling of a privacy mode and uninstallation. boolean deleteactivelist(); parameters none. return value true if the operation completed successfully. exceptions thrown ns_error_unexpected on internal errors. initlistbuild() initializes a jump list build and returns a list of items the user removed since the last time a jump list was committed. removed items can become state after initlistbuild is called, lists should be built in single-shot fashion. boolean initlistbuild( in nsimutablearray removeditems ); parameters removeditems a list of items t...

nsIMimeHeaders
headerssize); attributes attribute type description allheaders string read only. ...
... attribute type description allheaders string read only. ...
... missing description getallofthem missing description return value missing description exceptions thrown missing exception missing description initialize() void initialize( [const] in string allheaders, in long allheaderssize ); parameters allheaders insert the complete message content allheaderssize length of the passed in content exceptions thrown missing exception missing description remarks see also ...

nsIMsgRuleAction
defined in comm-central/ mailnews/ base/ search/ public/ nsimsgfilter.idl [scriptable, uuid(190a2a18-d245-473a-a402-9f0814598c7f)] interface nsimsgruleaction : nsisupports { attribute nsmsgruleactiontype type; // target priority.. throws an exception if the action is not priority attribute nsmsgpriorityvalue priority; // target folder.. throws an exception if the action is not move to folder attribute acstring targetfolderuri; // target label. ...
...[scriptable, uuid(190a2a18-d245-473a-a402-9f0814598c7f)] interface nsimsgruleaction : nsisupports { attribute nsmsgruleactiontype type; // target priority.. throws an exception if the action is not priority attribute nsmsgpriorityvalue priority; // target folder.. throws an exception if the action is not move to folder attribute acstring targetfolderuri; // target label. ...
...{ attribute nsmsgruleactiontype type; // target priority.. throws an exception if the action is not priority attribute nsmsgpriorityvalue priority; // target folder.. throws an exception if the action is not move to folder attribute acstring targetfolderuri; // target label. ...

nsIMutableArray
eelementat(in unsigned long index); void replaceelementat(in nsisupports element, in unsigned long index, in boolean weak); methods appendelement() append an element at the end of the array. void appendelement( in nsisupports element, in boolean weak ); parameters element the element to append. weak whether or not to store the element using a weak reference. exceptions thrown ns_error_failure when a weak reference is requested, but the element does not support nsiweakreference. clear() clear the entire array, releasing all stored objects. void clear(); parameters none. insertelementat() insert an element at the given position, moving the element currently located in that position, and all elements in higher position, up by one. void insertelementat(...
...: if the position is lower than the current length of the array, the elements at that position and onwards are bumped one position up. if the position is equal to the current length of the array, the new element is appended. an index lower than 0 or higher than the current length of the array is invalid and will be ignored. weak whether or not to store the element using a weak reference. exceptions thrown ns_error_failure when a weak reference is requested, but the element does not support nsiweakreference. removeelementat() remove an element at a specific position, moving all elements stored at a higher position down one. to remove a specific element, use nsiarray.indexof() to find the index first, then call removeelementat. void removeelementat( in unsigned long index ); par...
...ting element will be replaced. if the position is equal to the current length of the array, the new element is appended. if the position is higher than the current length of the array, empty elements are appended followed by the new element at the specified position. an index lower than 0 is invalid and will be ignored. weak whether or not to store the new element using a weak reference. exceptions thrown ns_error_failure when a weak reference is requested, but the element does not support nsiweakreference. see also nsiarray ...

nsIScriptableInputStream
currently available in the stream. note: this method should not be used to determine the total size of a stream, even if the stream corresponds to a local file. moreover, since a stream may make available more than 2^32 bytes of data, this method is incapable of expressing the entire size of the underlying data source. unsigned long available(); parameters none. return value the number of bytes. exceptions thrown ns_base_stream_closed if called after the stream has been closed. close() closes the stream. note: the close method may be called more than once, but subsequent calls are ignored. void close(); parameters none. init() wrap the given nsiinputstream with this nsiscriptableinputstream. note: the init method may be called more than once, allowing a nsiscriptableinputstream instance...
...articular, some bindings may convert the byte values into unicode code points, by assuming the byte values are encoded as iso-latin-1. this is the case for the javascript bindings. string read( in unsigned long acount ); parameters acount the maximum number of bytes to read from the stream. return value the data read as a string, which will be an empty string if the stream is at eof. exceptions thrown ns_error_not_initialized if init() was not called. ns_base_stream_closed if called after the stream has been closed. ns_base_stream_would_block indicates that reading from the input stream would block the calling thread for an indeterminate amount of time. this exception may only be thrown if nsiinputstream.isnonblocking() returns true. readbytes() read data from...
... ns_base_stream_would_block if reading from the input stream would block the calling thread (non-blocking mode only). remarks this interface provides javascript with a way to read ascii text from a nsiinputstream. ...

nsISessionStore
cription canrestorelastsession boolean is it possible to restore the previous session. will always be false when in private browsing mode. methods deletetabvalue() deletes a value from a specified tab. void deletetabvalue( in nsidomnode atab, in astring akey ); parameters atab the tab for which to delete the value. akey the key whose value is to be deleted. exceptions thrown this method throws a ns_error_illegal_value exception if the key doesn't exist. deletewindowvalue() deletes a value from a specified window. void deletewindowvalue( in nsidomwindow awindow, in astring akey ); parameters awindow the window in which to delete the value. akey the key whose value is to be deleted. duplicatetab() duplicates a specified tab as thoroughly as p...
...window awindow, in unsigned long aindex ); parameters awindow is the browser window associated with the closed tab. aindex is the index of the closed tab to be removed (fifo ordered). return value forgetclosedwindow() nsidomnode forgetclosedwindow( in unsigned long aindex ); parameters aindex is the index of the closed window to be removed (fifo ordered). return value exceptions thrown ns_error_invalid_arg when aindex does not map to a closed window. getbrowserstate() returns the current state of all of windows and all of their tabs. astring getbrowserstate(); parameters none. return value a json string representing the current state of all windows in the web browser. getclosedtabcount() returns the number of restorable tabs for a given window. unsigned ...
...fied window in the web browser. astring getwindowstate( in nsidomwindow awindow ); parameters awindow the browser window whose state is to be returned. see #note on windows. return value a json string representing a session state that contains only the window specified by awindow. if the preference browser.sessionstate.enabled is false when this method is called, then you will get an exception about "awindows[i] has no properties". getwindowvalue() returns the string value associated with a given key for a window. astring getwindowvalue( in nsidomwindow awindow, in astring akey ); parameters awindow the window from which the value is to be retrieved. akey the key whose corresponding value is to be retrieved. return value the string value that was previously assigned t...

nsIThread
l, events for the current thread may continue to be processed. warning: this method may not be called from the thread itself. instead, you must only call it from another thread (usually the thread that created it, or the main application thread). when this function returns, the thread will be shut down and will no longer be available to receive events. void shutdown() parameters none. exceptions thrown ns_error_unexpected shutdown() was erroneously called from within the thread itself, the thread was not created with the thread manager's nsithreadmanager.newthread() method, or the thread is already in the process of being shut down. haspendingevents() determines whether or not the thread has events that are ready to be processed. note: this method must be called from within the ...
...thod must be called from within the thread itself, and not from another thread. boolean haspendingevents() parameters none. return value true if there are pending events at the time the function was called. since other threads may add events to the current thread, it's possible that by the time this method returns, the event queue may no longer be empty, even if a false result is reported. exceptions thrown ns_error_unexpected the method was called when this thread wasn't the current thread. processnextevent() processes the next pending event. if there aren't any pending events, this method may wait -- depending on the value of the maywait parameter -- until an event is dispatched to the thread. this method is re-entrant but may only be called if this thread is the current thread. ...
... to find and fix. consider use asynchronous callbacks instead. boolean processnextevent( in boolean maywait ); parameters maywait if true, this method blocks until an event is available to process if the event queue is empty. if false, this method returns immediately if the queue is empty. return value returns true if an event was processed, or false if there were no pending events. exceptions thrown ns_error_unexpected this method was called when this thread wasn't the current thread. see also the thread manager nsithreadmanager nsithreadpool nsithreadinternal nsithreadobserver nsithreadeventfilter ...

nsIToolkitProfileService
n where the profile directory is located. nsitoolkitprofile createprofile( in nsilocalfile arootdir, in autf8string aname ); parameters arootdir the profile directory. may be null, in which case a suitable default will be chosen based on the profile name. aname the name to give the new profile. return value an nsitoolkitprofile object representing the newly-created profile. exceptions thrown ns_error_unexpected an unexpected error condition occurred. ns_error_file_not_directory one of the specified directory files is not actually a directory. ns_error_out_of_memory unable to allocate the new profile object. flush() flushes the profile list to disk. the profile list file is constructed in memory, then written out as one large chunk, in order to reduce...
..._directory one of the specified directory files is not actually a directory. ns_error_out_of_memory unable to allocate the new profile object. flush() flushes the profile list to disk. the profile list file is constructed in memory, then written out as one large chunk, in order to reduce the risk of the profile list file being corrupted by disk errors. void flush(); parameters none. exceptions thrown ns_error_out_of_memory an error occurred trying to allocate the memory buffer used to construct the profile list. ns_error_unexpected an error occurred writing the profile list file to disk. getprofilebyname() gets a profile, given the profile's name. nsitoolkitprofile getprofilebyname( in autf8string aname ); parameters aname the profile name to find. retur...
...llocate the memory buffer used to construct the profile list. ns_error_unexpected an error occurred writing the profile list file to disk. getprofilebyname() gets a profile, given the profile's name. nsitoolkitprofile getprofilebyname( in autf8string aname ); parameters aname the profile name to find. return value an nsitoolkitprofile object describing the specified profile. exceptions thrown ns_error_failure no matching profile was found. lockprofilepath() locks an arbitrary path as a profile. if the path does not exist, it is created and the defaults copied from the application directory. nsiprofilelock lockprofilepath( in nsilocalfile adirectory, in nsilocalfile atempdirectory ); parameters adirectory the directory to lock as a profile directory. ...

nsIWebBrowserPersist
a nsilocalfile object or an nsiuri object with a file scheme. aoutputcontenttype the desired mime type format to save the document and all sub-documents into or nsnull to use the default behavior. aencodingflags flags to pass to the encoder. awrapcolumn for text documents, indicates the desired width to wrap text at. parameter is ignored if wrapping is not specified by the encoding flags. exceptions thrown ns_error_invalid_arg one or more arguments was invalid. saveuri() as of firefox 26, this method should no longer be used from add-on code. please use downloads.createdownload() instead. as of firefox 36, a new parameter areferrerpolicy was added as the fourth argument, changing the number of parameters from 7 to 8 and shifting the order of the parameters in a backwards incompatib...
...anent cache, etc.) null must only be passed in the event that no such relevant context exists (ie. the uri being saved is unrelated to any current browsing session). important: if you think that you should be passing null here, you are almost certainly wrong. null should be passed only when no plausible privacy context exists for the uri to be saved, which is an exceedingly rare corner case. ...
...assed only when no plausible privacy context exists for the uri to be saved, which is an exceedingly rare corner case. exceptions thrown ns_error_invalid_arg one or more arguments was invalid. saveprivacyawareuri() save the specified uri to file, explicitly dictating whether the operation should be considered private for the purposes of network requests, caching, etc. all arguments and exceptions are identical to saveuri, with the exception of aisprivate which is used to indicate the private nature of the operation. example function downloadfile(httploc, sourcewindow) { try { //new obj_uri object var obj_uri = components.classes["@mozilla.org/network/io-service;1"].getservice(components.interfaces.nsiioservice).newuri(httploc, null, null); //new file object var obj_t...

nsIWebProgress
to this article. last changed in gecko 1.8.0 inherits from: nsisupports method overview void addprogresslistener(in nsiwebprogresslistener alistener, in unsigned long anotifymask); void removeprogresslistener(in nsiwebprogresslistener alistener); attributes attribute type description domwindow nsidomwindow the dom window associated with this nsiwebprogress instance. read only. exceptions thrown ns_error_failure indicates that there is no associated dom window. isloadingdocument prbool indicates whether or not a document is currently being loaded in the context of this nsiwebprogress instance. read only. constants the following flags may be combined to form the anotifymask parameter for the addprogresslistener() method. they limit the set of events that are delivered to a...
... notifications. methods addprogresslistener() registers a listener to receive web progress events. void addprogresslistener( in nsiwebprogresslistener alistener, in unsigned long anotifymask ); parameters alistener the listener interface to be called when a progress event occurs. this object must also implement nsisupportsweakreference. anotifymask the types of notifications to receive. exceptions thrown ns_error_invalid_arg indicates that alistener was either null or that it does not support weak references. ns_error_failure indicates that alistener was already registered. removeprogresslistener() removes a previously registered listener of progress events. void removeprogresslistener( in nsiwebprogresslistener alistener ); parameters alistener the listener interface previously reg...
...listener was either null or that it does not support weak references. ns_error_failure indicates that alistener was already registered. removeprogresslistener() removes a previously registered listener of progress events. void removeprogresslistener( in nsiwebprogresslistener alistener ); parameters alistener the listener interface previously registered with a call to addprogresslistener(). exceptions thrown ns_error_failure indicates that alistener was not registered. ...

nsIXULTemplateQueryProcessor
ariable avar would be 7, assuming the query processor considers the syntax '+2' to mean add two to the reference. void addbinding( in nsidomnode arulenode, in nsiatom avar, in nsiatom aref, in astring aexpr ); parameters arulenode rule to add the binding to. avar variable that will be bound. aref variable that holds reference value. aexpr expression used to compute the value to assign. exceptions thrown ns_error_unexpected if generateresults() has already been called. compareresults() compare two results to determine their order, used when sorting results. this method should return -1 when the left result is less than the right, 0 if both are equivalent, and 1 if the left is greater than the right. the comparison should only consider the values for the specified variable. if the compar...
...y with different values for aref. nsisimpleenumerator generateresults( in nsisupports adatasource, in nsixultemplateresult aref, in nsisupports aquery ); parameters adatasource datasource for the data. aref context reference value used as a starting point. aquery the compiled query returned from query compilation. return value an enumerator of nsixultemplateresult objects as the results. exceptions thrown ns_error_invalid_arg if aquery is invalid. getdatasource() retrieve the datasource to use for the query processor. the list of datasources in a template is specified using the datasources attribute as a space separated list of uris. this list is processed by the builder and supplied to the query processor in the adatasources array as a list of nsiuri objects or nsidomnode objects. this ...
... whenever the template is rebuilt. this method must be called once before any of the other query processor methods except for translateref(). void initializeforbuilding( in nsisupports adatasource, in nsixultemplatebuilder abuilder, in nsidomnode arootnode ); parameters adatasource datasource for the data. abuilder the template builder. arootnode the root node the builder is attached to. exceptions thrown ns_error_invalid_arg if the datasource is not supported. ns_error_unexpected if generateresults() has already been called. translateref() translate a ref attribute string into a result. this is used as the reference point by the template builder when generating the first level of content. for recursive generation, the result from the parent generation phase will be used directly as the ...

nsIAbCard/Thunderbird3
his will be removed from the interface at a later date. methods getproperty() returns a property for the given name. nsivariant getproperty(in autf8string name, in nsivariant defaultvalue); parameters name the case-sensitive name of the property to get. defaultvalue the value to return if the property does not exist. return value the value of the attribute asked for. exceptions thrown ns_error_not_available<tt> if the named property does not exist. <tt>ns_error_cannot_convert_data if the property cannot be converted to the desired type. getpropertyasastring() getpropertyasautf8string() getpropertyasuint32() getpropertyasbool() [noscript] astring getpropertyasastring(in string name); [noscript] autf8string getpropertyasautf8string(in string name); [noscri...
...rue is a non-zero value), so that false will be converted to a string of 0 and not false<code>. these functions are marked <code>[noscript] since xpcconnect performs automatic type conversion on nsivariant such that they are not needed for scripts, only for c++ callers. parameters name the case-sensitive name of the property to get. return value the value of the attribute asked for. exceptions thrown ns_error_not_available<tt> if the named property does not exist. <tt>ns_error_cannot_convert_data if the property cannot be converted to the desired type. [noscript] astring getpropertyasastring(in string name); [noscript] autf8string getpropertyasautf8string(in string name); [noscript] pruint32 getpropertyasuint32(in string name); [noscript] boolean getpropertyasbool(in strin...
...leteproperty(in autf8string name); parameters name the case-sensitive name of the property to set. translateto() translates a card into a specific format. the following types are supported: base64xml xml vcard autf8string translateto(in autf8string atype); parameters atype the type of item to translate the card into. return value a string containing the translated card. exceptions thrown ns_error_illegal_value type not recognized. copy() this function will copy all values from one card to another. void copy(in nsiabcard srccard) parameters srccard the source card to copy values from. equals() returns true if this card is equal to the other card. the default implementation defines equal as this card pointing to the same object as acard. another implementat...

XPIDL
be thrown in script contexts and native contexts lack the set method, by using the "readonly" keyword. to native code, on attribute declared 'attribute type foo;' is syntactic sugar for the declaration of two methods 'type getfoo();' and 'void setfoo(in type foo);'. if foo were declared readonly, the latter method would not be present. attributes support all of the properties of methods with the exception of optional_argc, as this does not make sense for attributes. there are some special rules for attribute naming. as a result of vtable munging by the msvc++ compiler, an attribute with the name `iid' is forbidden. in addition, any attribute whose name matches the regex /^[a-z]{2,3}i[a-z][a-z]/ is emitted with a warning, as its name looks like an nsiinterface or a moziinterface declaration. also ...
...a scriptable interface and it lacks a noscript or notxpcom property. any method that is not scriptable can only be accessed by native code. however, scriptable methods must contain parameters and a return type that can be translated to script: any native type, save those declared with an nsid, utf8string, cstring, astring, or jsval property, may not be used in a scriptable method or attribute. an exception to the above rule is if the parameter has the iid_is property (a special case for some queryinterface-like operations). in general, this means that the only usable native types are those declared in nsrootidl.idl (see above). methods and attributes are mangled on conversion to native code. if a method is declared notxpcom, the mangling of the return type is prevented, so it is called mostly as i...
...ler. if optional_argc is present, then an additional uint8_t _argc method is added at the end which receives the number of optional arguments that were actually used (obviously, you need to have an optional argument in the first place). note that if both properties are set, the jscontext *cx is added first, followed by the uint8_t _argc, and then ending with return value parameter. finally, as an exception to everything already mentioned, for attribute getters and setters the jscontext *cx comes before any other arguments. another native-only property is nostdcall. normally, declarations are made in the stdcall abi on windows to be abi-compatible with com interfaces. any non-scriptable method or attribute with nostdcall instead uses the thiscall abi convention. methods without this property genera...

PointerType
pointertype represents c pointer. syntax returns a new ctype object describing a new pointer data type. ctype pointertype( type ); parameters type specifies the type to which the pointer type points. this can be any ctype object to declare the new type as a pointer to that type. return value a ctype object describing the newly created data type. exceptions thrown typeerror thrown if the parameter isn't a ctype. examples creating a type "pointer to 32-bit integer" looks like this: var intptrtype = new ctypes.pointertype(ctypes.int32_t); properties property type description targettype ctype the type of object the pointer points to. read only. properties inherited from ctype these properties are available on all ctype objects. ...
... ctype. return value a cdata representing the newly allocated pointer. pointertype cdata properties property type description contents cdata reading this property returns a cdata object referring to the pointed-to contents of the object. writing to this value writes the c conversion of the data into the pointed-to memory. ...
... pointertype cdata method_overview bool isnull() methods inherited from cdata cdata address() string tosource() string tostring() pointertype cdata methods isnull() determines whether or not the pointer's value is null. bool isnull(); parameters none. ...

Debugger.Environment - Firefox Developer Tools
the identifier with a variable, independently of its outer environments. we say an identifier isin scope in an environment if the identifier is bound in that environment or any enclosing environment. spidermonkey creates debugger.environment instances as needed as the debugger inspects stack frames and function objects; calling debugger.environment as a function or constructor raises a typeerror exception. spidermonkey creates exactly one debugger.environment instance for each environment it presents via a given debugger instance: if the debugger encounters the same environment through two different routes (perhaps two functions have closed over the same environment), spidermonkey presents the same debugger.environment instance to the debugger each time. this means that the debugger can use the =...
... unable to produce its value, it returns an ordinary javascript object (not a debugger.object instance) whose optimizedout property is true. this is not an invocation function; if this call would cause debuggee code to run (say, because the environment is a "with" environment, andname refers to an accessor property of the with statement’s operand), this call throws a debugger.debuggeewouldrun exception. setvariable(name,value) storevalue as the value of the variable bound toname in this environment.name must be a string that is a valid ecmascript identifier name;value must be a debuggee value. if this environment binds no variable namedname, throw a referenceerror. this is not an invocation function; if this call would cause debuggee code to run, this call throws a debugger.debuggeewo...
...tvariable(name,value) storevalue as the value of the variable bound toname in this environment.name must be a string that is a valid ecmascript identifier name;value must be a debuggee value. if this environment binds no variable namedname, throw a referenceerror. this is not an invocation function; if this call would cause debuggee code to run, this call throws a debugger.debuggeewouldrun exception. find(name) return a reference to the innermost environment, starting with this environment, that bindsname. ifname is not in scope in this environment, return null.name must be a string whose value is a valid ecmascript identifier name. source metadata generated from file: js/src/doc/debugger/debugger.environment.md watermark: sha256:3d6f67939e351803d5d7fe201ed38c4aaf766caf032f255...

Web Console remoting - Firefox Developer Tools
t. the pageerror packet is: { "from": "conn0.console9", "type": "pageerror", "pageerror": { "errormessage": "referenceerror: foo is not defined", "sourcename": "http://localhost/~mihai/mozilla/test.js", "linetext": "", "linenumber": 6, "columnnumber": 0, "category": "content javascript", "timestamp": 1347294508210, "error": false, "warning": false, "exception": true, "strict": false, "private": false, } } the packet is similar to nsiscripterror - for simplicity. we only removed several unneeded properties and changed how flags work. the private flag tells if the error comes from a private window/tab (added in firefox 24). starting with firefox 24 the errormessage and linetext properties can be long string actor grips if the string is ver...
... node is currently selected in the inspector, if any. this nodeactor can then be referred to by the $0 jsterm helper. the response packet: { "from": "conn0.console9", "input": "document", "result": { "type": "object", "classname": "htmldocument", "actor": "conn0.consoleobj20" "extensible": true, "frozen": false, "sealed": false }, "timestamp": 1347306273605, "exception": null, "exceptionmessage": null, "helperresult": null } exception holds the json-ification of the exception thrown during evaluation. exceptionmessage holds the exception.tostring() result. result has the result objectactor instance. helperresult is anything that might come from a jsterm helper result, json stuff (not content objects!). in firefox 23: we renamed the error and error...
...essage": null, "helperresult": null } exception holds the json-ification of the exception thrown during evaluation. exceptionmessage holds the exception.tostring() result. result has the result objectactor instance. helperresult is anything that might come from a jsterm helper result, json stuff (not content objects!). in firefox 23: we renamed the error and errormessage properties to exception and exceptionmessage respectively, to avoid conflict with the default properties used when protocol errors occur. autocomplete and more the autocomplete request packet: { "to": "conn0.console9", "type": "autocomplete", "text": "d", "cursor": 1 } the response packet: { "from": "conn0.console9", "matches": [ "decodeuri", "decodeuricomponent", "defaultstatus", "dev...

AudioNode.disconnect() - Web APIs
disconnected from, with any other, optional, parameters (output and/or input) further limiting which inputs and/or outputs should be disconnected. if this value is an audioparam, then the connection to that audioparam is terminated, and the node's contributions to that computed parameter become 0 going forward once the change takes effect. if no matching connection is found, an invalidaccesserror exception is thrown. output optional an index describing which output from the current audionode is to be disconnected. the index numbers are defined according to the number of output channels (see audio channels). if this parameter is out-of-bound, an indexsizeerror exception is thrown. input optional an index describing which input into the specified destination audionode is to be disconnected. the i...
... invalidaccesserror the node on which disconnect() was called isn't connected to the specified destination node. ...
... invalidaccesserror the node on which disconnect() was called isn't connected to the specified destination node. ...

CSSPrimitiveValue.getCounterValue() - Web APIs
this is not css_counter). ...
...this is not css_counter). ...
...this is not css_counter). ...

CSSPrimitiveValue.getRGBColorValue() - Web APIs
this is not css_rgbcolor). ...
...this is not css_rgbcolor). ...
...this is not css_rgbcolor). ...

CSSPrimitiveValue.getRectValue() - Web APIs
(i.e. this is not css_rect). ...
...(i.e. this is not css_rect). ...
...(i.e. this is not css_rect). ...

Console.error() - Web APIs
parameters obj1 ... objn a list of javascript objects to output. the string representations of each of these objects are appended together in the order listed and output. ...
... parameters obj1 ... objn a list of javascript objects to output. the string representations of each of these objects are appended together in the order listed and output. ...
... parameters obj1 ... objn a list of javascript objects to output. the string representations of each of these objects are appended together in the order listed and output. ...

HTMLMediaElement.setSinkId() - Web APIs
the htmlmediaelement.setsinkid() method sets the id of the audio device to use for output and returns a promise. this only works when the application is authorized to use the specified device. syntax htmlmediaelement.setsinkid(sinkid).then(function() { ... }) returns a promise that resolves to undefined. parameters sinkid the mediadeviceinfo.deviceid of the audio output device. ...
...element.setsinkid() method sets the id of the audio device to use for output and returns a promise. this only works when the application is authorized to use the specified device. syntax htmlmediaelement.setsinkid(sinkid).then(function() { ... }) returns a promise that resolves to undefined. parameters sinkid the mediadeviceinfo.deviceid of the audio output device. ...
... the audio device to use for output and returns a promise. this only works when the application is authorized to use the specified device. syntax htmlmediaelement.setsinkid(sinkid).then(function() { ... }) returns a promise that resolves to undefined. parameters sinkid the mediadeviceinfo.deviceid of the audio output device. ...

HTMLTableSectionElement - Web APIs
the valign attribute and can have one of the following values: "top", "middle", "bottom", or "baseline". methods inherits methods from its parent, htmlelement. htmltablesectionelement.deleterow() removes the cell at the given position in the section. ...
... specifications specification status comment html living standardthe definition of 'htmltablesectionelement' in that specification. living standard html5the definition of 'htmltablesectionelement' in that specification. recommendation the parameter of insertcell is now optional. ...
...ectionelement' in that specification. living standard html5the definition of 'htmltablesectionelement' in that specification. recommendation the parameter of insertcell is now optional. document object model (dom) level 2 html specificationthe definition of 'htmltablesectionelement' in that specification. obsolete the methods insertrow and deleterow can raise exceptions. document object model (dom) level 1 specificationthe definition of 'htmltablesectionelement' in that specification. obsolete initial definition. ...

Working with the History API - Web APIs
oo.html, and the document will get a popstate event, this time with a null state object. here too, going back doesn't change the document's contents from what they were in the previous step, although the document might update its contents manually upon receiving the popstate event. note: calling history.back() normally behaves the same way as clicking the back button. but there is one important exception: after using history.pushstate(), calling history.back() does not raise a popstate event. clicking the browser's back button (still) does. the pushstate() method pushstate() takes three parameters: a state object; a title (currently ignored); and (optionally), a url. let's examine each of these three parameters in more detail. state object the state object is a javascript object which i...
...ate object. the state object can be anything that can be serialized. because firefox saves state objects to the user's disk so they can be restored after the user restarts the browser, we impose a size limit of 640k characters on the serialized representation of a state object. if you pass a state object whose serialized representation is larger than this to pushstate(), the method will throw an exception. if you need more space than this, you're encouraged to use sessionstorage and/or localstorage. title all browsers but safari currently ignore this parameter, although they may use it in the future. passing the empty string here should be safe against future changes to the method. alternatively, you could pass a short title for the state to which you're moving. url the new history entry...
...given by this parameter. note that the browser won't attempt to load this url after a call to pushstate(), but it might attempt to load the url later, for instance after the user restarts the browser. the new url does not need to be absolute; if it's relative, it's resolved relative to the current url. the new url must be of the same origin as the current url; otherwise, pushstate() will throw an exception. this parameter is optional; if it isn't specified, it's set to the document's current url. note: in gecko 2.0 (firefox 4 / thunderbird 3.3 / seamonkey 2.1) through gecko 5.0 (firefox 5.0 / thunderbird 5.0 / seamonkey 2.2), the passed object is serialized using json. starting in gecko 6.0 (firefox 6.0 / thunderbird 6.0 / seamonkey 2.3), the object is serialized using the structured clone algori...

IDBCursorSync - Web APIs
you can have only one instance of idbcursorsync representing a cursor, but you can have an unlimited number of cursors at the same time. operations are performed on the underlying index or object store. it enables an application to synchronously process all the records in the cursor's range. method overview bool continue (in optional any key); void remove () raises (idbdatabaseexception); attributes attribute type description count readonly unsigned long long the total number of objects that share the current key. direction readonly unsigned short the direction of traversal of the cursor. see constants for possible values. key readonly any the key for the record at the cursor's position. value an...
... long the total number of objects that share the current key. direction readonly unsigned short the direction of traversal of the cursor. see constants for possible values. key readonly any the key for the record at the cursor's position. value any the value for the record at the cursor's position. setting this attribute can raise an idbdatabaseexception with the following codes: data_err if the underlying object store uses in-line keys and the property at the key path does not match the key in this cursor's position. not_allowed_err if the underlying index or object store does not support updating the record because it is open in the read_only or snapshot_read mode, or if an index record cannot be changed because the un...
...arameter. if no key is specified, advance to the immediate next position. returns false if the cursor has reached the end of its range; otherwise returns true. bool continue ( in optional any key ); parameters key the key to which to move the cursor's position. remove() deletes the record at the cursor's position, without changing the cursor's position void delete ( ) raises (databaseexception); exceptions this method can raise an idbdatabaseexception with the following code: not_allowed_err if the underlying index or object store does not support updating the record because it is open in the read_only or snapshot_read mode. ...

IDBFactorySync - Web APIs
its need was questionable. it may however be reintroduced in the future if there is enough demand from web developers. the idbfactorysync interface of the indexeddb api provide a synchronous means of accessing the capabilities of indexed databases. ...
...a valid name is any string including the empty string. ...
...tabase with the specified name, it uses that one; otherwise, it creates the database using the specified name and description. idbdatabasesync open ( in domstring name, in domstring description ) raises (idbdatabaseexception); parameters name the name for the database. description the description for the database. returns idbdatabasesync an object to access the open database. exceptions this method can raise an idbdatabaseexception with the following codes: non_transient_err if the name parameter is not valid. a valid name is any string including the empty string. unknown_err if an error occurs while the database is being opened. ...

IDBRequest.error - Web APIs
the error read-only property of the idbrequest interface returns the error in the event of an unsuccessful request. note: this feature is available in web workers. syntax var myerror = request.error; value a domerror containing the relevant error. in chrome 48+/firefox 58+ this property returns a domexception because domerror has been removed from the dom standard. the following error codes are returned under certain conditions: error explanation aborterror if you abort the transaction, then all requests still in progress receive this error. constrainterror if you insert data that doesn't conform to a constraint. it's an exception type for creating stores and indexes. you get this error, for example, if you try to add a new key that already exists in...
... unknownerror if the operation failed for reasons unrelated to the database itself. a failure due to disk io errors is such an example. noerror if the request succeeds. versionerror if you try to open a database with a version lower than the one it already has. in addition to the error codes sent to the idbrequest object, asynchronous operations can also raise exceptions. the list describes problems that could occur when the request is being executed, but you might also encounter other problems when the request is being made. for example, if the the request failed and the result is not available, the invalidstateerror exception is thrown. example the following example requests a given record title, onsuccess gets the associated record from the idbobjectstore (...
...a android full support 14safari ios full support 8samsung internet android full support 1.5 full support 1.5 no support 1.5 — 7.0prefixed prefixed implemented with the vendor prefix: webkitdomexception value instead of domerrorchrome full support 48edge full support ≤18firefox full support 58ie no support noopera full support yessafari no support ...

IDBRequest - Web APIs
operations immediately return an idbrequest instance. each request has a readystate that is set to the 'pending' state; this changes to 'done' when the request is completed or fails. when the state is set to done, every request returns a result and an error, and an event is fired on the request. when the state is still pending, any attempt to access the result or error raises an invalidstateerror exception. ...
... the interface idbopendbrequest is derived from idbrequest. note: this feature is available in web workers. ...
...="#f4f7f8" stroke="#d4dde4" stroke-width="2px" /><text x="201" y="30" font-size="12px" font-family="consolas,monaco,andale mono,monospace" fill="#4d4e53" text-anchor="middle" alignment-baseline="middle">idbrequest</text></a></svg></div> a:hover text { fill: #0095dd; pointer-events: all;} properties also inherits properties from eventtarget. idbrequest.error read only returns a domexception in the event of an unsuccessful request, indicating what went wrong. idbrequest.result read only returns the result of the request. if the the request failed and the result is not available, an invalidstateerror exception is thrown. idbrequest.source read only the source of the request, such as an idbindex or an idbobjectstore. if no source exists (such as when calling idbfactory.open),...

LocalFileSystemSync - Web APIs
ed (in bytes) // initfs is the success callback // and the last one is the error callback // for denial of access and other errors. var fs = requestfilesystemsync(temporary, 1024*1024 /*1mb*/); because you are using a synchronous api, you don't need success and error callbacks. method overview filesystemsync requestfilesystemsync (in unsigned short type, in long long size) raises fileexception; entrysync resolvelocalfilesystemsyncurl (in domstring url) raises fileexception; constants constant value description temporary 0 transient storage that can be be removed by the browser at its discretion. persistent 1 storage that stays in the browser unless the user or the app expunges it. methods requestfilesys...
...l method, window.requestfilesystemsync(). [ research ] filesystemsync requestfilesystemsync( in unsigned short type, in unsigned long long size ); parameters type the storage type of the file system. the values can be either temporary or persistent. size the storage space—in bytes—that you need for your app. returns filesystemsync an object that represents the file system. exceptions this method can raise an fileexception with the following code: exception description security_error the application does not have permission to access the file system interface. for example, you cannot run from file://. for more details, see the article on basic concepts. resolvelocalfilesystemsyncurl() allows the user to look up the entry for a file or directo...
...t run from file://. for more details, see the article on basic concepts. resolvelocalfilesystemsyncurl() allows the user to look up the entry for a file or directory referred to by a local url. void resolvelocalfilesystemurl( in domstring url ); parameter url the url of a local file in the file system. returns entrysync an object that represents entries in the file system. exceptions this method can raise a fileexception with the following codes: exception description encoding_err the syntax of the url was invalid. not_found_err the url was structurally correct, but refers to a resource that does not exist. security_err the application does not have permission to access the file system interface. browser compatibil...

MediaRecorder.onerror - Web APIs
the mediarecorder interface's onerror event handler is called by the mediastream recording api when an error occurs. you can provide an event handler to deal with errors that occur while creating or using a media recorder. the error object is of type mediarecordererrorevent, and its error property contains a domexception object that describes the error that occurred. syntax mediarecorder.onerror = errorhandlerfunction; value a function to be called whenever an error occurs during the recorder's lifetime. in addition to other general errors that might occur, the following errors are specifically possible when using the mediastream recording api; to determine which occurred, check the value of mediarecordererrorevent.error.name. invalidstateerror an attempt was made to stop or pause or an i...
... general errors that might occur, the following errors are specifically possible when using the mediastream recording api; to determine which occurred, check the value of mediarecordererrorevent.error.name. invalidstateerror an attempt was made to stop or pause or an inactive recorder, start or resume an active recorder, or otherwise manipulate the mediarecorder while in the wrong state. this exception can also occur when a request is made on a source that has been deleted or removed. securityerror the mediastream is configured to disallow recording. this may be the case, for example, with sources obtained using getusermedia() when the user denies permission to use an input device. this also happens when a mediastreamtrack within the stream is marked as isolated due to the peeridentity const...
...a, and finally a stop event is sent. these errors may occur either directly because of a call to a mediarecorder method, or indirectly due to a problem arising during the recording process. example this example creates a new mediarecorder instance and starts recording using the user agent's default media format. it returns either the mediarecorder or the name of the error that occurred if any exceptions are thrown during the setup process. function recordstream(stream) { let recorder = null; let bufferlist = []; try { recorder = new mediarecorder(stream); } catch(err) { return err.name; /* return the error name */ } recorder.ondataavailable = function(event) { bufferlist.push(event.data); }; recorder.onerror = function(event) { let error = event.error; ...

Node.removeChild() - Web APIs
r code, via the oldchild object reference. in the second syntax form, however, there is no oldchild reference kept, so assuming your code has not kept any other reference to the node elsewhere, it will immediately become unusable and irretrievable, and will usually be automatically deleted from memory after a short time. if child is actually not a child of the element node, the method throws an exception. ...
...trievable, and will usually be automatically deleted from memory after a short time. if child is actually not a child of the element node, the method throws an exception. ...
... an exception. this will also happen if child was in fact a child of element at the time of the call, but was removed by an event handler invoked in the course of trying to remove the element (e.g., blur.) errors thrown the method throws an exception in 2 different ways: if the child was in fact a child of element and so existing on the dom, but was removed the method throws the following exception: uncaught notfounderror: failed to execute 'removechild' on 'node': the node to be removed is not a child of this node. if the child doesn't exist on the dom of the page, the method throws the following exception: uncaught typeerror: failed to execute 'removechild' on 'node': parameter 1 is not of type 'node'. examples simple examples given this html: <div id="top"> <div ...

SVGMarkerElement - Web APIs
tribute orient; otherwise, it will be set to zero. methods this also inherits methods from its parent, svgelement, and implements properties from svgstylable. setorienttoangle(in svgangle angle) void sets the value of attribute orient to the given angle. ...
... to zero. methods this also inherits methods from its parent, svgelement, and implements properties from svgstylable. setorienttoangle(in svgangle angle) void sets the value of attribute orient to the given angle. ...
... sets the value of attribute orient to the given angle. exceptions: a domexception with code no_modification_allowed_err is raised when the object itself is read only. setorienttoauto() void sets the value of attribute orient to 'auto'. exceptions: a domexception with code no_modification_allowed_err is raised when the object itself is read only. browser compatibility desktop mobile chrome edge firefox interne...

TextDecoder() - Web APIs
syntax decoder = new textdecoder(utflabel, options); parameters utflabeloptional is a domstring, defaulting to "utf-8", containing the label of the encoder. ...
... specifications...
...nary with the property: fatal a boolean flag indicating if the textdecoder.decode() method must throw a domexception with the "encodingerror" value when an coding error is found. it defaults to false. example var textdecoder1 = new textdecoder("iso-8859-2"); var textdecoder2 = new textdecoder(); var textdecoder3 = new textdecoder("csiso2022kr", {fatal: true}); // allows encodingerror exception to be thrown. var textdecoder4 = new textdecoder("iso-2022-cn"); // throw a typeerror exception. specifications specification status comment encodingthe definition of 'textdecoder()' in that specification. living standard initial definition. ...

URL() - Web APIs
the url() constructor returns a newly created url object representing the url defined by the parameters. if the given base url or the resulting url are not valid urls, the javascript typeerror exception is thrown. note: this feature is available in web workers. syntax const url = new url(url [, base]) parameters url a usvstring representing an absolute or relative url. if url is a relative url, base is required, and will be used as the base url. if url is an absolute url, a given base will be ignored. base optional a usvstring representing the base url to use in case url is a relative url. ...
...relative url. if url is a relative url, base is required, and will be used as the base url. if url is an absolute url, a given base will be ignored. base optional a usvstring representing the base url to use in case url is a relative url. if not specified, it defaults to ''. note: you can still use an existing url object for the base, which stringifies itself to the object's href property. exceptions exception explanation typeerror url (in the case of absolute urls) or base + url (in the case of relative urls) is not a valid url. examples // base urls let m = 'https://developer.mozilla.org'; let a = new url("/", m); // => 'https://developer.mozilla.org/' let b = new url(m); // => 'https://...
...cs' new url('/docs', a); // => 'https://developer.mozilla.org/docs' new url('/docs', "https://developer.mozilla.org/fr-fr/toto"); // => 'https://developer.mozilla.org/docs' new url('/docs', ''); // raises a typeerror exception as '' is not a valid url new url('/docs'); // raises a typeerror exception as '/docs' is not a valid url new url('http://www.example.com', ); // => 'http://www.example.com/' new url('http://www.example.com', b); // => 'http://www.example.com/' new url("//foo.com", "https://example.com") // => 'https://foo.com' (see rela...

Writing a WebSocket server in Java - Web APIs
ie 10 and higher. first steps websockets communicate over a tcp (transmission control protocol) connection. java's serversocket class is located in the java.net package. serversocket constructor: serversocket(int port) when you instantiate the serversocket class, it is bound to the port number you specified by the port argument. ...
...uctor: serversocket(int port) when you instantiate the serversocket class, it is bound to the port number you specified by the port argument. ...
...io.ioexception; import java.io.inputstream; import java.io.outputstream; import java.net.serversocket; import java.net.socket; import java.security.messagedigest; import java.security.nosuchalgorithmexception; import java.util.base64; import java.util.scanner; import java.util.regex.matcher; import java.util.regex.pattern; public class websocket { public static void main(string[] args) throws ioexception, nosuchalgorithmexception { serversocket server = new serversocket(80); try { system.out.println("server has started on 127.0.0.1:80.\r\nwaiting for a connection..."); socket client = server.accept(); system.out.println("a client connected."); socket methods: java.net.socket getinputstream() returns an input stream for this socket. java.net.socket getoutputstream() returns ...

Using Web Workers - Web APIs
at are utilized by a single script; shared workers use sharedworkerglobalscope). a dedicated worker is only accessible from the script that first spawned it, whereas shared workers can be accessed from multiple scripts. note: see the web workers api landing page for reference documentation on workers and additional guides. you can run whatever code you like inside the worker thread, with some exceptions. for example, you can't directly manipulate the dom from inside a worker, or use some default methods and properties of the window object. but you can use a large number of items available under window, including websockets, and data storage mechanisms like indexeddb. see functions and classes available to workers for more details. data is sent between workers and the main thread via a system o...
...ir messages using the postmessage() method, and respond to messages via the onmessage event handler (the message is contained within the message event's data attribute.) the data is copied rather than shared. workers may, in turn, spawn new workers, as long as those workers are hosted within the same origin as the parent page. in addition, workers may use xmlhttprequest for network i/o, with the exception that the responsexml and channel attributes on xmlhttprequest always return null. dedicated workers as mentioned above, a dedicated worker is only accessible by the script that called it. in this section we'll discuss the javascript found in our basic dedicated worker example (run dedicated worker): this allows you to enter two numbers to be multiplied together. the numbers are sent to a dedica...
...content-security-policy: script-src 'self' among other things, this will prevent any scripts it includes from using eval(). however, if the script constructs a worker, code running in the worker's context will be allowed to use eval(). to specify a content security policy for the worker, set a content-security-policy response header for the request which delivered the worker script itself. the exception to this is if the worker script's origin is a globally unique identifier (for example, if its url has a scheme of data or blob). in this case, the worker does inherit the csp of the document or worker that created it. transferring data to and from workers: further details data passed between the main page and workers is copied, not shared. objects are serialized as they're handed to the worke...

XPathEvaluator.evaluate() - Web APIs
evaluating the expression. this must be one of the xpathresult.constants. result optional allows to specify a result object which may be reused and returned by this method. if this is specified as null or the implementation does not reuse the specified result, a new result object will be returned. return value an xpathresult object representing the result of evaluating the xpath expression. exceptions invalid_expression_err if the expression is not legal according to the rules of the xpathevaluator, an xpathexception of type invalid_expression_err is raised. type_err in case result cannot be converted to the specified type, an xpathexception of type type_err is raised. namespace_err if the expression contains namespace prefixes which cannot be resolved by the specified xpathnsresolver, ...
...valid_expression_err if the expression is not legal according to the rules of the xpathevaluator, an xpathexception of type invalid_expression_err is raised. type_err in case result cannot be converted to the specified type, an xpathexception of type type_err is raised. namespace_err if the expression contains namespace prefixes which cannot be resolved by the specified xpathnsresolver, a domexception of type namespace_error is raised. wrong_document_err if the provided context node is from a document that is not supported by the xpathevaluator, a domexception of type wrong_document_err is raised. ...
... example the following example shows the use of the evaluate() method. ...

XPathExpression.evaluate() - Web APIs
evaluating the expression. this must be one of the xpathresult.constants. result optional allows to specify a result object which may be reused and returned by this method. if this is specified as null or the implementation does not reuse the specified result, a new result object will be returned. return value an xpathresult object representing the result of evaluating the xpath expression. exceptions invalid_expression_err if the expression is not legal according to the rules of the xpathevaluator, an xpathexception of type invalid_expression_err is raised. type_err in case result cannot be converted to the specified type, an xpathexception of type type_err is raised. namespace_err if the expression contains namespace prefixes which cannot be resolved by the specified xpathnsresolver, ...
...valid_expression_err if the expression is not legal according to the rules of the xpathevaluator, an xpathexception of type invalid_expression_err is raised. type_err in case result cannot be converted to the specified type, an xpathexception of type type_err is raised. namespace_err if the expression contains namespace prefixes which cannot be resolved by the specified xpathnsresolver, a domexception of type namespace_error is raised. wrong_document_err if the provided context node is from a document that is not supported by the xpathevaluator, a domexception of type wrong_document_err is raised. ...
... example the following example shows the use of the evaluate() method. ...

Specificity - CSS: Cascading Style Sheets
e no effect on specificity. (the selectors declared inside :not() do, however.) for more information, visit: "specificity" in "cascade and inheritance", you can also visit: https://specifishity.com inline styles added to an element (e.g., style="font-weight: bold;") always overwrite any styles in external stylesheets, and thus can be thought of as having the highest specificity. the !important exception when an important rule is used on a style declaration, this declaration overrides any other declarations. although technically !important has nothing to do with specificity, it interacts directly with it. using !important, however, is bad practice and should be avoided because it makes debugging more difficult by breaking the natural cascading in your stylesheets. when two conflicting declaratio...
...but selectors placed into the pseudo-class count as normal selectors when determining the count of selector types. this chunk of css ... div.outer p { color: orange; } div:not(.outer) p { color: blueviolet; } ... when used with the following html ...
...ormal selectors when determining the count of selector types. this chunk of css ... div.outer p { color: orange; } div:not(.outer) p { color: blueviolet; } ... when used with the following html ... <div class="outer"> <p>this is in the outer div.</p> <div class="inner"> <p>this text is in the inner div.</p> </div> </div> ... appears on the screen like this: the :where() exception the specificity-adjustment pseudo-class :where() always has its specificity replaced with zero. this chunk of css ... div:where(.outer) p { color: orange; } div p { color: blueviolet; } #no-where-support { margin: 0.5em; border: 1px solid red; } #no-where-support:where(*) { display: none !important; } ... when used with the following html ... <div id="no-where-suppor...

Browser detection using the user agent - HTTP
. see the mobile device detection section for more information. another such case is for fixing bugs in browsers that do not automatically update. internet explorer (on windows) and webkit (on ios) are two perfect examples. prior to version 9, internet explorer had unbelievable issues with rendering bugs, css bugs, api bugs, and so forth. however, internet explorer was such a special little wasp exception prior to version 9 that it was very easy to detect the browser based upon the browser-specific features available. webkit is a bit worse because apple forces all of the browsers on ios to use webkit internally, thus the user has no way to get a better more updated browser on older devices. most bugs can be detected, but some bugs take more effort to detect than others. in such cases, it might be ...
...y actually want "rendering engine detection". do you actually want to detect firefox, as opposed to seamonkey, or chrome as opposed to chromium? or do you actually simply want to see if the browser is using the gecko or the webkit rendering engine? if this is what you need, see further down the page. most browsers set the name and version in the format browsername/versionnumber, with the notable exception of internet explorer. but as the name is not the only information in a user agent string that is in that format, you can not discover the name of the browser, you can only check if the name you are looking for. but note that some browsers are lying: chrome for example reports both as chrome and safari. so to detect safari you have to check for the safari string and the absence of the chrome strin...
... string edgehtml edge/xyz the non-chromium edge puts its engine version after the edge/ token, not the application version. note: edgehtml is no longer used in edge browser builds >= version 79 (see 'blink'). blink chrome/xyz rendering engine version most rendering engines put the version number in the renderingengine/versionnumber token, with the notable exception of gecko. gecko puts the gecko version number in the comment part of the user agent after the rv: string. from gecko 14 for the mobile version and gecko 17 for the desktop version, it also puts this value in the gecko/version token (previous version put there the build date, then a fixed date called the geckotrail). os the operating system is given in most user agent strings (although not web-f...

Proxy Auto-Configuration (PAC) file - HTTP
xy w3proxy.mozilla.org:8080; direct"; } } note: this is the simplest and most efficient autoconfig file for cases where there's only one proxy. ...
...be careful to note the parentheses around the or expression before the and expression to achieve the above-mentioned efficient behaviour. example 3 use prox...
...lla.org") && !localhostordoaminis(host, "merchant.mozilla.org") ) { return "direct"; } else { return "proxy w3proxy.mozilla.org:8080; direct"; } } the above example will use the proxy for everything except local hosts in the mozilla.org domain, with the further exception that hosts www.mozilla.org and merchant.mozilla.org will go through the proxy. note the order of the above exceptions for efficiency: localhostordomainis() functions only get executed for urls that are in local domain, not for every url. be careful to note the parentheses around the or expression before the and expression to achieve the above-mentioned efficient behaviour. example 3 use proxy only if cannot resolve host this example will work in an environment where the internal dns server is set up so that...

Meta programming - JavaScript
reported as existent if it does not exists as an own property of target and target is not extensible. a property cannot be reported as non-configurable if it does not exist as an own property of target or if it exists as a configurable own property of target. the result of object.getownpropertydescriptor(target) can be applied to target using object.defineproperty and will not throw an exception. handler.defineproperty() object.defineproperty() reflect.defineproperty() a property cannot be added if target is not extensible. a property cannot be added as (or modified to be) non-configurable if it does not exist as a non-configurable own property of target. a property may not be non-configurable if a corresponding configurable property of ta...
...rget is not extensible. a property cannot be added as (or modified to be) non-configurable if it does not exist as a non-configurable own property of target. a property may not be non-configurable if a corresponding configurable property of target exists. if a property has a corresponding target object property, then object.defineproperty(target, prop, descriptor) will not throw an exception. in strict mode, a false value returned from the defineproperty handler will throw a typeerror exception. handler.has() property query foo in proxy inherited property query foo in object.create(proxy) reflect.has() a property cannot be reported as non-existent, if it exists as a non-configurable own property of target...
...e different from the value of the corresponding target property if the corresponding target property is a non-writable, non-configurable data property. cannot set the value of a property if the corresponding target property is a non-configurable accessor property that has undefined as its [[set]] attribute. in strict mode, a false return value from the set handler will throw a typeerror exception. handler.deleteproperty() property deletion delete proxy[foo] delete proxy.foo reflect.deleteproperty() a property cannot be deleted if it exists as a non-configurable own property of target. handler.enumerate() property enumeration / for...in: for (let name in proxy) {...} reflect.enumerate() ...

Inheritance and the prototype chain - JavaScript
ck its prototype. // is there a 'd' own property on o.[[prototype]]? no, check its prototype. // o.[[prototype]].[[prototype]] is object.prototype and there is no 'd' property by default, check its prototype. // o.[[prototype]].[[prototype]].[[prototype]] is null, stop searching, // no property found, return undefined. code link setting a property to an object creates an own property. the only exception to the getting and setting behavior rules is when there is an inherited property with a getter or a setter. inheriting "methods" javascript does not have "methods" in the form that class-based languages define them. in javascript, any function can be added to an object in the form of a property. an inherited function acts just as any other property, including property shadowing as shown above (...
...he enter/return key. (the console is included in most web browser's developer tools. more information is available for firefox developer tools, chrome devtools, and edge devtools.) function dosomething(){} console.log( dosomething.prototype ); // it does not matter how you declare the function, a // function in javascript will always have a default // prototype property. // (ps: there is one exception that arrow function doesn't have a default prototype property) var dosomething = function(){}; console.log( dosomething.prototype ); as seen above, dosomething() has a default prototype property, as demonstrated by the console. after running this code, the console should have displayed an object that looks similar to this. { constructor: ƒ dosomething(), __proto__: { construct...
... var inst = { __proto__: { bar_prop: "bar val", __proto__: { foo_prop: "foo val", __proto__: object.prototype } } }; console.log(inst.foo_prop); console.log(inst.bar_prop) support in all in-use-today browsers which are all non-microsoft browsers plus ie11 and up. setting __proto__ to something that is not an object only fails silently. it does not throw an exception. grossly deprecated and non-performant. making your javascript run fast is completely out of the question if you dare use this in the final production code because many browsers optimize the prototype and try to guess the location of the method in the memory when calling an instance in advance, but setting the prototype dynamically disrupts all these optimizations and can even force some brows...

EvalError() constructor - JavaScript
however, the object itself remains for backwards compatibility with earlier versions of the specification. ...
...however, the object itself remains for backwards compatibility with earlier versions of the specification. ...
...however, the object itself remains for backwards compatibility with earlier versions of the specification. ...

Introduction to using XPath in JavaScript - XPath
h expressions and the possibly different prefixes used in the document. the function can be either: created by using the creatensresolver method of a xpathevaluator object. you should use this virtually all of the time. null, which can be used for html documents or when no namespace prefixes are used. note that, if the xpathexpression contains a namespace prefix, this will result in a domexception being thrown with the code namespace_err. a custom user-defined function. see the using a user defined namespace resolver section in the appendix for details. resulttype: a constant that specifies the desired result type to be returned as a result of the evaluation. the most commonly passed constant is xpathresult.any_type which will return the results of the xpath expression as the most...
... node-set types the xpathresult object allows node-sets to be returned in 3 principal different types: iterators snapshots first nodes iterators when the specified result type in the resulttype parameter is either: unordered_node_iterator_type ordered_node_iterator_type the xpathresult object returned is a node-set of matched nodes which will behave...
...contained by using the iteratenext() method of the xpathresult. once we have iterated over all of the individual matched nodes, iteratenext() will return null. note however, that if the document is mutated (the document tree is modified) between iterations that will invalidate the iteration and the invaliditeratorstate property of xpathresult is set to true, and a ns_error_dom_invalid_state_err exception is thrown. iterator example var iterator = document.evaluate('//phonenumber', documentnode, null, xpathresult.unordered_node_iterator_type, null ); try { var thisnode = iterator.iteratenext(); while (thisnode) { alert( thisnode.textcontent ); thisnode = iterator.iteratenext(); } } catch (e) { alert( 'error: document tree modified during iteration ' + e ); } snapshots when ...

selection - Archive of obsolete content
"\\\" + selection.html + "///"; }); globals properties text gets or sets the current selection as plain text. setting the selection removes all current selections, inserts the specified text at the location of the first selection, and selects the new text. getting the selection when there is no current selection returns null. setting the selection when there is no current selection throws an exception. getting the selection when iscontiguous is true returns the text of the first selection. html gets or sets the current selection as html. setting the selection removes all current selections, inserts the specified text at the location of the first selection, and selects the new text. getting the selection when there is no current selection returns null. setting the selection when there is no c...
...n iscontiguous is true returns the text of the first selection. html gets or sets the current selection as html. setting the selection removes all current selections, inserts the specified text at the location of the first selection, and selects the new text. getting the selection when there is no current selection returns null. setting the selection when there is no current selection throws an exception. getting the selection when iscontiguous is true returns the text of the first selection. iscontiguous true if the current selection is a single, contiguous selection, and false if there are two or more discrete selections, each of which may or may not be spatially adjacent. (discontiguous selections can be created by the user with ctrl+click-and-drag.) events select this event is emitted wh...

url - Archive of obsolete content
constructors url(source, base) the url constructor creates an object that represents a url, verifying that the provided string is a valid url in the process. any api in the sdk which has a url parameter will accept url objects, not raw strings, unless otherwise noted. parameters source : string a string to be converted into a url. if source is not a valid uri, this constructor will throw an exception. base : string an optional string used to resolve relative source urls into absolute ones. dataurl(uri) the dataurl constructor creates an object that represents a data: url, verifying that the provided string is a valid data: url in the process. parameters uri : string a string to be parsed as data url. if is not a valid uri, this constructor will throw an exception. functions tofilenam...
... parameters url : string the url, as a string, to be converted. returns string : the converted native file path as a string. ...

io/byte-streams - Archive of obsolete content
the backing stream, an nsiinputstream. bytewriter(outputstream) creates a binary output stream that writes bytes to a backing stream. you can also create bytewriter objects using io/file's open() function. parameters outputstream : stream the backing stream, an nsioutputstream. bytereader methods close() closes both the stream and its backing stream. if the stream is already closed, an exception is thrown. read(numbytes) reads a string from the stream. if the stream is closed, an exception is thrown. parameters numbytes : number the number of bytes to read. if not given, the remainder of the entire stream is read. returns string : a string containing the bytes read. if the stream is at the end, returns the empty string. properties closed true if the stream is closed. bytewrite...
...rown. parameters numbytes : number the number of bytes to read. if not given, the remainder of the entire stream is read. returns string : a string containing the bytes read. if the stream is at the end, returns the empty string. properties closed true if the stream is closed. bytewriter methods close() closes both the stream and its backing stream. if the stream is already closed, an exception is thrown. write(str) writes a string to the stream. if the stream is closed, an exception is thrown. parameters str : string the string to write. properties closed true if the stream is closed. ...

util/deprecate - Archive of obsolete content
experimental functions to deprecate code. globals functions deprecatefunction(fun, msg) dump to the console the error message given in the second argument, prefixed with "deprecated:", and print the stacktrace; then execute the function passed as first argument and returns its value. it does not raise an exception, but just displays the error message and continues to execute the function. this function is mostly used to flag usage of deprecated functions, that are still available but which we intend to remove in a future release. parameters fun : function the function to execute after the error message msg : string the error message to display returns * : the returned value from fun deprecateusage(msg) dump to the console the error message given, prefixed with "deprecated:", and ...
...cated functions, that are still available but which we intend to remove in a future release. parameters fun : function the function to execute after the error message msg : string the error message to display returns * : the returned value from fun deprecateusage(msg) dump to the console the error message given, prefixed with "deprecated:", and print the stacktrace. it does not raise an exception, but just displays the error message and returns. this function is mostly used to flag usage of deprecated functions that are no longer available. parameters msg : string the error message to display ...

Chrome Authority - Archive of obsolete content
ay be able to sneak around these restrictions). the manifest is built with a simple regexp-based scanner, not a full javascript parser. developers should stick to simple require statements, with a single static string, one per line of code. if the scanner fails to see a require entry, the manifest will not include that entry, and (once the implementation is complete) the runtime code will get an exception. ...
...r, not a full javascript parser. developers should stick to simple require statements, with a single static string, one per line of code. if the scanner fails to see a require entry, the manifest will not include that entry, and (once the implementation is complete) the runtime code will get an exception. ...

JavaScript Debugger Service - Archive of obsolete content
ook = { onexecute: function(frame, type, rv) { // your function here } }; jsd.enumeratescripts({ // the enumeratescript method will be called once for every script jsd knows about enumeratescript: function(script) { // your function here } }); a simple stack trace here, we will show how to implement a simple javascript stack trace using the jsd. note that onerror is called for every exception. jsd.errorhook = { onerror: function(message, filename, lineno, colno, flags, errnum, exc) { dump(message + "@" + filename + "@" + lineno + "@" + colno + "@" + errnum + "\n"); // check message type var jsdierrorhook = components.interfaces.jsdierrorhook; var messagetype; if (flags & jsdierrorhook.report_error) messagetype = "error"; if (flags & jsdierrorhook.report_warning...
..., colno, flags, errnum, exc) { dump(message + "@" + filename + "@" + lineno + "@" + colno + "@" + errnum + "\n"); // check message type var jsdierrorhook = components.interfaces.jsdierrorhook; var messagetype; if (flags & jsdierrorhook.report_error) messagetype = "error"; if (flags & jsdierrorhook.report_warning) messagetype = "warning"; if (flags & jsdierrorhook.report_exception) messagetype = "uncaught-exception"; if (flags & jsdierrorhook.report_strict) messagetype += "-strict"; dump(messagetype + "\n"); return false; // trigger debughook // return true; if you do not wish to trigger debughook } }; // note that debughook does not _always_ trigger when jsd.errorhook[onerror] returns false // it is not well-known why debughook sometimes fails to trigg...

The Essentials of an Extension - Archive of obsolete content
chrome://mozapps/content/downloads/downloads.xul on your location bar and press enter. surprised? you just opened the downloads window in a firefox tab! you can access any chrome file by just typing its uri in the location bar. this can come in handy if you want to inspect script files that are part of firefox, other extensions, or your own. most of these files are opened as text files, with the exception of xul files, which are executed and displayed like you would normally see them on a window. content there are 2 files in the content directory. let's look at the xul file first. xul files are xml files that define the user interface elements in firefox and firefox extensions. xul was inspired by html, so you'll see many similarities between the two. however, xul is also an improvement over ht...
...length is not having lines longer than 80 characters. this feels very restrictive, specially with xml files, but the number was chosen to allow pretty much any text editor to handle these files easily. even old command line editors work well with files that cut their lines at 80 characters. the tabulation is very straightforward: 2 blank space indents. we never use actual tab characters, with the exception of makefiles, which will be covered later on. most of our coding standards are based on mozilla's or other known and used standards. we'll skip some code that is covered in the locale section, moving on to the most important part of the content: <menubar id="main-menubar"> <menu id="xulschoolhello-hello-menu" label="&xulschoolhello.hello.label;" accesskey="&xulschoolhello.hellomenu.ac...

cert_override.txt - Archive of obsolete content
the syntax is described on this web site. example here is an example for a sha1-256 hash algorithm. the key and the website are not valid: # psm certificate override settings file # this is a generated file! do not edit. ...
...the syntax is described on this web site. example here is an example for a sha1-256 hash algorithm. the key and the website are not valid: # psm certificate override settings file # this is a generated file! do not edit. ...

Using Breakpoints in Venkman - Archive of obsolete content
zero, non-undefined, and non-false value will do), execution will continue normally. if, on the other hand, the script returns a false value, venkman will stop execution at that point. early return from caller with result will cause the function that the breakpoint is set in to return the value of the breakpoint script as its result, immediatley after the breakpoint script completes. ...
..., execution will continue normally. if, on the other hand, the script returns a false value, venkman will stop execution at that point. early return from caller with result will cause the function that the breakpoint is set in to return the value of the breakpoint script as its result, immediatley after the breakpoint script completes. the pass exceptions to caller checkbox allows you to pass exceptions thrown by the breakpoint script directly to the caller. normally, if the breakpoint script generates an exception, venkman assumes you made a mistake and stops execution after displaying the exception. if you would like to see what your code does when exceptions are thrown at it, check "pass exceptions to caller", and thrown an exception from the breakpoint script. the log result checkbox tell...

Introduction to XUL - Archive of obsolete content
e documents describing those particular applications. check the xptoolkit index for the most recent list. since xul is a language for describing window layout, there is some overlap in the topics covered by this document and a separate document describing xul windows. the task of writing a xul window description is basically the same as the task of writing an html content description, with these exceptions: the syntax is xml (not that different from html 4), and there are some elements unique to xul. these elements are widgets and certain infrastructure associated with the behaviour of the window, explained below. most of the details of writing a xul document are identical to those for writing an xml document, a description of which we will leave to other excellent xml documentation which we assu...
...ll want to store xul in *.xul files. a xul file can contain xml elements and html elements, as well as special elements unique to xul: xul elements. namespace declarations for xul (and html, if html elements are used) must be included in the file. namespaces must be treated carefully. correct namespace usage dictates that the namespace be used only for the tag, not in individual attributes. rare exceptions to this rule are bugs. xul file preamble xul is xml, and a good xul file begins with the standard xml version and doctype statements. since xml has no implicit display semantics, there must always be associated stylesheets. mozilla includes a standard stylesheet, "xul.css". you can load as many style sheets as you wish using repeated processing directives, although you should always make sure...

Writing Skinnable XUL and CSS - Archive of obsolete content
xplicitly. this is done using an @import directive placed at the top of the file. @import url(chrome://global/skin/) ... rest of skin file ... css files for a skin fall into two categories: base skin files and derived skin files. css files that import another skin file are calledderived skin files. css files that don't import another skin file are calledbase skin files. there is one notable exception to this rule. skin files that don't import any other skin files, but that are only intended to be used in the context of another component's skin are also considered derived skin files, since they are implicitly importing information from the other component's skin. these sorts of files are typically used with reusable overlayable widgets (e.g., the sidebar). your css file should never import an...
...or this button. it should only describe the icon. because the button is used in the navigator window (through overlays), the fonts/colors used should not be described by messenger. this allows the button to blend in as much as possible regardless of where it is used. the importance of this rule cannot be overstated. derived skin files should not contain any rules for colors, fonts, or borders. exceptions to this rule must be approved in order to be allowed into the product. note that in our current designed mozilla skin (aside from global) every single css file is a derived skin file, so this applies to all of you!!! derived skin files should not attempt to change the default look for a widget. for example, there should never be any css rules of the form tagname {...}; in a derived skin file.

Settings - Archive of obsolete content
the debugger has its own settings menu, which you can access from an icon in the toolbar: each setting is a simple on/off switch: auto prettify minified sources with this option enabled, the debugger will automatically detect minified js files and pretty-print them. pause on exceptions when this option is enabled, execution of the script will automatically pause whenever a javascript exception is thrown. ...
...s from an icon in the toolbar: each setting is a simple on/off switch: auto prettify minified sources with this option enabled, the debugger will automatically detect minified js files and pretty-print them. pause on exceptions when this option is enabled, execution of the script will automatically pause whenever a javascript exception is thrown. ignore caught exceptions if this option is set (it is set by default) and "pause on exceptions" is set, then execution will pause on an exception only if that exception is not caught. this is usually the behavior you want. you don't generally want to pause execution when an exception that is thrown is caught, since that generally indicates that your program is handling it properly. show panes o...

Browser Detection and Cross Browser Support - Archive of obsolete content
de these users with alternative unscripted versions of your pages or to at least notify them of the need to use scripting in order to view your content properly. since browsers such as netscape navigator 4 and internet explorer 4 do not support some of the most recent additions to the javascript (ecmascript) standard, it is often necessary to limit the use of advanced javascript features such as exception processing. one approach is to require that users of browsers which do not support the level of javascript used in your content to turn off javascript in order to be able to use your content. you can do this by providing an error message for users of older browsers as well as alternative content contained in noscript tags. <html> <head> <title>noscript</title> </head> <body> <scrip...
...</head> <body> <script language="javascript"> window.onerror = function () { // redirect user to a page describing the limitations // of their browser and requesting that they turn off // javascript in order to view your site. } // netscape navigator 4 will throw an error // on any javascript which attempts to use // try ... catch exception processing. try { // code to implement fancy menu } catch (errors) { // handle exceptions } </script> <noscript> <!-- if javascript is not enabled, then the browser will display the contents of the noscript tag which in this case is a simple menu implemented as an unordered list. --> <ul> ...

LiveConnect - Archive of obsolete content
or remove as needed.) while the bloated liveconnect code in the mozilla source was removed in version 1.9.2 of the platform (see bug 442399), its former api has been restored (see also the specification and this thread) (building on npapi?), and as of java 6 update 12, extensions as well as applets can make use of this restored api. the reimplementation also restores the ability to use try-catch exceptions within javascript, and is free of the increasing number of other bugs introduced by the decline of the original liveconnect (e.g., java.lang.string and arrays not working properly). liveconnect use by applets is enabled via the use of the "mayscript" attribute in applet tags on an html page, following which the applet may refer to classes in the netscape.javascript package to access javascript ...
...ion by javascript code (e.g. by writing code like "new java.lang.string('javascript string')" for classes in the java.* package hierarchy, or using a new "packages" object for classes outside this hierarchy). old liveconnect documents, broken links: java method overloading and liveconnect 3 the technique that liveconnect uses to invoke overloaded java methods from javascript. liveconnect exceptions how do java and javascript catch exceptions generated by the other party? liveconnect testcases determine that applets within different html tags work properly. note: liveconnect blocked under some conditions liveconnect calls from javascript to java api are blocked when the java control panel security slider is set to very high level, or when the slider is at the default high level ...

Index - MDN Web Docs Glossary: Definitions of Web-related terms
hanics an entity header is an http header that can be used in an http request or response, and describes the content of the body of themessage. headers like content-length, content-language, content-encoding are entities headers. 135 event codingscripting, glossary events are assets generated by dom elements, which can be manipulated by a javascript code. 136 exception beginner, codingscripting, glossary an exception is a condition that interrupts normal code execution. in javascript syntax errors are a very common source of exceptions. 137 expando codingscripting, javascript, reference, expando expando properties are properties added to dom nodes with javascript, where those properties are not part of the object's dom specificati...
...ear to instantly as possible). 443 syntax codingscripting, glossary, syntax syntax specifies the required combination and sequence of characters making up correctly structured code. syntax generally includes grammar and the rules that apply to writing it, such as indentation requirements in python. 444 syntax error codingscripting, glossary, javascript an exception caused by the incorrect use of a pre-defined syntax. syntax errors are detected while compiling or parsing source code. 445 synthetic monitoring glossary, rum, reference, synthetic monitoring, web performance synthetic monitoring involves monitoring the performance of a page in a 'laboratory' environment, typically with automation tooling in an environment that is as consiste...

WAI-ARIA basics - Learn web development
idea of support levels by looking at powermapper's wai-aria screen reader compatibility article. in this article, we won't attempt to cover every wai-aria feature, and its exact support details. instead, we will cover the most critical wai-aria features for you to know about; if we don't mention any support details, you can assume that the feature is well-supported. we will clearly mention any exceptions to this. note: some javascript libraries support wai-aria, meaning that when they generate ui features like complex form controls, they add aria attributes to improve the accessibility of those features. if you are looking for a 3rd party javascript solution for rapid ui development, you should definitely consider the accessibility of its ui widgets as an important factor when making your choi...
.... polite: updates should be announced only if the user is idle. assertive: updates should be announced to the user as soon as possible. we'd like you to take a copy of aria-no-live.html and quotes.json, and update your <section> tag as follows: <section aria-live="assertive"> this will cause a screenreader to read out the content as it is updated. note: most browsers will throw a security exception if you try to do an xmlhttprequest call from a file:// url, e.g. if you just load the file by loading it directly into the browser (via double clicking, etc.). to get it to run, you will need to upload it to a web server, for example using github, or a local web server like python's simplehttpserver. there is an additional consideration here — only the bit of text that updates is read out. it...

Web fonts - Learn web development
e finished example live). using an online font service online font services generally store and serve fonts for you, so you don't have to worry about writing the @font-face code, and generally just need to insert a simple line or two of code into your site to make everything work. examples include adobe fonts and cloud.typography. most of these services are subscription-based, with the notable exception of google fonts, a useful free service, especially for rapid testing work and writing demos. most of these services are easy to use, so we won't cover them in great detail. let's have a quick look at google fonts, so you can get the idea. again, use copies of web-font-start.html and web-font-start.css as your starting point. go to google fonts. use the filters on the left-hand side to displa...
... case is optional, but it is useful to declare it because it allows browsers to find a font they can use faster. multiple declarations can be listed, separated by commas — the browser will search through them and use the first one it can find that it understands — it is therefore best to put newer, better formats like woff2 earlier on, and older, not so good formats like ttf later on. the one exception to this is the eot fonts — they are placed first to fix a couple of bugs in older versions of ie whereby it will try to use the first thing it finds, even if it can't actually use the font. font-weight/font-style: these lines specify what weight the font has, and whether it is italic or not. if you are importing multiple weights of the same font, you can specify what their weight/style is and ...

What is a URL? - Learn web development
p, url is one of the key concepts of the web. it is the mechanism used by browsers to retrieve any published resource on the web. url stands for uniform resource locator. a url is nothing more than the address of a given unique resource on the web. in theory, each valid url points to a unique resource. such resources can be an html page, a css document, an image, etc. in practice, there are some exceptions, the most common being a url pointing to a resource that no longer exists or that has moved. as the resource represented by the url and the url itself are handled by the web server, it is up to the owner of the web server to carefully manage that resource and its associated url. active learning there is no active learning available yet. deeper dive basics: anatomy of a url here are some exa...
...isplay media such as images (with the <img> element), videos (with the <video> element), sounds and music (with the <audio> element), etc.; to display other html documents with the <iframe> element. note: when specifying urls to load resources as part of a page (such as when using the <script>, <audio>, <img>, <video>, and the like), you should generally only use http and https urls, with few exceptions (one notable one being data:; see data urls). using ftp, for example, is not secure and is no longer supported by modern browsers. other technologies, such as css or javascript, use urls extensively, and these are really the heart of the web. absolute urls vs relative urls what we saw above is called an absolute url, but there is also something called a relative url. let's examine what that ...

Drawing graphics - Learn web development
browser; the below example shows a simple rotating webgl cube: this article will focus mainly on 2d canvas, as raw webgl code is very complex. we will however show how to use a webgl library to create a 3d scene more easily, and you can find a tutorial covering raw webgl elsewhere — see getting started with webgl. note: basic canvas functionality is supported well across browsers, with the exception of ie 8 and below for 2d canvas, and ie 11 and below for webgl. active learning: getting started with a <canvas> if you want to create a 2d or 3d scene on a web page, you need to start with an html <canvas> element. this element is used to define the area on the page into which the image will be drawn. this is as simple as including the element on the page: <canvas width="320" height="240"></...
...ordinate, it would appear 85 pixels lower than the mouse position. function draw() { if(pressed) { ctx.fillstyle = colorpicker.value; ctx.beginpath(); ctx.arc(curx, cury-85, sizepicker.value, degtorad(0), degtorad(360), false); ctx.fill(); } requestanimationframe(draw); } draw(); note: the <input> range and color types are supported fairly well across browsers, with the exception of internet explorer versions less than 10; also safari doesn't yet support color. if your browser doesn't support these inputs, they will fall back to simple text fields and you'll just have to enter valid color/number values yourself. webgl it's now time to leave 2d behind, and take a quick look at 3d canvas. 3d canvas content is specified using the webgl api, which is a completely separate ...

Starting our Svelte Todo list app - Learn web development
todo --> <form> <h2 class="label-wrapper"> <label for="todo-0" class="label__lg"> what needs to be done? ...
... clip: rect(1px 1px 1px 1px); clip: rect(1px, 1px, 1px, 1px); white-space: nowrap; } [class*="stack"] > * { margin-top: 0; margin-bottom: 0; } .stack-small > * + * { margin-top: 1.25rem; } .stack-large > * + * { margin-top: 2.5rem; } @media screen and (min-width: 550px) { .stack-small > * + * { margin-top: 1.4rem; } .stack-large > * + * { margin-top: 2.8rem; } } .stack-exception { margin-top: 1.2rem; } /* end global styles */ .todoapp { background: #fff; margin: 2rem 0 4rem 0; padding: 1rem; position: relative; box-shadow: 0 2px 4px 0 rgba(0, 0, 0, 0.2), 0 2.5rem 5rem 0 rgba(0, 0, 0, 0.1); } @media screen and (min-width: 550px) { .todoapp { padding: 4rem; } } .todoapp > * { max-width: 50rem; margin-left: auto; margin-right: auto; } .todoapp > f...

Gecko info for Windows accessibility vendors
mozillahiddenwindowclass - ignore these windows, they are used to help manage other windows mozillawindowclass - general filler window, a catch all starting in firefox 2, however, you should begin switching your code to use navrelation_embeds. going forward, this may be the only way to efficiently find the content area, as mozilla will begin to become a windowless application, with an exception for plugins which create their own window. when you see the content window receive focus, first check the role. if it is role_pane or role_document then this should be treated as a document for the default modality of the screen reader. if it is a role_application, role_dialog or role_alert then stay in focus tracking mode -- there is no need to parse the document. in addition, if it is a role_...
..._show, event_hide and event_locationchange are fired for the caret object. event_reorder is fired on an object whenever its children change. event_show and event_hide may also be fired with the reorder event, for the child who's visibility changed. the show and hide events are not fired on every iaccessible when a new subtree of iaccessibles changes visibility -- only the top iaccessible. the exception is progress meters, which are guaranteed to fire event_show and event_hide events when they are displayed or hidden. event_alert is fired when an object of role_alert appears or changes. this should indicate to a screen reader to read the contents of the alert (it may be a container who's descendents should be read). event_selection is fired on children of single selection containers alon...

What to do and what not to do in Bugzilla
reopened only if the original reporter provides more info, or confirms someone else's steps to reproduce. if the bug is long, when enough info is provided a new bug should be filed and the original bug marked as a duplicate of it. resolving bugs as invalid you should resolve a bug as invalid if the issue described in the bug is clearly not a mozilla bug or if the issue is intended behavior. the exceptions are bugs in other software which we have to work around and bugs that involve certain core gecko modules. bugs covered by this exception should not be invalidated by anyone other than the module owner or module peer; for bugs involving modules like layout or content, attach a test case to the bug and then cc one of the owners or peers. reports of problems with specific websites that result from ...
...m like misspelled words or misaligned text enhancement request for enhancement the blocker severity should be used very seldomly, because only a fraction of the hundreds of thousands bugs really block the development of mozilla and these are normally fixed very quickly. as a result, bugs which are unconfirmed for more than a few days do not qualify for the blocker severity. the exceptions to this rule are platform-specific or compiler-specific bugs. basically, anything that prevents builds from building, running, or being used for dogfood (able to use bugzilla, tinderbox, lxr, etc.) is a blocker. bug reports about crashes, hangs, data-loss, or severe security exploits (e.g. remote execution of arbitrary code) get the critical severity. priority/target milestone as stated in th...

CustomizableUI.jsm
customizableui provides a way to listen for various bits of customization happening. this can be useful if other parts of the code need to react to changes in the customization of the user interface. in order to use this facility, you should create a plain js object which defines some of the event handlers defined below. not all event handler methods need to be defined. customizableui will catch exceptions. events are dispatched synchronously on the ui thread, so if you can delay any/some of your processing, that is advisable. the following event handlers are supported: onwidgetadded(awidgetid, aarea, aposition) fired when a widget is added to an area. awidgetid is the widget that was added, aarea the area it was added to, and aposition the position in which it was added. onwidgetmoved(awidg...
... you want to ensure it was added. beginbatchupdate() start a batch update of items. during a batch update, the customization state is not saved to the user's preferences file, in order to reduce (possibly sync) io. calls to begin/endbatchupdate may be nested. callers should ensure that no matter what happens they call endbatchupdate once for each call to beginbatchupdate, even if there are exceptions in the code in the batch update. otherwise, for the duration of the firefox session, customization state is never saved. typically, you would do this using a try...finally block wrapped around your insertion code. endbatchupdate() end a batch update. see the documentation for beginbatchupdate above. state is not saved if we believe it is identical to the last known saved state. state is onl...

FileUtils.jsm
optional file open flags (see constants above) return value returns nsifileoutputstream (the non-safe variant) to write to. openatomicfileoutputstream() opens an atomic file output stream for writing. note: 'safe' and 'atomic' file output streams will never append; they will always overwrite an existing file. starting in gecko 38.0, passing mode_append without mode_truncate will throw an exception. nsifileoutputstream openatomicfileoutputstream( nsifile file, int modeflags ); parameters file the file to write to. modeflags optional file open flags (see constants above) return value returns nsifileoutputstream (the safe variant) to write to. note: openatomicfileoutputstream() is generally better than opensafefileoutputstream() because flushing is not needed in most of the ...
...file output stream. void closeatomicfileoutputstream( nsifileoutputstream stream ); parameters stream the stream to close. opensafefileoutputstream() opens a safe file output stream for writing. note: 'safe' and 'atomic' file output streams will never append; they will always overwrite an existing file. starting in gecko 38.0, passing mode_append without mode_truncate will throw an exception. nsifileoutputstream opensafefileoutputstream( nsifile file, int modeflags ); parameters file the file to write to. modeflags optional file open flags (see constants above) return value returns nsifileoutputstream (the safe variant) to write to. remarks note: starting in gecko 6 the stream is opened with the defer_open nsifileoutputstream behavior flag constant; this means the...

OS.File for the main thread
to copy. at the time of this writing, this function does not copy directories. destpath the full path of the destination. note that this is not a directory but a file. optionsoptional an optional object used to control the behavior of this function. you may pass an object with a subset of the following fields: nooverwrite if destpath already exists, do not overwrite it, but rather launch an exception. promise can be rejected with os.file.error in case of any error, in particular if the file does not exist. performance notes to avoid erasing the destination file, it is much faster to use option nooverwrite than to check manually whether the file exists. this operation is os-optimized under os x (native operation copyfile), linux/android (native operation splice), and windows (nati...
...th is a directory. destpath the full path of the destination. at the time of this writing, the behavior of this function is unspecified if destpath is a directory. optionsoptional an optional object used to control the behavior of this function. you may pass an object with a subset of the following fields: nooverwrite if destpath already exists, do not overwrite it, but rather launch an exception. nocopy if moving the file would require a copy (i.e. if the destination path resides on another drive/device/file system as the source path), fail. promise can be rejected with os.file.error in case of any error, in particular if the file does not exist. performance note: this operation is os-optimized under os x, linux/android, and windows. os.file.read() read the contents o...

PromiseWorker.jsm
ge; } customerror.prototype.tomsg = function() { return { exn: 'customerror', message: this.message, }; }; // a function called by message. function func() { ... // throw a custom error. ...
... the complete demo is found here: github :: promiseworker custom errors demo catching the promise from the worker, it is not possible, as of firefox 40, to cause the promise on the main thread catch. ...

Mozilla DOM Hacking Guide
class corresponding to the data passed in. the implementation is detailed in section 1.6. static void shutdown(): releases the interface pointers. static nsiclassinfo* docreate(nsdomclassinfodata* adata): inline function that returns a nsiclassinfo pointer to a new instance of the nsdomclassinfo class. static nsresult wrapnative(...): xpconnect fu, not our problem. static nsresult throwjsexception(jscontext *cx, nsresult aresult);: help me! static nsresult initdomjsclass(jscontext *cx, jsobject *obj);: help me! static jsclass sdomjsclass;: help me! protected section: const nsdomclassinfodata* mdata;: help me! static nsresult init(): called only once, it is used to initialize the remaining members of the nsdomclassinfodata structure, as mentioned above. once called, init() set...
...of type "location". however a common technique is to do window.location = "http://mozilla.org" instead of the correct window.location.href = "http://mozilla.org". so, we have to override the default behavior of "setting the location property on the window object". the default behavior would be that xpconnect expects a nsidomlocation object. however it would be passed a js string. a bad conversion exception would be thrown. before we start looking at the implementation of the nsixpcscriptable interface, the implementor needs the following information: which dom object is concerned what action does he want to override what should happen for our example, it is the window object. the action is setting a property. what should happen is that setting .location should set .location.href. with that...

A brief guide to Mozilla preferences
can call up to four methods: pref(), user_pref(), sticky_pref() and lockpref(). all preferences files may call pref(), user_pref() and sticky_pref(), while the config file in addition may call lockpref(). preferences files to protect privacy by preventing inadvertent loading of a preferences file in the browser, the first line of the file is made un-parseable and skipped on loading. the only exception to this is user.js . on application launch, several preferences files are loaded. they are: default preference files firefox ships default preferences in several files, all in the application directory: greprefs.js - preferences shared by all applications using the mozilla platform services/common/services-common.js - preferences for some shared services code, this should arguably b...
...et preferences are saved to prefs.js . this also means that preferences initially set by user.js will also be saved to prefs.js. do not edit prefs.js directly. note the application never changes user.js, so on launch user.js overrides conflicting preferences from the previous application session. when prefs.js is written, it only saves user preferences which are different from the default. the exception to this is a preference read using sticky_pref() - these preference will be written whenever the preference has a user value even when it is the same as the default. modifying preferences advanced users can set named preferences via the advanced preferences editor, by typing about:config in the location bar. this ui is not recommended for most users. programmatic changes to preferences can be...

PR_Poll
led. the reason for the failure can be obtained by calling pr_geterror. description this function returns as soon as i/o is ready on one or more of the underlying socket objects. a count of the number of ready descriptors is returned unless a timeout occurs, in which case zero is returned. the in_flags field of the prpolldesc data structure should be set to the i/o events (readable, writable, exception, or some combination) that the caller is interested in. on successful return, the out_flags field of the prpolldesc data structure is set to indicate what kind of i/o is ready on the respective descriptor. pr_poll uses the out_flags fields as scratch variables during the call. if pr_poll returns 0 or -1, the out_flags fields do not contain meaningful values and must not be used. the prpolldesc s...
...t, including one representing a file or a pipe. cross-platform applications should only set the fd field to a pointer to a prfiledesc object representing a socket or a pollable event because on windows the select function can only be used with sockets. in_flags a bitwise or of the following bit flags: pr_poll_read: fd is readable. pr_poll_write: fd is writable. pr_poll_except: fd has an exception condition. out_flags a bitwise or of the following bit flags: pr_poll_read pr_poll_write pr_poll_except pr_poll_err: fd has an error. pr_poll_nval: fd is bad. note that the pr_poll_err and pr_poll_nval flags are used only in out_flags. the pr_poll_err and pr_poll_nval events are always reported by pr_poll. ...

Rhino scopes and contexts
h execution, simply exit the context: context.exit(); these calls will work properly even if there is already a context associated with the current thread. that context will be returned and an internal counter incremented. only when the counter reaches zero will it be disassociated from the thread. remember to put the exit() call in a finally block if you're executing code that could throw an exception. scopes a scope is a set of javascript objects. execution of scripts requires a scope for top-level script variable storage as well as a place to find standard objects like function and object. it's important to understand that a scope is independent of the context that created it. you can create a scope using one context and then evaluate a script using that scope and another context (either ...
...ork properly for other scripts. such bugs are hard to debug and to remove a possibility for them to occur one can seal the shared scope and all its objects. a notion of a sealed object is a javascript extension supported by rhino and it means that properties can not be added/deleted to the object and the existing object properties can not be changed. any attempt to modify sealed object throws an exception. to seal all objects in the standard library passtrue for the sealed argument when calling context.initstandardobjects(scriptableobject, boolean): scriptableobject sealedsharedscope = cx.initstandardobjects(null, true); this seals only all standard library objects, it does not seal the shared scope itself thus after callinginitstandardobjects, sealedsharedscope can be farther populated with ap...

Rhino serialization
ino serialization in an environment where you always define, say, a constructor foo, you should add the following code before calling writeobject: out.addexcludedname("foo"); out.addexcludedname("foo.prototype"); this code will prevent foo and foo.prototype from being serialized and will cause references to foo or foo.prototype to be resolved to the objects in the new scope upon deserialization. exceptions will be thrown if foo or foo.prototype cannot be found the scopes used in either scriptableoutputstream or scriptableinputstream. rhino serialization in compilation mode serialization works well with objects and with functions and scripts in interpretive mode. however, you can run into problems with serialization of compiled functions and scripts: $ cat test.jsfunction f() { return 3; } serializ...
... with objects and with functions and scripts in interpretive mode. however, you can run into problems with serialization of compiled functions and scripts: $ cat test.jsfunction f() { return 3; } serialize(f, "f.ser"); g = deserialize("f.ser"); print(g()); $ java org.mozilla.javascript.tools.shell.main -opt -1test.js 3 $ java org.mozilla.javascript.tools.shell.main test.js js: uncaught javascript exception: java.lang.classnotfoundexception:c1 the problem is that java serialization has no built-in way to serialize java classes themselves. (it might be possible to save the java bytecodes in an array and then load the class upon deserialization, but at best that would eat up a lot of memory for just this feature.) one way around this is to compile the functions using the jsc tool: $ cat f.js function...

Creating JavaScript jstest reftests
test. additionally, it loads every shell.js and broswer.js file in the subdirectories on the path from js/src/tests to the location of your test. if you have functionality several tests share in a given folder, you can add the functionality to the shell.js or broswer.js file in the directory. asserteq asserteq(v1, v2[, message]) checks that v1 and v2 are the same value. if they're not, throw an exception (which will cause the test to fail). reportcompare reportcompare(expected, actual, description) is somewhat like asserteq(actual, expected, description) except that the first two arguments are swapped, failures are reported via stdout rather than by throwing exceptions, and the matching is fuzzy in an unspecified way. for example, reportcompare sometimes considers numbers to be the same if they...
...e> --- that tells the post-processing scripts jsdriver.pl or post-process-logs.pl that the test passes if the shell or browser terminates with that exit code. multiple calls to expectexitcode will tell the post-processing scripts that the test actually passed if any of the exit codes are found when the test terminates. this approach has limited use, however. in the javascript shell, an uncaught exception or out of memory error will terminate the shell with an exit code of 3. however, an uncaught error or exception will not cause the browser to terminate with a non-zero exit code. to make the situation even more complex, newer c++ compilers will abort the browser with a typical exit code of 5 by throwing a c++ exception when an out of memory error occurs. simply testing the exit code does not allo...

Invariants
in gc" and no threads are in requests; or no thread is doing gc, in which case any number of threads may be in requests; or the gc lock is held. a thread that holds the gc lock never does anything that blocks. a thread that is in a request never does anything that blocks. there are the usual invariants regarding locks: we do not reenter them (it would be nice to check this as there might be an exception or two); we do not wait on a condition variable unless the corresponding lock is held. there are the usual invariants regarding various fields: they are protected by certain locks or more complex locking schemes. in particular, native objects' fields are protected by property locking (below); and several things are protected by the request model, such that there may be either one writer (in gc) ...
...e locking scheme is described under jsobjectops.dropproperty. (note that the locking scheme applies to all objects and talks about properties being locked. as implemented for native objects, the locking is not really that fine-grained, but that is a transparent optimization as long as we follow the rules.) a thread holding a property lock never leaves or suspends the current request. with a few exceptions (known to brendan and probably jst and mrbkap), we never call a jsapi callback with a property locked. (that would risk deadlock too.) name instructions the first operand to a jsop_setname instruction is always produced by a preceding jsop_bindname instruction. (taken together, ecma 262-3 §11.13.1 and ecma 262-3 §10.1.4 specify that in an assignment such as x = f(), the name lookup for x oc...

JSNative
added in spidermonkey 24 as well as through "jsapi.h".) this structure encapsulates access to the callee function, this, the function call's arguments, and the eventual return value. on success, the callback must set js::callargs::rval() or call js_set_rval (at least once) and return true. otherwise it should either report an error (using e.g. js_reporterror or js_reportoutofmemory) or raise an exception (using js_setpendingexception), and the callback must return false. (returning false without reporting an error or raising an exception terminates the script with an uncatchable error. this has limited use cases; it's used to implement firefox's "slow script" dialog, for example.) when a jsnative is called, no jsstackframe is generated. this causes the function not to appear on the stack in jav...
...to appear on the stack in javascript debuggers. it also means that applications that implement jscheckaccessop or jscheckaccessidop in terms of apis such as js_frameiterator and js_stackframeprincipals, must take extra care, as the native function's principals will be missing from the stack. see also mxr id search for jsnative js::callargs js_reporterror js_reportoutofmemory js_setpendingexception ...

JS_DefineProperty
trs). if obj already has an own property with the given name or id, the existing property is replaced. these functions can currently replace jsprop_permanent properties, but such usage is deprecated. the javascript engine will call the getter or setter callback each time the property is read or written, whether from javascript code or via jsapi functions like js_getproperty and js_setproperty. (exception: if attrs contains the jsprop_readonly flag, the setter will never be called, as property assignment will fail before it gets that far. also note that certain jsapi functions, including js_lookupproperty, js_hasproperty, and property_attributes, can detect or examine a property without calling its getter.) if getter (or setter) is null, the new property will use the jsclass.getproperty (or jsclas...
... from obj's class. if attrs contains the jsprop_getter (or jsprop_setter) flag, then getter (or setter) must point to a javascript function, not a c/c++ function. that is, it must be a jsobject * that points to a javascript function, cast to type jspropertyop. for more about javascript getters and setters, see defining getters and setters. on success, js_defineproperty returns true. on error or exception, it returns false. see also mxr id search for js_defineproperty mxr id search for js_defineucproperty mxr id search for js_definepropertybyid js_defineelement bug 461163 bug 1113369 -- added desc and result parameters ...

JS_ReportError
syntax void js_reporterror(jscontext *cx, const char *format, ...); bool js_reportwarning(jscontext *cx, const char *format, ...); name type description cx jscontext * pointer to a js context from which to derive runtime information. requires request. in a js_threadsafe build, the caller must be in a request on this jscontext. format const char * format string to convert into an error message using js_vsmprintf. ...
...porterror is the simplest jsapi function for reporting errors. first it builds an error message from the given sprintf-style format string and any additional arguments passed after it. the resulting error message is passed to the context's jserrorreporter callback, if any. if the caller is in a jsapi callback, js_reporterror also creates a new javascript error object and sets it to be the pending exception on cx. the callback must then return js_false to cause the exception to be propagated to the calling script. an example is shown in the jsapi phrasebook. for internationalization, use js_reporterrornumber instead. to report an out-of-memory error, use js_reportoutofmemory. see also mxr id search for js_reporterror mxr id search for js_reportwarning ...

JS_ReportErrorNumber
nter that was passed to the reporterrornumber api. errornumber const unsigned the errornumber that was passed to the reporterrornumber api. description these functions create a jserrorreport, populate it with an error message obtained from the given jserrorcallback, and either report it to the current error reporter callback or create an error object and set it as the pending exception. first errorcallback(userref, errornumber) is called. if errorcallback returns null, (??? what happens?). otherwise, if the jserrorformatstring returned by the jserrorcallback has .exntype == jsexn_none, then the error reporter, if any, is called, and no error object is created. (??? the source code seems to say we ignore the .exntype, actually, but surely i'm just missing something.) otherwise, ...
...llback has .exntype == jsexn_none, then the error reporter, if any, is called, and no error object is created. (??? the source code seems to say we ignore the .exntype, actually, but surely i'm just missing something.) otherwise, if any javascript code is running in cx (for example, if the caller is a jsnative that was called from a script), then an error object is created and becomes the pending exception. the error reporter is not called yet, because the script still has an opportunity to catch and handle the exception. otherwise, no javascript code is running in cx. if the jsoption_dont_report_uncaught option is set, (??? what happens?). otherwise, (??? what happens?). see also mxr id search for js_reporterrornumber mxr id search for js_reporterrornumberuc mxr id search for js_reporterrorfla...

JS_ValueToNumber
, conversion succeeds, and the result is nan, 0, 0, or 1 respectively. if v is a string, conversion proceeds as specified in ecma 262-3 §9.3.1. js_valuetonumber always succeeds in this case, returning js_true. if the string is not a numeric string, *dp is set to nan. otherwise v is an object. js_valuetonumber carries out the following steps to convert it to a number. if at any step an error or exception occurs, or conversion succeeds, the rest of the steps are skipped. (this behavior is implemented by v's jsobjectops.defaultvalue hook, so host objects can override it all.) first, the object's jsclass.convert callback is called. for objects of standard classes, this is js_convertstub, which simply calls v.valueof() if present. if the convert callback produces a primitive value, the value is...
...rted to a number as described above and conversion succeeds. otherwise, the resulting object's tostring method, if any, is called. if that produces a primitive value, the value is converted to a number as described above and conversion succeeds. otherwise conversion fails with a typeerror. on success, js_valuetonumber stores the converted value in *dp and returns js_true. on error or exception, it returns js_false, and the value left in *dp is undefined. see also js_convertarguments js_convertvalue js_gettypename js_typeofvalue js_valuetoint32 js_valuetoecmaint32 bug 884410 ...

JS_ValueToString
v is a number, conversion succeeds, and the result is a string representation of that number as specified in ecma 262-3 §9.8.1. this might be "nan", "infinity", or "-infinity". otherwise the result is a decimal representation of the number, possibly using exponential notation. otherwise v is an object. js_valuetostring uses the steps below to convert it to a string. if at any point an error or exception occurs, or conversion succeeds, the rest of the steps are skipped. (this behavior is implemented by v's jsobjectops.defaultvalue method, so host objects can override it all.) if v.tostring() is a function, it is called. if that method returns a primitive value, the value is converted to a string as described above and conversion succeeds. otherwise, the resulting object's jsclass.convert...
...ulting object's jsclass.convert callback is called. for standard classes, this is js_convertstub, which simply calls v.valueof() if present. if the convert callback produces a primitive value, the value is converted to a string as described above and conversion succeeds. otherwise conversion fails with a typeerror. on success, js_valuetostring returns a pointer to a string. on error or exception, it returns null. this happens, for example, if v is an object and v.tostring() throws an exception. the resulting jsstring is subject to garbage collection. protect it using a local root, an object property, or the js_addroot function. see also bug 933834 js::tostring ...

Setting up the Gecko SDK
tory. if your component will use other parts of the sdk (e.g., necko), you will have to add these include directories to this field as well. assuming you are using the example location for your project, these paths are the following: c:\gecko-sdk\embedstring\include c:\gecko-sdk\xpcom\include c:\gecko-sdk\nspr\include c:\gecko-sdk\string\include under the c++ language category, disable exception handling. as described in the section exceptions in xpcom, exception handling isn't supported across interface boundaries, so setting this option may catch problems during development. the weblock component needs to link against the appropriate libraries to uses xpcom glue. to add these libraries, select the link tab, then choose the input category. in this panel, instead of linking to the inclu...
...ing, see the make manual. sample makefile for the gecko sdk module = mozshim # change this to point at your gecko sdk directory. gecko_sdk_path ?= $(home)/tmp/xr xpidl ?= $(gecko_sdk_path)/bin/xpidl cxx ?= c++ xpidlsrcs = \ interfacea.idl \ interfaceb.idl \ $(null) cppsrcs = \ sourcea.cpp \ sourceb.cpp \ $(null) cppflags += -fno-rtti \ -fno-exceptions \ -fshort-wchar \ -fpic \ $(null) # gcc only define which allows us to not have to #include mozilla-config # in every .cpp file. if your not using gcc remove this line and add # #include "mozilla-config.h" to each of your .cpp files. gecko_config_include = -include mozilla-config.h gecko_defines = -dmozilla_strict_api gecko_includes = -i$(gecko_sdk_path) ...

Components object
he nsixpccomponents interface which is reflected into javascript as a top level object using xpconnect. some properties of components require advanced privileges and may not work in web pages. ...
...eflected into javascript as a top level object using xpconnect. some properties of components require advanced privileges and may not work in web pages. ...

Using components
it is common to start addon scripts like: var cc = components.classes; var ci = components.interfaces; there is also another way to start, which is exactly equivalent to the above. var {cc: classes, ci: interfaces} = components; there are many more than just classes and interfaces. var { cu: utils, ci: interfaces, cc: classes, cr: results, cs: stack, cm: manager, ce: exception, } = components; here is a full breakdown of what is contained in components. any of the below can be accessed by components.blah (ie: components.issuccesscode) utils=[object nsxpccomponents_utils] interfaces=[object nsxpccomponents_interfaces] classes=[object nsxpccomponents_classes] results=[object nsxpccomponents_results] issuccesscode=function issuccesscode() { [native code] } constructor=[o...
...] issuccesscode=function issuccesscode() { [native code] } constructor=[object nsxpccomponents_constructor] queryinterface=function queryinterface() { [native code] } interfacesbyid=[object nsxpccomponents_interfacesbyid] classesbyid=[object nsxpccomponents_classesbyid] stack=js frame :: scratchpad/4 :: cdump :: line 8 manager=[xpconnect wrapped nsicomponentmanager] id=[object nsxpccomponents_id] exception=[object nsxpccomponents_exception] reporterror=function reporterror() { [native code] } cancreatewrapper=function cancreatewrapper() { [native code] } cancallmethod=function cancallmethod() { [native code] } cangetproperty=function cangetproperty() { [native code] } cansetproperty=function cansetproperty() { [native code] } ...

Language bindings
pt as a top level object using xpconnect.components.classescomponents.classes is a read-only object whose properties are classes indexed by contractid.components.classesbyidcomponents.classesbyid is a read-only object whose properties are classes indexed by cid.components.constructorcreates a javascript function which can be used to create or construct new instances of xpcom components.components.exceptioncomponents.exception is a javascript constructor to create nsixpcexception objects. these exception objects may be thrown when implementing xpcom interfaces in javascript, and they can provide better diagnostics in the error console if not caught than simply throwing an nsresult's value will.components.idcomponents.id is a constructor that creates native objects that conform to the nsijsid interfa...
...e, and if any native properties have been redefined, this has no effect.components.utils.makeobjectpropsnormalensures that the specified object's methods are all in the object's scope, and aren't cross-component wrappers.components.utils.reporterrorcomponents.utils.reporterror reports a javascript error object to the error console, and returns. it is meant for use by extension developers who have exception handler blocks which want to "eat" an exception, but still want to report it to the console.components.utils.sandboxcomponents.utils.sandbox is used to create a sandbox object for use with evalinsandbox().components.utils.scheduleprecisegcthis method lets scripts schedule a garbage collection cycle. the garbage collection cycle will occur sometime in the future, when no javascript code is executi...

nsIAccessibleHyperText
this hypertext object. read only. note: renamed from links in gecko 1.9 methods getlink() retrieves the nsiaccessiblehyperlink object at the given link index. nsiaccessiblehyperlink getlink( in long linkindex ); parameters linkindex 0-based index of the link that is to be retrieved. this can be retrieved via getlinkindex(). return value an nsiaccessiblehyperlink object. exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree. ns_error_invalid_arg the link index is invalid. getlinkindex() the link index at the given offset (character index). long getlinkindex( in long charindex ); parameters charindex the 0-based character index. return value the index of the link if it's presented on the given character ...
...ailure indicates that the accessible is unattached from the accessible tree. ns_error_invalid_arg the link index is invalid. getlinkindex() the link index at the given offset (character index). long getlinkindex( in long charindex ); parameters charindex the 0-based character index. return value the index of the link if it's presented on the given character index, otherwise -1. exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree. getselectedlinkindex() obsolete since gecko 1.9 (firefox 3) long getselectedlinkindex(); parameters none. return value missing description exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree. see also nsi...

nsIAccessibleImage
. this method is the same as nsiaccessible.getbounds() excepting coordinate origin parameter. void getimageposition( in unsigned long coordtype, out long x, out long y ); parameters coordtype specifies coordinates origin (for available constants refer to nsiaccessiblecoordinatetype). x the x coordinate of the image accessible position. y the y coordinate of the image accessible position. ...
...age accessible position. exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree. getimagesize() returns the size of the image accessible. this method is the same as nsiaccessible.getbounds(). void getimagesize( out long width, out long height ); parameters width the width of the image accessible. height the height of the image accessible. exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree. ...

nsIAccessibleSelectable
ly. constants constant value description eselection_add 0 eselection_remove 1 eselection_getstate 2 methods addchildtoselection() adds the specified accessible child of the object to the object's selection. if the specified object is already selected, then it does nothing. void addchildtoselection( in long index ); parameters index the zero-based accessible child index. exceptions thrown ns_error_failure if the specified object is not selectable. clearselection() clears the selection in the object so that no children in the object are selected. void clearselection(); parameters none. getselectedchildren() returns an nsiarray of the selected nsiaccessible children. nsiarray getselectedchildren(); parameters none. return value an nsiarray. ischildselected() determines i...
...tion( in long index ); parameters index zero-based selected accessible child index. return value the selected accessible child. removechildfromselection() removes the specified child of the object from the object's selection. if the specified object was not selected, then it does nothing. void removechildfromselection( in long index ); parameters index zero-based accessible child index. exceptions thrown ns_error_failure if the specified object is not selectable. selectallselection() select all children. boolean selectallselection(); parameters none. return value if the object does not accept multiple selection, return false. otherwise, returns true. ...

nsIAnnotationService
n the future. aexpiration one of the expire_* constant value defined above. amimetype mime type of the data to be retrieved. default to "0" if value was not binary data. atype one of type_* constansts defined above. getpageannotationtype() this method retrieves the type of an existing annotation. use getannotationinfo() method, if you need this along with the mime-type etc. it throwns an exception if the annotation is not set. pruint16 getpageannotationtype( in nsiuri auri, in autf8string aname ); parameters auri the uri on which the annotation is set. aname the annotation name. return value returns one of the type_* constants defined above. getitemannotationtype() this method retrieves the type of an existing annotation. use getannotationinfo() method, if you need this a...
...tpageannotationtype( in nsiuri auri, in autf8string aname ); parameters auri the uri on which the annotation is set. aname the annotation name. return value returns one of the type_* constants defined above. getitemannotationtype() this method retrieves the type of an existing annotation. use getannotationinfo() method, if you need this along with the mime-type etc. it throwns an exception if the annotation is not set. pruint16 getpageannotationtype( in long long aitemid, in autf8string aname ); parameters auri the item on which the annotation is set. aname the annotation name. return value returns one of the type_* constants defined above. getpageswithannotation() this method returns a list of all uris having a given annotation. void getpageswithannotation( in...

nsIAuthModule
are in use. void unwrap( [const] in voidptr aintoken, in unsigned long aintokenlength, out voidptr aouttoken, out unsigned long aouttokenlength ); parameters aintoken a buffer containing the data received from the server. aintokenlength the length of the input token. aouttoken a buffer containing the plaintext data from the server. aouttokenlength the length of the output token buffer. exceptions thrown ns_error_not_implemented if the underlying authentication mechanism does not support security layers. wrap() once a security context has been established through calls to getnexttoken() it may be used to protect data exchanged between client and server. calls to this method are used to protect items of data to be sent to the server. void wrap( [const] in voidptr aintoken, in unsigne...
...ned long aouttokenlength ); parameters aintoken a buffer containing the data to be sent to the server. aintokenlength the length of the input token. confidential if set to true, it will encrypt the data, otherwise data will just be integrity protected (checksummed). aouttoken a buffer containing the resulting data to be sent to the server. aouttokenlength the length of the output token buffer. exceptions thrown ns_error_not_implemented if the underlying authentication mechanism does not support security layers. ...

nsIAuthPrompt2
from the user. a single prompt will be shown; then the callbacks for all the coalesced prompts will be notified with the resulting authentication information. serialize prompts that are all in the same "context" (this might mean application-wide, for a given window, or something else depending on the user interface) so that the user is not deluged with prompts. note: this method may throw any exception when the prompt fails to queue, for example because of out-of-memory error. it must not throw when the prompt could already be potentially shown to the user. in that case information about the failure has to come through the callback. this way we prevent multiple dialogs shown to the user because consumer may fall back to synchronous prompt on synchronous failure of this method. nsicancelable as...
...k acontext level one of the level constants. authinfo authentication information object. the implementation should fill in this object with the information entered by the user before returning. return value promptauth() requests a username and a password. implementations will commonly show a dialog with a username and password field, depending on flags also a domain field. note: exceptions thrown from this function will be treated like a return value of false. boolean promptauth( in nsichannel achannel, in pruint32 level, in nsiauthinformation authinfo ); parameters achannel the channel that requires authentication. level one of the level constants. authinfo authentication information object. the implementation should fill in this object with the information enter...

nsIBidiKeyboard
nformation. currently, this is only implemented on windows. methods islangrtl() determines if the current keyboard language is right-to-left. (supported on: win32, mac, gtk2) note: prior to gecko 1.9 this method used a parameter 'out prbool aisrtl' to return the value. boolean islangrtl(); parameters none. return value true if the current keyboard is right-to-left, false if it is not. ...
... remarks implementation windows this implementation uses win32 api to get the language of the keyboard layout, and the direction of those languages. linux this implementation depends on the gecko and gtk+ version. ...

nsIBinaryInputStream
ers none. return value a boolean value read from the stream. readbytearray() reads an opaque byte array from the stream, storing the results as an array of pruint8s. void readbytearray( in pruint32 alength, [array, size_is(alength), retval] out pruint8 abytes ); parameters alength the number of bytes that must be read. abytes an array containing the bytes read from the stream. ...
... readcstring() reads an 8-bit pascal style string from the stream. 32-bit length field, followed by length 8-bit chars. acstring readcstring(); parameters none. return value the string read from the stream. readdouble() reads from the stream. ...

nsIBrowserSearchService
whether the user should be asked for confirmation before this engine is added to the list. if this value is false, the engine will be added to the list upon successful load, but it will not be selected as the current engine. callback a nsisearchinstallcallback that will be notified when the addition is complete, or if the addition fails. it will not be called if addengine throws an exception. exceptions thrown ns_error_failure if the type is invalid, or if the description file cannot be successfully loaded. addenginewithdetails() adds a new search engine, without asking the user for confirmation and without starting to use it right away. void addenginewithdetails( in astring name, in astring iconurl, in astring alias, in astring description, in astring meth...
...lled once initialization is complete, or immediately, if the service has already been initialized. in javascript, this observer can be a regular function. moveengine() moves a visible search engine. void moveengine( in nsisearchengine engine, in long newindex ); parameters engine the engine to move. newindex the engine's new index in the set of visible engines. exceptions thrown ns_error_failure if newindex is out of bounds, or if engine is hidden. removeengine() removes the search engine. if the search engine is installed in a global location, this will just hide the engine. if the engine is in the user's profile directory, it will be removed from disk. void removeengine( in nsisearchengine engine ); parameters engine the engine...

nsICacheService
this is used by the offline cache. the offline cache lets clients accumulate entries in a temporary client and merge them in as a group using nsiofflinecachesession.mergetemporaryclient(). acstring createtemporaryclientid( in nscachestoragepolicy storagepolicy ); parameters storagepolicy the cache storage policy. return value returns a newly created unique, temporary cache client id. exceptions thrown ns_error_not_implemented this method is deprecated. evictentries() this method evicts all entries in all devices implied by the storage policy. note: this function may evict some items but will throw if it fails to evict everything. void evictentries( in nscachestoragepolicy storagepolicy ); parameters storagepolicy the cache storage policy. init() obso...
...storage policy. note: this function may evict some items but will throw if it fails to evict everything. void evictentries( in nscachestoragepolicy storagepolicy ); parameters storagepolicy the cache storage policy. init() obsolete since gecko 1.8 (firefox 1.5 / thunderbird 1.5 / seamonkey 1.0) initialize the cache service. void init(); parameters none. exceptions thrown missing exception missing description shutdown() obsolete since gecko 1.8 (firefox 1.5 / thunderbird 1.5 / seamonkey 1.0) shutdown() the cache service. void shutdown(); parameters none. visitentries() this method visits entries stored in the cache. used to implement the about:cache uri. void visitentries( in nsicachevisitor visitor ); parameters...

nsICategoryManager
entry being modified. ("http") avalue the value for the category entry. ("moz.httprulez.1") apersist no longer supported. category entries never persist across application sessions. you must pass false for this parameter. areplace a flag indicating whether or not to overwrite the value of an existing category entry. return value the previous value for the given category entry (if any). exceptions thrown ns_error_invalid_arg this error is returned if areplace is false and the category entry already has a value, or if apersist is true. deletecategory() delete a category and all entries. note: if the category does not exist, then this method does nothing. void deletecategory( in string acategory ); parameters acategory the name of the category being deleted. deletecategor...
...tscstring. getcategoryentry() get the value for the given category's entry. string getcategoryentry( in string acategory, in string aentry ); parameters acategory the category being queried. ("protocol") aentry the entry being queried. ("http") return value the value of the given category's entry. this pointer must be released using nsimemory.free() when it is no longer needed. exceptions thrown ns_error_not_available indicates that either the category or entry is undefined. examples print out a list of all categories this snippet shows how to print out a list of all categories in c++. nsresult printallcategories() { nsresult rv; nscomptr<nsiservicemanager> svcmgr; rv = ns_getservicemanager(getter_addrefs(svcmgr)); if (ns_failed(rv)) return rv; nscomptr<n...

nsIChannel
tself alive until it has called onstoprequest on alistener or called onchannelredirect. implementations are allowed to synchronously add themselves to the associated load group (if any). void asyncopen( in nsistreamlistener alistener, in nsisupports acontext ); parameters alistener the nsistreamlistener implementation. acontext an opaque parameter forwarded to alistener's methods. exceptions thrown ns_error_already_opened if the channel is reopened ns_error_port_access_not_allowed if the specified port is in the nsioservice forbidden port list. open() synchronously open the channel. note: extensions should not call this method, because it tends to fail when a request is redirected, rather than redirecting transparentlynote: nsichannel implementations are not required to im...
...e: nsichannel implementations are not required to implement this method. moreover, since this method may block the calling thread, it should not be called on a thread that processes ui events. like any other nsichannel method it must not be called on any thread other than the xpcom main thread. nsiinputstream open(); parameters none. return value blocking input stream to the channel's data. exceptions thrown ns_error_in_progress if the channel is reopened. see also nsichanneleventsink for onchannelredirect ...

nsICommandLine
flag, and flags of the form --flag=param are normalized to the form -flag param. astring getargument( in long aindex ); parameters aindex the argument to retrieve. this index is 0-based, and does not include the application name. return value the value of the specified argument. this is the full text of that argument, so if the argument is a flag, the returned value is "-flag [<flagvalue>]". exceptions thrown ns_error_invalid_arg the specified index is out of bounds. handleflag() finds the specified flag, removing it from the array of flags. reports whether or not the specified flag was found. this is useful for boolean flags; that is, flags that don't accept a parameter. you can determine if the flag was provided and remove it from the list of flags waiting to be processed in one operation.
...nes findflag() and removearguments() into one operation. astring handleflagwithparam( in astring aflag, in boolean acasesensitive ); parameters aflag the flag name to find and remove. acasesensitive whether to do case-sensitive flag search. return value the value of the specified flag, an empty string if the flag's value is the empty string, or null if the specified parameter wasn't found. exceptions thrown ns_error_invalid_arg the specified flag has no value. removearguments() removes a range of arguments from the command line; this is typically done once those arguments have been handled. void removearguments( in long astart, in long aend ); parameters astart the index to the first argument to remove from the command line; this is 0-based, and the name of the application is not inc...

nsIDOMHTMLTimeRanges
epresented by the nsidomhtmltimeranges object. read only. methods end() returns the time offset to the end of the specified time range. float end( in unsigned long index ); parameters index the index to the time range whose end time is to be returned. return value the time at which the specified range ends, in seconds measured from the beginning of the timeline represented by the object. exceptions thrown index_size_err the specified index is not valid. start() returns the time offset to the start of the specified time range. float start( in unsigned long index ); parameters index the index to the time range whose start time is to be returned. return value the time at which the specified range starts, in seconds measured from the beginning of the timeline represented by the object. ...
...s thrown index_size_err the specified index is not valid. start() returns the time offset to the start of the specified time range. float start( in unsigned long index ); parameters index the index to the time range whose start time is to be returned. return value the time at which the specified range starts, in seconds measured from the beginning of the timeline represented by the object. exceptions thrown index_size_err the specified index is not valid. ...

nsIDOMNSHTMLDocument
doshowui this is not implemented in gecko. value some commands require an argument. you can pass null for those commands that do not need an argument. return value true if the command was recognized, false otherwise. execcommandshowhelp() obsolete since gecko 14.0 (firefox 14.0 / thunderbird 14.0 / seamonkey 2.11) this method never did anything but throw an exception, and was removed entirely in gecko 14.0 (firefox 14.0 / thunderbird 14.0 / seamonkey 2.11). boolean execcommandshowhelp( in domstring commandid ); parameters commandid the name of the command. return value this method is not supported and always throws an exception. getselection() domstring getselection(); parameters none. return value the text of the current selection, the same as ...
...mandsupported() boolean querycommandsupported( in domstring commandid ); parameters commandid the name of the command to query. return value returns true if the command is supported on the current range, false otherwise. querycommandtext() obsolete since gecko 14.0 (firefox 14.0 / thunderbird 14.0 / seamonkey 2.11) this method never did anything but throw an exception, and was removed entirely in gecko 14.0 (firefox 14.0 / thunderbird 14.0 / seamonkey 2.11). domstring querycommandtext( in domstring commandid ); parameters commandid the name of the command to query. return value this method is not supported and always throws an exception. querycommandvalue() domstring querycommandvalue( in domstring commandid ); parameters commandid the...

nsIDOMWindowUtils
void startpccountprofiling(); void stoppccountprofiling(); void suppresseventhandling(in boolean asuppress); void suspendtimeouts(); nsidomfile wrapdomfile(nsifile afile); attributes attribute type description currentinnerwindowid unsigned long long the id of the window's current inner window. read only. exceptions thrown ns_error_not_available there is no current inner window displaydpi float the dpi of the display. read only. doccharsetisforced boolean whether the charset of the window's current document has been forced by the user. cannot be accessed from unprivileged context (not content-accessible) read only. elementsrestyled read only ...
...tdefault() the event before dispatch. aadditionalflags optional 0 or key_flag_prevent_default and/or one of key_flag_location_*. if key_flag_prevent_default is specified, the dispatching key event's default is prevented. if key_flag_location_* isn't set, an appropriate location is automatically computed from akeycode. if two or more key_flag_location_* is specified, this method will throw an exception. return value false if the event had preventdefault() called on it, true otherwise. in other words, true if and only if the default action was taken. sendmouseevent() synthesize a mouse event. the event types supported are: mousedown, mouseup, mousemove, mouseover, mouseout, contextmenu. events are sent in coordinates offset by ax and ay from the window. note: that additional events may be...

nsIDroppedLinkHandler
n prbool aallowsamedocument ); parameters aevent a dragenter or dragover event. aallowsamedocument if false, drops are only allowed if the document of the source of the drag is different from the destination. this check includes any parent, sibling and child frames in the same content tree. if true, the source is not checked. return value true if the link being dragged can be dropped. exceptions thrown missing exception missing description droplink() given a drop event, determines the link being dragged. if a uri is returned the caller can, for instance, load it. if null is returned, there is no valid link to be dropped. astring droplink( in nsidomdragevent aevent, out astring aname, [optional] in boolean adisallowinherit ); parameters aevent a drop event. aname th...
...s returned the caller can, for instance, load it. if null is returned, there is no valid link to be dropped. astring droplink( in nsidomdragevent aevent, out astring aname, [optional] in boolean adisallowinherit ); parameters aevent a drop event. aname the link title if it exists, or an empty string otherwise. return value a uri, or null if there is no valid link to be dropped. exceptions thrown ns_error_dom_security_err error will be thrown and the event canceled if the receiving target should not load the uri for security reasons. this will occur if the source of the drag initiated a link for dragging that it itself cannot access. this prevents a source document from tricking the user into a dragging a chrome url for example. droplinks() given a drop event, determines th...

nsIMsgFilter
defined in comm-central/ mailnews/ base/ search/ public/ nsimsgfilter.idl attributes type attribute nsmsgruleactiontype type; priority // target priority.. throws an exception if the action is not priority attribute nsmsgpriorityvalue priority; targetfolderuri // target folder.. throws an exception if the action is not move to folder attribute acstring targetfolderuri; label // target label. ...
...entral/ mailnews/ base/ search/ public/ nsimsgfilter.idl attributes type attribute nsmsgruleactiontype type; priority // target priority.. throws an exception if the action is not priority attribute nsmsgpriorityvalue priority; targetfolderuri // target folder.. throws an exception if the action is not move to folder attribute acstring targetfolderuri; label // target label. ...

nsINavBookmarksService
the folder is marked as read-only, otherwise returns false. getfoldertitle() obsolete since gecko 1.9 (firefox 3) note: getitemtitle() provides an alternative for this method. get the title for a bookmark folder. astring getfoldertitle( in print64 folder ); parameters folder the folder whose title should be retrieved. return value the title of the folder. exceptions thrown invalid argument exception if it can not find a folder with the given id. getfolderuri() obsolete since gecko 1.9 (firefox 3) note: getbookmarkuri() provides an alternative for this method. get the url for a bookmark folder. nsiuri getfolderuri( in print64 folder ); parameters folder the folder whose uri should be retrieved. return value the u...
...erwise the indices will become corrupted. warning: this is api is intended for scenarios such as folder sorting, where the caller manages the indices of all items in the folder. you must always ensure each index is unique after a reordering. void setitemindex( in long long aitemid, in long anewindex ); parameters aitemid the id of the item to modify. anewindex the new index. exceptions thrown if anewindex is out of bounds. setitemlastmodified() this method sets the last modified time for an item. note: this is the only method that will send an itemchanged notification for the property. lastmodified will still be updated in any other method that changes an item property, but we will send the corresponding itemchanged notification instead. void setitemlastmodified( ...

nsIProtocolProxyService
to config (pac) may perform a synchronous dns query, which may not return immediately. so, calling resolve without this flag may result in locking up the calling thread for a lengthy period of time. by passing this flag to resolve, one can failover to asyncresolve to avoid locking up the calling thread if a pac query is required. when this flag is passed to resolve, resolve may throw the exception ns_base_stream_would_block to indicate that it failed due to this flag being present. methods resolve() deprecated since gecko 18 this method has been removed in firefox 18. use resolveasync instead previous doc this method returns a nsiproxyinfo instance that identifies a proxy to be used for loading the given uri. otherwise, this method returns null indicating that a direct connectio...
...i auri, in nsresult areason ); parameters aproxyinfo the proxy that was unavailable. auri the uri that was originally passed to resolve/asyncresolve. areason the error code corresponding to the proxy failure. this value may be used to tune the delay before this proxy is used again. the proxy that was unavailable. return value an nsiproxyinfo object or null for a direct connection. exceptions thrown ns_error_not_available if there is no alternate proxy available. registerfilter() this method may be used to register a proxy filter instance. each proxy filter is registered with an associated position that determines the order in which the filters are applied (starting from position 0). when resolve/asyncresolve is called, it generates a list of proxies for the given uri, and the...

nsIRequestObserver
start and end of a request. inherits from: nsisupports last changed in gecko 1.0 method overview void onstartrequest(in nsirequest arequest, in nsisupports acontext); void onstoprequest(in nsirequest arequest, in nsisupports acontext, in nsresult astatuscode); methods onstartrequest() called to signify the beginning of an asynchronous request. note: an exception thrown from onstartrequest has the side-effect of causing the request to be canceled. void onstartrequest( in nsirequest arequest, in nsisupports acontext ); parameters arequest request being observed. acontext user defined context. onstoprequest() called to signify the end of an asynchronous request. this call is always preceded by a call to onstartrequest(). n...
...from onstartrequest has the side-effect of causing the request to be canceled. void onstartrequest( in nsirequest arequest, in nsisupports acontext ); parameters arequest request being observed. acontext user defined context. onstoprequest() called to signify the end of an asynchronous request. this call is always preceded by a call to onstartrequest(). note: an exception thrown from onstoprequest is generally ignored. void onstoprequest( in nsirequest arequest, in nsisupports acontext, in nsresult astatuscode ); parameters arequest request being observed. acontext user defined context. astatuscode reason for stopping (ns_ok if completed successfully) see also nsistreamlistener ...

nsISHistory
e loads that initiate in session history. getentryatindex() called to obtain handle to the history entry at a given index. nsishentry getentryatindex( in long index, in boolean modifyindex ); parameters index the index value whose entry is requested. modifyindex a boolean flag that indicates if the current index of session history should be modified to the parameter index. exceptions thrown ns_ok history entry for the index is obtained successfully. ns_error_failure error in obtaining history entry for the given index. purgehistory() called to purge older documents from history. documents can be removed from session history for various reasons. for example to control memory usage of the browser, to prevent users from loading documents from history, to erase evidence of prior...
...ple to control memory usage of the browser, to prevent users from loading documents from history, to erase evidence of prior page loads and so on. void purgehistory( in long numentries ); parameters numentries the number of toplevel documents to be purged from history. during purge operation, the latest documents are maintained and older numentries documents are removed from history. exceptions thrown ns_error_failure numentries is invalid or out of bounds with the size of history. ns_success_loss_of_insignificant_data purge was vetoed. reloadcurrententry() void reloadcurrententry(); parameters none. removeshistorylistener() called to remove a listener for the session history component. listeners are notified when pages are loaded from history. note: a listener objec...

nsIScriptError
ull if it's not applicable. read only. timestamp long long elapsed time, in milliseconds, from a platform-specific zero time to the time the message was created. read only. flag constants constant value description errorflag 0x0 error messages. a pseudo-flag for the default, error case. warningflag 0x1 warning messages. exceptionflag 0x2 an exception was thrown for this case - exception-aware hosts can ignore this. strictflag 0x4 one of the flags declared in nsiscripterror. infoflag 0x8 just a log message methods init() initializes the object with information describing the error which occurred. void init( in wstring message, in wstring sourcename, in wstring sourceline,...
...ere are a lot of categories, and they're not all maintained in a single list anywhere in the code. this is an attempt to group them together for reference. note that these are strings. if you want to log an error at chrome level you should set a category from the first section (leaving it empty might log it as content error). as addon author i would recommend using "chrome javascript" for logging exceptions caused by addon code. categories the web console does not display "xpconnect javascript" "component javascript" "chrome javascript" "chrome registration" "xbl" "xbl prototype handler" "xbl content sink" "xbl javascript" "frameconstructor" categories the web console displays "hudconsole" "css parser" "css loader" "content javascript" "dom events" "dom:html" "dom window" "s...

nsIScriptableUnescapeHTML
ue if the fragment is an xml string; otherwise set it to false. baseuri pointer to the base uri against which to resolve any uris included in the fragment. this parameter is ignored if isxml is false. element the nsidomelement to be used as the context node for the purposes of the fragment parsing algorithm. return value an nsidomdocumentfragment of the element with the new text appended. exceptions thrown ns_error_failure unable to append the text to the element. unescape() convents html source into plain text. this is equivalent to calling nsiparserutils::converttoplaintext(src, nsidocumentencoder::outputselectiononly | nsidocumentencoder::outputabsolutelinks, 0). you should call nsiparserutils::converttoplaintext() instead of calling this method. astring unescape( in astring s...
... is equivalent to calling nsiparserutils::converttoplaintext(src, nsidocumentencoder::outputselectiononly | nsidocumentencoder::outputabsolutelinks, 0). you should call nsiparserutils::converttoplaintext() instead of calling this method. astring unescape( in astring src ); parameters src the html string to convert into plain text. return value the result of the plain text conversion. exceptions thrown ns_error_failure unable to convert the string. see also nsidomdocumentfragment nsiuri nsidomelement ...

nsISeekableStream
rameters whence specifies how to interpret the 'offset' parameter in setting the stream offset associated with the implementing stream, according to the table of constants above. offset specifies a value, in bytes, that is used in conjunction with the 'whence' parameter to set the stream offset of the implementing stream. a negative value causes seeking in the reverse direction. exceptions thrown ns_base_stream_closed if called on a closed stream. seteof() this method truncates the stream at the current offset. void seteof(); parameters none. exceptions thrown ns_base_stream_closed if called on a closed stream. tell() this method reports the current offset, in bytes, from the start of the stream. long long tell(); parameters none. return value the current off...
...lled on a closed stream. seteof() this method truncates the stream at the current offset. void seteof(); parameters none. exceptions thrown ns_base_stream_closed if called on a closed stream. tell() this method reports the current offset, in bytes, from the start of the stream. long long tell(); parameters none. return value the current offset, in bytes, from the start of the stream. exceptions thrown ns_base_stream_closed if called on a closed stream. ...

nsIUTF8ConverterService
through the conversion. skipping asciiness/utf8ness check. the most common case is the input is in 7bit non-ascii character sets like iso-2022-jp, hz or utf-7 (in its original form or a modified form used in imap folder names). aallowsubstitution when true, allow the decoder to substitute invalid input sequences by replacement characters. return value the converted string in utf-8. exceptions thrown ns_error_uconv_noconv when there is no decoder for acharset or error code of nsiunicodedecoder in case of conversion failure. converturispectoutf8() ensure that aspec (after url-unescaping it) is encoded in utf-8. if not, convert it to utf-8, assuming it's encoded in acharset, and return the result. make sure that all characters outside us-ascii in your input spec are url-e...
...n unescaped utf-8 and it will be returned without further processing. no valid spec going around in mozilla code would break this assumption. autf8string converturispectoutf8( in acstring aspec, in string acharset ); parameters aspec an url-escaped uri spec to ensure its utf8ness. acharset the character set to convert from if aspec is not in utf-8. return value the converted spec in utf-8. exceptions thrown ns_error_uconv_noconv when there is no decoder for acharset or error code of nsiunicodedecoder in case of conversion failure. ...

nsIUUIDGenerator
rfaces.nsiuuidgenerator); method overview nsidptr generateuuid(); void generateuuidinplace(in nsnonconstidptr id); native code only! methods generateuuid() obtains a new uuid using appropriate platform-specific methods to obtain a nsid that can be considered to be globally unique. nsidptr generateuuid(); parameters none. return value this method returns a nsidptr containing a unique id. exceptions thrown ns_error_failure if a uuid cannot be generated (for example if an underlying source of randomness is not available) native code only!generateuuidinplace obtain a new uuid like the generateuuid() method, but place it in the provided nsid pointer instead of allocating a new nsid. void generateuuidinplace( in nsnonconstidptr id ); parameters id an existing nsid pointer where the uuid w...
...or_failure if a uuid cannot be generated (for example if an underlying source of randomness is not available) native code only!generateuuidinplace obtain a new uuid like the generateuuid() method, but place it in the provided nsid pointer instead of allocating a new nsid. void generateuuidinplace( in nsnonconstidptr id ); parameters id an existing nsid pointer where the uuid will be stored. ...

nsIZipReader
the patterns foo or bar may use the 'pat~pat2' syntax described immediately above. \ will escape a special character. escaping is required for all special characters unless otherwise specified. all other characters match case-sensitively. an apattern not conforming to this syntax has undefined behavior. return value the nsiutf8stringenumerator containing the matching entry names. exceptions thrown ns_error_illegal_value on many but not all invalid apattern values. getcertificateprincipal() returns an object describing the entity which signed an entry. parsemanifest must be called first. if aentryname is an entry in the jar, getinputstream() must be called after parsemanifest. if aentryname is an external file which has meta-information stored in the jar, verifyexternalfile (...
...directory) { var inputstream = zr.getinputstream(entrypointer); reusablestreaminstance.init(inputstream); var filecontents = reusablestreaminstance.read(entry.realsize); console.log('contenst of file=', filecontents); } else { console.log('is directory, no stream to read'); } } } catch (ex) { console.warn('exception occured = ', ex); if (ex.name == 'ns_error_file_not_found') { services.ww.activewindow.alert('xpi at path does not exist!\n\npath = ' + pathtoxpitoread); } } finally { zr.close(); console.log('zr closed'); } see also nsizipentry nsizipwriter ...

XPCOM Interface Reference by grouping
ccessibletable nsiaccessibletext nsiaccessibletreecache nsiaccessiblevalue nsiaccessnode nsisyncmessagesender script nsiscriptableunescapehtml nsiscriptableunicodeconverter nsiscripterror nsiscripterror2 stylesheet nsistylesheetservice url nsiuri nsiurl util nsidomserializer nsidomxpathevaluator nsidomxpathexception nsidomxpathexpression nsidomxpathresult xslt nsixsltexception nsixsltprocessor download nsidownload nsidownloadmanager nsidownloadprogresslistener element internal nsiworker nsiworkerglobalscope nsiworkermessageevent nsiworkermessageport nsiworkerscope tree nsitreeboxobject nsitreecolumn nsitreecolumns ...
... nsiaccelerationlistener nsiaccelerometer misc nsisound nsiwifimonitor document nsiwebnavigation environment nsienvironment event nsieventlistenerinfo nsieventlistenerservice nsieventtarget exception nsiexception extention nsiextensionmanager nsiinstalllocation external nsiexternalprotocolservice frame nsicontentframemessagemanager history nsishentry nsishistory idle nsiidleservice internal ...

Storage
e statement. warning: if you fail to reset a write statement, it will continue to hold a lock on the database preventing future writes or reads. additionally, if you fail to reset a read statement, it will prevent any future writes to the database. in javascript, the language makes it pretty easy to ensure that you always reset a statement. be aware that you should always reset even if an exception is thrown, so your code should look something like this: var statement = dbconn.createstatement("select * from table_name"); try { while (statement.step()) { // use the results... } } finally { statement.reset(); } in c++, storage provides a helper object in storage/public/mozstoragehelper.h, mozstoragestatementscoper, which ensures that the statement object is reset when the object ...
...onous and synchronous statement execution. the best way to deal with this is to only execute your statements asynchronously using mozistorageconnection.executeasync(). this method will manage the transactions for you, so you don't have to worry about them. note: the database engine does not support nested transactions, so attempting to start a transaction when one is already active will throw an exception. transactions can be started with mozistorageconnection.begintransaction() or mozistorageconnection.begintransactionas(). the latter takes one of three constants to describe the type of transaction: mozistorageconnection.transaction_deferred mozistorageconnection.transaction_immediate mozistorageconnection.transaction_exclusive mozistorageconnection.begintransaction() is equivalent to cal...

Getting Started Guide
ddref|s the new one, in the appropriate sequence to avoid the ownership bug mentioned earlier. */ mfooptr = afooptr; additionally, the class using raw xpcom interface pointers will need a destructor to release mfooptr; and a constructor to ensure that mfooptr is initially set to null (or some other reasonable value). nscomptr helps you write code that is leak-proof, exception safe, and significantly less verbose than you would with raw xpcom interface pointers. with nscomptr, you may never have to call addref, release, or queryinterface by hand. you still have to understand xpcom. you still have to know which functions return interface pointers that have already been addrefed and which don't. you still have to ensure your program logic doesn't produce circularly refe...
...s. you should use nscomptr on the stack, where it makes calling queryinterface almost pleasant, and eliminates the complex logic that falls out of error handling. where shouldn't i use nscomptrs? don't use nscomptrs where you don't need an owning reference. see some com ownership guidelines. nscomptr is designed to be used with xpcom interfaces, so don't use it with non-interfaces with specific exceptions described below. don't use nscomptrs in xpcom interfaces. don't use them in plain old c code; nscomptrs are, of course, a c++ only construct. never cast an nscomptr, it's almost guaranteed to leak. nscomptrs for non-interface classes appropriately formatted answer to come, in the meanwhile, the full details are available in this news posting (via google groups). nscomptrs in function signatur...

Using the Gecko SDK
he right way" such that they will remain compatible with future versions of mozilla. for information on how to retrieve and install the gecko sdk, see here. an xpcom component will be compatible with future versions of mozilla if it only makes use of frozen gecko apis. a frozen gecko api is one that is included in the gecko and marked frozen with the text <tt>@status frozen</tt> (with nspr as the exception to the rule). the frozen gecko api consists of a set of component interfaces (c++ vtables) and <tt>extern "c"</tt> symbols exported from the xpcom library and the nspr libraries. the abi of the component interfaces depends on the c++ abi of the host compiler (i.e., the vtable format and calling conventions of the virtual methods may vary from compiler to compiler). the gecko abi is therefore comp...
...orm. the sdk contains headers for all of the frozen interfaces and functions, and it also contains headers for classes and functions defined in the glue libraries. when those classes or functions are used, the component must link with the corresponding static library. every frozen interface or function will be labeled as such in the idl or header file with "@status frozen". (note: nspr is the one exception to this rule. all nspr functions are frozen by default and are not marked as such in the respective header files.) the glue library exists to make common tasks easier. for example, the nscomptr class is defined in the xpcom glue library. if your component does not use any of the glue classes or functions, then you do not need to link against the glue library. work in progress... linking (link li...

Declaring and Using Callbacks
warning: you must store a reference to the callback object as long as the native code might call it. if you don't, the gc might collect the relev...
... warning: you must store a reference to the callback object as long as the native code might call it. ...

Working with data
of the syntax for creating cdata objects without immediately assigning them a value: var mycdataobj = new type; var mycdataobj = new type(); var mycdataobj = type(); these all do the same thing: they return a new cdata object of the specified type, whose data buffer has been populated entirely with zeroes. note: if type.size is undefined, creating a new object this way will throw a typeerror exception. creating initialized cdata objects similarly, you can initialize cdata objects with specific values at the type of creation by specifying them as a parameter when calling the ctype's constructor, like this: var mycdataobj = new type(value); var mycdataobj = type(value); if the size of the specified type isn't undefined, the specified value is converted to the given type. if the conversion i...
... ...

CData
tostring() properties properties of all cdata objects property type description constructor ctype the data type of the cdata object, as a ctype. read only. note: this is never ctypes.void_t or an array type with an unspecified length. value object the javascript equivalent of the cdata object's value. this will throw a typeerror exception if the value can't be converted. methods available on all cdata objects address() returns a cdata object of the pointer type ctypes.pointertype(dataobject.constructor) whose value points to the c object referred to by the object. this provides a way to get a pointer to the actual data of the c value represented by the cdata object. cdata address() parameters none. return value a cd...
...string identifying the data. methods available on string objects these methods must be called on objects that are arrays or pointers to 8-bit or 16-bit character or integer types, terminated by a null character. readstring() converts a character array to a javascript string. 8-bit strings are assumed to be encoded as utf-8. if the 8-bit string contains invalid encoded character, a typeerror exception is thrown. string readstring(); parameters none. return value a new string object that is a copy of the original string contents. readstringreplacemalformed() converts a character array to a javascript string. 8-bit strings are assumed to be encoded as utf-8. if the 8-bit string contains invalid encoded character, no exception is thrown. string readstringreplacemalformed(); parameter...

FunctionType
ction; this is one of the abi constants. returntype a ctype indicating the type of the value returned by the function. argtype1... argtypen zero or more ctype objects indicating the types of each of the parameters passed into the c function. return value a ctype describing the function type. the equivalent c function type declaration would be: returntype (*) ([argtype1, ..., argtypen]); exceptions thrown typeerror abi is not a valid abi constants, or returntype or any of the argument types are not valid ctype objects. properties property type description abi one of the abi constants the abi of the function. read only. argtypes ctype[] a sealed array of the argument types. read only. returntype ctype the return type of the ...
... ctype array([n]) string tosource() string tostring() functiontype cdata functiontype cdata cannot be constructed. function pointer is created with functiontype.ptr. cdata functiontype.ptr([func]); functiontype is functiontype ctype. parameters func a pointer value or javascript function. return value a cdata representing the newly allocated function pointer. exceptions thrown typeerror func is not either pointer value or javascript function. see also ctype cdata abi library type conversion ...

Tutorial: Show Allocations Per Call Path - Firefox Developer Tools
ebuggertoglobal(window); (function () { // the debugger we'll use to observe a tab's allocation. var dbg; // start measuring the selected tab's main window's memory // consumption. this function is available in the browser // console. window.demotrackallocations = function() { dbg = new debugger; // this makes hacking on the demo *much* more // pleasant. dbg.uncaughtexceptionhook = handleuncaughtexception; // find the current tab's main content window. var w = gbrowser.selectedbrowser.contentwindow; console.log("tracking allocations in page: " + w.location.href); // make that window a debuggee of our debugger. dbg.adddebuggee(w.wrappedjsobject); // enable allocation tracking in dbg's debuggees. dbg.memory.trackingallocati...
...ow.demoplotallocations = function() { // grab the allocation log. var log = dbg.memory.drainallocationslog(); // neutralize the debugger, and drop it on the floor // for the gc to collect. console.log("stopping allocation tracking."); dbg.removealldebuggees(); dbg = undefined; // analyze and display the allocation log. plot(log); } function handleuncaughtexception(ex) { console.log('debugger hook threw:'); console.log(ex.tostring()); console.log('stack:'); console.log(ex.stack); }; function plot(log) { // given the log, compute a map from allocation sites to // allocation counts. note that stack entries are '===' if // they represent the same site with the same callers. var counts = new map; for (let site of log) { ...

Debugger.Object - Firefox Developer Tools
the descriptions use "referent" to mean "the referent of this debugger.object instance". unless otherwise specified, these methods are not invocation functions; if a call would cause debuggee code to run (say, because it gets or sets an accessor property whose handler is debuggee code, or because the referent is a proxy whose traps are debuggee code), the call throws a debugger.debuggeewouldrun exception. getproperty(name) return the value of the referent's property namedname, or undefined if it has no such property.name must be a string. the result is a debuggee value. setproperty(name,value) storevalue as the value of the referent's property namedname, creating the property if it does not exist.name must be a string;value must be a debuggee value. getownpropertydescriptor(name) ...
... evalinglobal(code, [options]) if the referent is a global object, evaluatecode in that global environment, and return a completion value describing how it completed.code is a string. all extant handler methods, breakpoints, watchpoints, and so on remain active during the call. this function follows the invocation function conventions. if the referent is not a global object, throw a typeerror exception. codeis interpreted as strict mode code when it contains a use strict directive. ifcode is not strict mode code, then variable declarations incode affect the referent global object. (in the terms used by the ecmascript specification, the variableenvironment of the execution context for the eval code is the referent.) theoptions argument is as for debugger.frame.prototype.eval. evalinglob...

Animation.finish() - Web APIs
ent playback time to the end of the animation corresponding to the current playback direction. that is, if the animation is playing forward, it sets the playback time to the length of the animation sequence, and if the animation is playing in reverse (having had its reverse() method called), it sets the playback time to 0. syntax animation.finish(); parameters none. return value none. exceptions invalidstate the player's playback rate is 0 or the animation's playback rate is greater than 0 and the end time of the animation is infinity. examples the following example shows how to use the finish() method and catch an invalidstate error. interfaceelement.addeventlistener("mousedown", function() { try { player.finish(); } catch(e if e instanceof invalidstate) { console.l...
...an 0 and the end time of the animation is infinity. examples the following example shows how to use the finish() method and catch an invalidstate error. interfaceelement.addeventlistener("mousedown", function() { try { player.finish(); } catch(e if e instanceof invalidstate) { console.log("finish() called on paused or finished animation."); } catch(e); logmyerrors(e); //pass exception object to error handler } }); the following example finishes all the animations on a single element, regardless of their direction of playback. elem.getanimations().foreach( function(animation){ return animation.finish(); } ); specifications specification status comment web animationsthe definition of 'finish()' in that specification. working draft ...

AudioContext() - Web APIs
of audiocontext.baselatency to determine the true latency after creating the context. samplerate optional the samplerate to be used by the audiocontext, specified in samples per second. the value may be any value supported by audiobuffer. if not specified, the preferred sample rate for the context's output device is used by default. return value the newly constructed audiocontext instance. exceptions notsupportederror the specified samplerate isn't supported by the context. usage notes the specification doesn't go into a lot of detail about things like how many audio contexts a user agent should support, or minimum or maximum latency requirements (if any), so these details can vary from browser to browser. be sure to check the values if they matter to you. in particular, the specific...
...lues if they matter to you. in particular, the specification doesn't indicate a maximum or minimum number of audio contexts that must be able to be open at the same time, so this is left up to the browser implementations to decide. google chrome per-tab audio context limitation in chrome prior to version 66 google chrome only supported up to six audio contexts per tab at a time. non-standard exceptions in chrome if the value of the latencyhint property isn't valid, chrome throws a typeerror exception with the message "the provided value '...' is not a valid enum value of type audiocontextlatencycategory". example this example creates a new audiocontext for interactive audio (optimizing for latency) and a sample rate of 44.1khz. var audiocontext = window.audiocontext || window.webkitaudioc...

AudioNode.connect() - Web APIs
stination you want to connect the current audionode to; the default is 0. the index numbers are defined according to the number of input channels (see audio channels). it is possible to connect an audionode to another audionode, which in turn connects back to the first audionode, creating a cycle. this is allowed only if there is at least one delaynode in the cycle. ...
... invalidaccesserror the destination node is not part of the same audio context as the source node. ...

AudioParam.setValueCurveAtTime() - Web APIs
iven interval starting at starttime and a specific duration. syntax var paramref = param.setvaluecurveattime(values, starttime, duration); parameters values an array of floating-point numbers representing the value curve the audioparam will change through along the specified duration. every value in the array must be a finite number; if any value is nan, infinity, or -infinity, a typeerror exception is thrown. starttime a double representing the time (in seconds) after the audiocontext was first created that the change in value will happen. if this value is lower than audiocontext.currenttime, it is clamped to currenttime. duration a double representing the total time (in seconds) over which the parameter's value will change following the specified curve. the specified values are spaced ...
...alue is lower than audiocontext.currenttime, it is clamped to currenttime. duration a double representing the total time (in seconds) over which the parameter's value will change following the specified curve. the specified values are spaced equally along this duration. return value a reference to this audioparam object. some older browser implementations of this interface return undefined. exceptions invalidstateerror the specified array of values has fewer than 2 items in it. rangeerror the specified starttime is either negative or a non-finite value, or duration is not a finite, strictly positive number. typeerror one or more of the values in the values array is non-finite. non-finite values are nan, infinity, and -infinity. usage notes when the parameter's value finishes follow...

CSSPrimitiveValue.getFloatValue() - Web APIs
syntax var floatvalue = cssprimitivevalue.getfloatvalue(unit); parameters unittype an unsigned short representing the code for the unit type, in which the value should be returned. valid values are: constant description css_cm the value is a <length> in centimeters. ...
...s_pc the value is a <length> in picas. css_percentage the value is a <percentage>. css_pt the value is a <length> in points. css_px the value is a <length> in pixels. css_rad the value is an <angle> in radians. css_s the value is a <time> in seconds. return value a float value in the specified unit. exceptions type description domexception an invalid_access_err is raised if the css value doesn't contain a float value or if the float value can't be converted into the specified unit. example var cs = window.getcomputedstyle(document.body); var cssvalue = cs.getpropertycssvalue("margin-top"); console.log(cssvalue.getfloatvalue(cssprimitivevalue.css_cm)); specificatio...

CSSPrimitiveValue.setFloatValue() - Web APIs
syntax cssprimitivevalue.setfloatvalue(unittype, floatvalue); parameters unittype an unsigned short representing the code for the unit type, in which the value should be returned. valid values are: constant description css_cm the value is a <length> in centimeters. ...
...<length> in picas. css_percentage the value is a <percentage>. css_pt the value is a <length> in points. css_px the value is a <length> in pixels. css_rad the value is an <angle> in radians. css_s the value is a <time> in seconds. floatvalue a float representing the new float value. return value void. exceptions type description domexception an invalid_access_err is raised if the css value doesn't contain a float value or if the string value can't be converted into the specified unit. an no_modification_allowed_err is raised if this property is read-only. specifications specification status comment document object model (dom) level 2 style...

CSSPrimitiveValue.setStringValue() - Web APIs
the setstringvalue() method of the cssprimitivevalue interface is used to set a string value. if the property attached to this value can't accept the specified unit or the string value, the value will be unchanged and a domexception will be raised. syntax cssprimitivevalue.setstringvalue(stringtype, stringvalue); parameters stringtype an unsigned short representing the type of the value. possible values are: constant description css_attr the value is an attr() function. css_ident the value is an identifier. ...
...representing the type of the value. possible values are: constant description css_attr the value is an attr() function. css_ident the value is an identifier. css_string the value is a <string>. css_uri the value is a <uri>. stringvalue a domstring representing the new string value. return value void. exceptions type description domexception an invalid_access_err is raised if the css value doesn't contain a string value or if the string value can't be converted into the specified unit. an no_modification_allowed_err is raised if this property is read-only. specifications specification status comment document object model (dom) level 2 styl...

Cache - Web APIs
. (see selective caching live) the code uses cachestorage.open() to open any cache objects with a content-type header that starts with font/. the code then uses cache.match() to see if there's already a matching font in the cache, and if so, returns it. if there isn't a matching font, the code fetches the font from the network and uses cache.put() to cache the fetched resource. the code handles exceptions thrown from the fetch() operation. note that an http error response (e.g., 404) will not trigger an exception. it will return a normal response object that has the appropriate error code. the code snippet also shows a best practice for versioning caches used by the service worker. though there's only one cache in this example, the same approach can be used for multiple caches. it maps a shortha...
...to', event.request.url); cache.put(event.request, response.clone()); } else { console.log(' not caching the response to', event.request.url); } // return the original response object, which will be used to fulfill the resource request. return response; }); }).catch(function(error) { // this catch() will handle exceptions that arise from the match() or fetch() operations. // note that a http error response (e.g. 404) will not trigger an exception. // it will return a normal response object that has the appropriate error code set. console.error(' error in fetch handler:', error); throw error; }); }) ); }); storing cookies in caches the fetch api requires set-cookie h...

ClipboardItem.getType() - Web APIs
typeerror no parameter is specified or the type is not that of the clipboarditem. ...
... typeerror no parameter is specified or the type is not that of the clipboarditem. ...

DOMMatrixReadOnly - Web APIs
. for a 2d matrix, the elements a through f are listed, for a total of six values and the form matrix(a, b, c, d, e, f). for a 3d matrix, the returned string contains all 16 elements and takes the form matrix3d(m11, m12, m13, m14, m21, m22, m23, m24, m31, m32, m33, m34, m41, m42, m43, m44). see the css matrix3d() function for details on the 3d notation's syntax. throws an invalidstateerror exception if any of the elements in the matrix are non-finite (even if, in the case of a 2d matrix, the non-finite values are in elements not used by the 2d matrix representation). dommatrixreadonly.transformpoint() transforms the specified point using the matrix, returning a new dompoint object containing the transformed point. neither the matrix nor the original point are altered. dommatrixreadonly.
..., the vector is (0, 0, 0). the original matrix is not changed. static methods this interface inherits methods from dommatrixreadonly. fromfloat32array() creates a new mutable dommatrix object given an array of single-precision (32-bit) floating-point values. if the array has six values, the result is a 2d matrix; if the array has 16 values, the result is a 3d matrix. otherwise, a typeerror exception is thrown. fromfloat64array() creates a new mutable dommatrix object given an array of double-precision (64-bit) floating-point values. if the array has six values, the result is a 2d matrix; if the array has 16 values, the result is a 3d matrix. otherwise, a typeerror exception is thrown. frommatrix() creates a new mutable dommatrix object given an existing matrix or a dommatrixinit dictiona...

Document.querySelector() - Web APIs
th-first pre-order traversal of the document's nodes starting with the first element in the document's markup and iterating through sequential nodes by order of the number of child nodes. syntax element = document.queryselector(selectors); parameters selectors a domstring containing one or more selectors to match. this string must be a valid css selector string; if it isn't, a syntax_err exception is thrown. see locating dom elements using selectors for more about selectors and how to manage them. note: characters that are not part of standard css syntax must be escaped using a backslash character. since javascript also uses backslash escaping, be especially careful when writing string literals using these characters. see escaping special characters for more information. return value ...
...when writing string literals using these characters. see escaping special characters for more information. return value an htmlelement object representing the first element in the document that matches the specified set of css selectors, or null is returned if there are no matches. if you need a list of all elements matching the specified selectors, you should use queryselectorall() instead. exceptions syntax_err the syntax of the specified selectors is invalid. usage notes if the specified selector matches an id that is incorrectly used more than once in the document, the first element with that id is returned. css pseudo-elements will never return any elements, as specified in the selectors api. escaping special characters to match against an id or selectors that do not follow stan...

Document.querySelectorAll() - Web APIs
ist of the document's elements that match the specified group of selectors. note: this method is implemented based on the parentnode mixin's queryselectorall() method. syntax elementlist = parentnode.queryselectorall(selectors); parameters selectors a domstring containing one or more selectors to match against. this string must be a valid css selector string; if it's not, a syntaxerror exception is thrown. see locating dom elements using selectors for more information about using selectors to identify elements. multiple selectors may be specified by separating them using commas. note: characters which are not part of standard css syntax must be escaped using a backslash character. since javascript also uses backslash escaping, special care must be taken when writing string literals us...
...t be taken when writing string literals using these characters. see escaping special characters for more information. return value a non-live nodelist containing one element object for each element that matches at least one of the specified selectors or an empty nodelist in case of no matches. note: if the specified selectors include a css pseudo-element, the returned list is always empty. exceptions syntaxerror the syntax of the specified selectors string is not valid. examples obtaining a list of matches to obtain a nodelist of all of the <p> elements in the document: var matches = document.queryselectorall("p"); this example returns a list of all <div> elements within the document with a class of either note or alert: var matches = document.queryselectorall("div.note, div.alert...

Document - Web APIs
has special meaning in privileged javascript code (with universalxpconnect privileges). document.popupnode returns the node upon which a popup was invoked. document.tooltipnode returns the node which is the target of the current tooltip. ...
... internet explorer notes microsoft defines some non-standard properties: document.filesize* returns size in bytes of the document. starting with internet explorer 11, that property is no longer supported. see msdn. ...

Document Object Model (DOM) - Web APIs
ture, style, or content. nodes can also have event handlers attached to them. once an event is triggered, the event handlers get executed. to learn more about what the dom is and how it represents documents, see our article introduction to the dom. ...
...eger svganimatedlength svganimatedlengthlist svganimatednumber svganimatednumberlist svganimatedpathdata svganimatedpoints svganimatedpreserveaspectratio svganimatedrect svganimatedstring svganimatedtransformlist smil-related interfaces elementtimecontrol timeevent other svg interfaces getsvgdocument shadowanimation svgcolorprofilerule svgcssrule svgdocument svgexception svgexternalresourcesrequired svgfittoviewbox svglangspace svglocatable svgrenderingintent svgstylable svgtests svgtransformable svgunittypes svguseelementshadowroot svgurireference svgviewspec svgzoomandpan svgzoomevent specifications specification status comment dom living standard ...

Element.outerHTML - Web APIs
n element, use the innerhtml property instead. syntax var content = element.outerhtml; element.outerhtml = htmlstring; value reading the value of outerhtml returns a domstring containing an html serialization of the element and its descendants. setting the value of outerhtml replaces the element and all of its descendants with a new dom tree constructed by parsing the specified htmlstring. exceptions syntaxerror an attempt was made to set outerhtml using an html string which is not valid. nomodificationallowederror an attempt was made to set outerhtml on an element which is a direct child of a document, such as document.documentelement. examples getting the value of an element's outerhtml property: html <div id="d"> <p>content</p> <p>further elaborated</p> </div> javascript ...
....firstchild.nodename); // logs "div" d.outerhtml = "<p>this paragraph replaced the original div.</p>"; console.log(container.firstchild.nodename); // logs "p" // the #d div is no longer part of the document tree, // the new paragraph replaced it. notes if the element has no parent element, setting its outerhtml property will not change it or its descendants. many browsers will also throw an exception. for example: var div = document.createelement("div"); div.outerhtml = "<div class=\"test\">test</div>"; console.log(div.outerhtml); // output: "<div></div>" also, while the element will be replaced in the document, the variable whose outerhtml property was set will still hold a reference to the original element: var p = document.getelementsbytagname("p")[0]; console.log(p.nodename); // shows:...

Element.querySelector() - Web APIs
eryselector() method of the element interface returns the first element that is a descendant of the element on which it is invoked that matches the specified group of selectors. syntax element = baseelement.queryselector(selectors); parameters selectors a group of selectors to match the descendant elements of the element baseelement against; this must be valid css syntax, or a syntaxerror exception will occur. the first element found which matches this group of selectors is returned. return value the first descendant element of baseelement which matches the specified group of selectors. the entire hierarchy of elements is considered when matching, including those outside the set of elements including baseelement and its descendants; in other words, selectors is first applied to the whole...
...aseelement and its descendants; in other words, selectors is first applied to the whole document, not the baseelement, to generate an initial list of potential elements. the resulting elements are then examined to see if they are descendants of baseelement. the first match of those remaining elements is returned by the queryselector() method. if no matches are found, the returned value is null. exceptions syntaxerror the specified selectors are invalid. examples let's consider a few examples. find a specific element with specific values of an attribute in this first example, the first <style> element which either has no type or has type "text/css" in the html document body is returned: var el = document.body.queryselector("style[type='text/css'], style:not([type])"); the entire hierar...

Element.querySelectorAll() - Web APIs
ectors which are descendants of the element on which the method was called. note: this method is implemented based on the parentnode mixin's queryselectorall() method. syntax elementlist = parentnode.queryselectorall(selectors); parameters selectors a domstring containing one or more selectors to match against. this string must be a valid css selector string; if it's not, a syntaxerror exception is thrown. see locating dom elements using selectors for more information about using selectors to identify elements. multiple selectors may be specified by separating them using commas. note: characters which are not part of standard css syntax must be escaped using a backslash character. since javascript also uses backspace escaping, special care must be taken when writing string literals us...
...ackspace escaping, special care must be taken when writing string literals using these characters. see escaping special characters for more information. return value a non-live nodelist containing one element object for each descendant node that matches at least one of the specified selectors. note: if the specified selectors include a css pseudo-element, the returned list is always empty. exceptions syntaxerror the syntax of the specified selectors string is not valid. examples dataset selector & attribute selectors <section class="box" id="sect1"> <div class="funnel-chart-percent1">10.900%</div> <div class="funnel-chart-percent2">3700.00%</div> <div class="funnel-chart-percent3">0.00%</div> </section> // dataset selectors const refs = [...document.queryselectorall(`[data-na...

Element.requestFullscreen() - Web APIs
ol the behavior of the transition to full-screen mode. currently, the only option is navigationui, which controls whether or not to show navigation ui while the element is in full-screen mode. the default value is "auto", which indicates that the browser should decide what to do. return value a promise which is resolved with a value of undefined when the transition to full screen is complete. ...
...reen mode. currently, the only option is navigationui, which controls whether or not to show navigation ui while the element is in full-screen mode. the default value is "auto", which indicates that the browser should decide what to do. return value a promise which is resolved with a value of undefined when the transition to full screen is complete. exceptions rather than throw a traditional exception, the requestfullscreen() procedure announces error conditions by rejecting the promise it has returned. the rejection handler receives one of the following exception values: typeerror the typeerror exception may be delivered in any of the following situations: the document containing the element isn't fully active; that is, it's not the current active document. the element is not contai...

Event.initEvent() - Web APIs
full support yesedge full support 12firefox full support 17 full support 17 no support ? ...
...not for use in new websites.

FileSystemDirectoryEntry.getDirectory() - Web APIs
for androidsafari on iossamsung internetgetdirectory experimentalchrome full support 8edge full support 79firefox full support 50notes full support 50notes notes in firefox, the errorcallback's input parameter is a domexception rather than a fileerror object.ie no support noopera no support nosafari full support 11.1webview android full support ≤37chrome android full support 18firefox android ...
...t 11.1webview android full support ≤37chrome android full support 18firefox android full support 50notes full support 50notes notes in firefox, the errorcallback's input parameter is a domexception rather than a fileerror object.opera android no support nosafari ios full support 11.3samsung internet android full support yeslegend full support full support n...

FileSystemDirectoryEntry.getFile() - Web APIs
opera for androidsafari on iossamsung internetgetfile experimentalchrome full support 8edge full support 79firefox full support 50notes full support 50notes notes in firefox, the errorcallback's input parameter is a domexception rather than a fileerror object.ie no support noopera no support nosafari full support 11.1webview android full support ≤37chrome android full support 18firefox android ...
...t 11.1webview android full support ≤37chrome android full support 18firefox android full support 50notes full support 50notes notes in firefox, the errorcallback's input parameter is a domexception rather than a fileerror object.opera android no support nosafari ios full support 11.3samsung internet android full support yeslegend full support full support n...

HTMLMediaElement.play() - Web APIs
s been successfully started. failure to begin playback for any reason, such as permission issues, result in the promise being rejected. syntax var promise = htmlmediaelement.play(); parameters none. return value a promise which is resolved when playback has been started, or is rejected if for any reason playback cannot be started. note: older browsers may not return a value from play(). exceptions the promise's rejection handler is called with an exception name passed in as its sole input parameter (as opposed to a traditional exception being thrown). possible errors include: notallowederror the user agent (browser) or operating system doesn't allow playback of media in the current context or situation. this may happen, for example, if the browser requires the user to explicitly star...
...t (browser) or operating system doesn't allow playback of media in the current context or situation. this may happen, for example, if the browser requires the user to explicitly start media playback by clicking a "play" button. notsupportederror the media source (which may be specified as a mediastream, mediasource, blob, or file, for example) doesn't represent a supported media format. other exceptions may be reported, depending on browser implementation details, media player implementation, and so forth. usage notes although the term "autoplay" is usually thought of as referring to pages that immediately begin playing media upon being loaded, web browsers' autoplay policies also apply to any script-initiated playback of media, including calls to play(). if the user agent is configured not ...

HTMLMediaElement - Web APIs
k objects contained in the element. htmlmediaelement.autoplay a boolean that reflects the autoplay html attribute, indicating whether playback should automatically begin as soon as enough media is available to do so without interruption. note: automatically playing audio when the user doesn't expect or desire it is a poor user experience and should be avoided in most cases, though there are exceptions. see the autoplay guide for media and web audio apis for more information. keep in mind that browsers may ignore autoplay requests, so you should ensure that your code isn't dependent on autoplay working. htmlmediaelement.buffered read only returns a timeranges object that indicates the ranges of the media source that the browser has buffered (if any) at the moment the buffered property is ...
... in the framebuffer of each mozaudioavailable event. this number is a total for all channels, and by default is set to be the number of channels * 1024 (e.g., 2 channels * 1024 samples = 2048 total). the mozframebufferlength property can be set to a new value for lower latency, larger amounts of data, etc. the size given must be a number between 512 and 16384. using any other size results in an exception being thrown. the best time to set a new length is after the loadedmetadata event fires, when the audio info is known, but before the audio has started or mozaudioavailable events have begun firing. htmlmediaelement.mozsamplerate read only returns a double representing the number of samples per second that will be played. for example, 44100 samples per second is the sample rate used by c...

HTMLSelectElement.add() - Web APIs
tion elements for this select element. syntax collection.add(item[, before]); parameters item is an htmloptionelement or htmloptgroupelement before is optional and an element of the collection, or an index of type long, representing the item item should be inserted before. if this parameter is null (or the index does not exist), the new element is appended to the end of the collection. exceptions a domerror of the type hierarchyrequesterror if the item passed to the method is an ancestor of the htmlselectelement. examples creating elements from scratch var sel = document.createelement("select"); var opt1 = document.createelement("option"); var opt2 = document.createelement("option"); opt1.value = "1"; opt1.text = "option: value 1"; opt2.value = "2"; opt2.text = "option: value 2"...
... before can now be a long and is optional. it throws a domerror of the type hierarchyrequesterror if the passed item is an ancestor of the htmlselectelement and no longer throws if the before parameter is not found. document object model (dom) level 2 html specificationthe definition of 'htmlselectelement.add()' in that specification. obsolete the method now throws an not_found_err exception if the item of the before parameter is not a child of this element. document object model (dom) level 1 specificationthe definition of 'htmlselectelement.add()' in that specification. obsolete initial definition ...

HTMLTableRowElement - Web APIs
reflects the valign attribute and can have one of the following values: "top", "middle", "bottom", or "baseline". methods inherits methods from its parent, htmlelement. htmltablerowelement.deletecell() removes the cell at the given position in the row. if the given position is greater (or equal as it starts at zero) than the amount of cells in the row, or is smaller than 0, it raises a domexception with the indexsizeerror value. htmltablerowelement.insertcell() inserts a new cell just before the given position in the row. if the given position is not given or is -1, it appends the cell to the row. if the given position is greater (or equal as it starts at zero) than the amount of cells in the row, or is smaller than -1, it raises a domexception with the indexsizeerror value. returns a ref...
...n of 'htmltablerowelement' in that specification. recommendation the parameter of insertcell is now optional and default to -1. document object model (dom) level 2 html specificationthe definition of 'htmltablerowelement' in that specification. obsolete the cells, rowindex, and selectionrowindex properties are now read-only. the methods insertcell and deletecell can raise exceptions. document object model (dom) level 1 specificationthe definition of 'htmltablerowelement' in that specification. obsolete initial definition. ...

History.pushState() - Web APIs
ate object. the state object can be anything that can be serialized. because firefox saves state objects to the user's disk so they can be restored after the user restarts the browser, we impose a size limit of 640k characters on the serialized representation of a state object. if you pass a state object whose serialized representation is larger than this to pushstate(), the method will throw an exception. if you need more space than this, you're encouraged to use sessionstorage and/or localstorage. title most browsers currently ignore this parameter, although they may use it in the future. passing the empty string here should be safe against future changes to the method. alternatively, you could pass a short title for the state to which you're moving. url optional the new history entry's url ...
...given by this parameter. note that the browser won't attempt to load this url after a call to pushstate(), but it might attempt to load the url later, for instance after the user restarts the browser. the new url does not need to be absolute; if it's relative, it's resolved relative to the current url. the new url must be of the same origin as the current url; otherwise, pushstate() will throw an exception. if this parameter isn't specified, it's set to the document's current url. description in a sense, calling pushstate() is similar to setting window.location = "#foo", in that both will also create and activate another history entry associated with the current document. but pushstate() has a few advantages: the new url can be any url in the same origin as the current url. in contrast, setti...

IDBDatabase.transaction() - Web APIs
u can specify its name as a string. therefore the following lines are equivalent: var transaction = db.transaction(['my-store-name']); var transaction = db.transaction('my-store-name'); if you need to access all object stores in the database, you can use the property idbdatabase.objectstorenames: var transaction = db.transaction(db.objectstorenames); passing an empty array will throw an exception. mode optional the types of access that can be performed in the transaction. transactions are opened in one of three modes: readonly, readwrite and readwriteflush (non-standard, firefox-only.) versionchange mode can't be specified here. if you don't provide the parameter, the default access mode is readonly. to avoid slowing things down, don't open a readwrite transaction unless you actually ne...
...k before delivering the complete event by creating a transaction using the experimental (non-standard) readwriteflush mode (see idbdatabase.transaction.) this is currently experimental, and can only be used if the dom.indexeddb.experimental pref is set to true in about:config. details optional dictionary of other settings, supported only by chrome: return value an idbtransaction object. exceptions this method may raise a domexception of one of the following types: exception description invalidstateerror the close() method has previously been called on this idbdatabase instance. notfounderror an object store specified in in the storenames parameter has been deleted or removed. typeerror the value for the mode parameter is inval...

IDBFactory.cmp() - Web APIs
s. note: do not use this method for comparing arbitrary javascript values, because many javascript values are either not valid indexeddb keys (booleans and objects, for example) or are treated as equivalent indexeddb keys (for example, since indexeddb ignores arrays with non-numeric properties and treats them as empty arrays, so any non-numeric arrays are treated as equivalent). this throws an exception if either of the values is not a valid key. syntax var result = indexeddb.cmp(first, second); parameters first the first key to compare. second the second key to compare. return value an integer that indicates the result of the comparison; the table below lists the possible values and their meanings: returned value description -1 1st key is less than the 2nd ...
...rs first the first key to compare. second the second key to compare. return value an integer that indicates the result of the comparison; the table below lists the possible values and their meanings: returned value description -1 1st key is less than the 2nd key 0 1st key is equal to the 2nd key 1 1st key is greater than the 2nd key exceptions this method may raise a domexception of the following types: attribute description dataerror one of the supplied keys was not a valid key. example var a = 1; var b = 2; var result = window.indexeddb.cmp(a, b); console.log( "comparison results: " + result ); specifications specification status comment indexed database api 2.0the defin...

IDBIndex.getAll() - Web APIs
.getall(query, count); parameters query optional a key or an idbkeyrange identifying the records to retrieve. if this value is null or missing, the browser will use an unbound key range. count optional the number records to return. if this value exceeds the number of records in the query, the browser will only retrieve the first item. if it is lower than 0 or greater than 232-1 a typeerror exception will be thrown. return value an idbrequest object on which subsequent events related to this operation are fired. exceptions this method may raise a domexception of the following types: exception description transactioninactiveerror this idbindex's transaction is inactive. invalidstateerror the idbindex has been deleted or removed. a typeerror ...
... will be thrown. return value an idbrequest object on which subsequent events related to this operation are fired. exceptions this method may raise a domexception of the following types: exception description transactioninactiveerror this idbindex's transaction is inactive. invalidstateerror the idbindex has been deleted or removed. a typeerror exception is thrown if the count parameter is not between 0 and 232-1 included. example var myindex = objectstore.index('index'); var getallrequest = myindex.getall(); getallrequest.onsuccess = function() { console.log(getallrequest.result); } specification specification status comment indexed database api draftthe definition of 'getall()' in that specification. recommendat...

IDBIndex.getAllKeys() - Web APIs
getallkeys(query, count); parameters query optional a key or an idbkeyrange identifying the keys to retrieve. if this value is null or missing, the browser will use an unbound key range. count optional the number records to return. if this value exceeds the number of records in the query, the browser will only retrieve the first item. if it is lower than 0 or greater than 232-1 a typeerror exception will be thrown. return value an idbrequest object on which subsequent events related to this operation are fired. exceptions this method may raise a domexception of the following types: exception description transactioninactiveerror this idbindex's transaction is inactive. invalidstateerror the idbindex has been deleted or removed. a type...
...be thrown. return value an idbrequest object on which subsequent events related to this operation are fired. exceptions this method may raise a domexception of the following types: exception description transactioninactiveerror this idbindex's transaction is inactive. invalidstateerror the idbindex has been deleted or removed. a typeerror exception is thrown if the count parameter is not between 0 and 232-1 included. example var myindex = objectstore.index('index'); var getallkeysrequest = myindex.getallkeys(); getallkeysrequest.onsuccess = function() { console.log(getallkeysrequest.result); } specification specification status comment indexed database api draftthe definition of 'getall()' in that specificatio...

IDBIndex.name - Web APIs
invalidstateerror the index, or its object store, has been deleted; or the current transaction is not an upgrade transaction. ...
... invalidstateerror the index, or its object store, has been deleted; or the current transaction is not an upgrade transaction. ...

IDBObjectStore.getAll() - Web APIs
request = objectstore.getall(query); var request = objectstore.getall(query, count); parameters query optional a key or idbkeyrange to be queried. if nothing is passed, this will default to a key range that selects all the records in this object store. count optional specifies the number of values to return if more than one is found. if it is lower than 0 or greater than 232-1 a typeerror exception will be thrown. return value an idbrequest object on which subsequent events related to this operation are fired. exceptions this method may raise a domexception of one of the following types: exception description transactioninactiveerror this idbobjectstore's transaction is inactive. dataerror the key or key range provided contains an invalid k...
... specifications specification status comment indexed database api draftthe definition of 'getall()' in that specification. ...

IDBTransaction.error - Web APIs
the exact error is one of serveral possibilities. ...
...a android full support 14safari ios full support 8samsung internet android full support 1.5 full support 1.5 no support 1.5 — 7.0prefixed prefixed implemented with the vendor prefix: webkitdomexception value instead of domerrorchrome full support 48edge full support ≤18firefox full support 58ie no support noopera full support yessafari no support ...

IDBTransaction - Web APIs
t callback: abort due to bad requests, e.g. trying to add() the same key twice, or put() with the same index key with a uniqueness constraint. this causes an error on the request, which can bubble up to an error on the transaction, which aborts the transaction. this can be prevented by using preventdefault() on the error event on the request. an explicit abort() call from script. an uncaught exception in the request's success/error handler. an i/o error (e.g. an actual failure to write to disk, or other os/hardware failure). quota exceeded. a user agent crash. firefox durability guarantees note that as of firefox 40, indexeddb transactions have relaxed durability guarantees to increase performance (see bug 1112702.) previously in a readwrite transaction idbtransaction.oncomplete was fire...
...itical data that cannot be recomputed later) you can force a transaction to flush to disk before delivering the complete event by creating a transaction using the experimental (non-standard) readwriteflush mode (see idbdatabase.transaction. properties idbtransaction.db read only the database connection with which this transaction is associated. idbtransaction.error read only returns a domexception indicating the type of error that occured when there is an unsuccessful transaction. this property is null if the transaction is not finished, is finished and successfully committed, or was aborted with theidbtransaction.abort() function. idbtransaction.mode read only the mode for isolating access to data in the object stores that are in the scope of the transaction. the default value is reado...

KeyframeEffect.setKeyframes() - Web APIs
only specified the end state of the animation, and the beginning state is implied. attributes keyframes may specify property-value pairs for any of the animatable css properties. the property names are specified using camel-case so for example background-color becomes backgroundcolor and background-position-x becomes backgroundpositionx. shorthand values such as margin are also permitted. two exceptional css properties are: float, which must be written as cssfloat since "float" is a reserved word in javascript. it's just for reference here, this will have no effect on animation since "float" is not an animatable css property. offset, which must be written as cssoffset since "offset" represents the keyframe offset as described below. the following special attributes may also be specified: ...
...yframe will be evenly spaced between adjacent keyframes. easing the timing function used from this keyframe until the next keyframe in the series. composite the keyframeeffect.composite operation used to combine the values specified in this keyframe with the underlying value. this will be auto if the composite operation specified on the effect is being used. return value void. exceptions exception explanation typeerror one or more of the frames were not of the correct type of object, the keyframes were not loosely sorted by offset, or a keyframe existed with an offset of less than 0 or more than 1. note: if the keyframes cannot be processed or are malformed, the keyframeeffect's keyframes are not modified. examples // passing an array of k...

LocalFileSystem - Web APIs
ent is the filesystem object with two properties: name - the unique name assigned by the browser to the file system. root - the read-only directoryentry object representing the root of the file system. opt_errorcallback the error callback that is called when errors happen or when the request to obtain the file system is denied. its argument is the fileerror object. returns void exceptions this method can raise an fileerror with the following code: exception description security_error the application does not have permission to access the file system interface. for example, you cannot run from file://. for more details, see the article on basic concepts. resolvelocalfilesystemurl() lets you look up the entry for a file or directory with a local ur...
...k successcallback, in optional errorcallback errorcallback ); parameters url the url of a local file in the file system. successcallback the success callback that is called when the browser provides the file or directory for the supplied url. errorcallback the error callback that is called when errors happen or when the request to obtain the entry object is denied. returns void exceptions this method can raise an fileerror with the following code: exception description encoding_err the syntax of the url was invalid. not_found_err the url was structurally correct, but refers to a resource that does not exist. security_err the application does not have permission to access the file system interface. browser compatibility ...

MediaRecorder.start() - Web APIs
ent. syntax mediarecorder.start(timeslice) parameters timeslice optional the number of milliseconds to record into each blob. if this parameter isn't included, the entire media duration is recorded into a single blob unless the requestdata() method is called to obtain the blob and trigger the creation of a new blob into which the media continues to be recorded. return value undefined. exceptions errors that can be detected immediately are thrown as dom exceptions. all other errors are reported through error events sent to the mediarecorder object. you can implement the onerror event handler to respond to these errors. invalidmodificationerror the number of tracks on the stream being recorded has changed. you can't add or remove tracks while recording media. invalidstateerror the ...
... can't be recorded using the current configuration. securityerror the mediastream is configured to disallow recording. this may be the case, for example, with sources obtained using getusermedia() when the user denies permission to use an input device. this also happens when a mediastreamtrack within the stream is marked as isolated due to the peeridentity constraint on the source stream. this exception may also be delivered as an error event if the security options for the source media change after recording begins. unknownerror something else went wrong during the recording process. example ... record.onclick = function() { mediarecorder.start(); console.log("recorder started"); } ... specifications specification status comment mediastream recording...

MediaRecorderErrorEvent.error - Web APIs
the read-only error property in the mediarecordererrorevent interface is a domexception object providing details about the exception that was thrown by a mediarecorder instance. when a media​recorder​error​event occurs, you can determine to some extent what went wrong by examining the error property within the media​recorder​error​event received by the mediarecorder's error event handler, onerror. syntax error = mediarecordererrorevent.error; value a domexception describing the error represented by the event. the error's name property's value may be any exception that makes sense during the handling of media recording, including these specifically identified by the specification. the descriptions here are generic ones; you'll find more specific ones to various scenarios in which ...
...thin the stream is marked as isolated due to the peeridentity constraint on the source stream. example this function creates and returns a mediarecorder for a given mediastream, configured to buffer data into an array and to watch for errors. ...

MediaRecorderErrorEvent - Web APIs
read only. constructor mediastreamrecorderevent() creates and returns a new mediarecordererrorevent event object with the given parameters. methods inherits methods from its parent interface, event. ...
...read only. constructor mediastreamrecorderevent() creates and returns a new mediarecordererrorevent event object with the given parameters. methods inherits methods from its parent interface, event. ...

Capabilities, constraints, and settings - Web APIs
individual constraints, as well as an optional sub-object named advanced, which contains another set of zero or more constraints which the user agent must satisfy if at all possible. the user agent attempts to satisfy constraints in the order specified in the constraint set. the most important thing to understand is that most constraints aren't requirements; instead, they're requests. there are exceptions, and we'll get to those shortly. requesting a specific value for a setting most simply, each constraint may be a specific value indicating a desired value for the setting. for example: let constraints = { width: 1920, height: 1080, aspectratio: 1.777777778 }; mytrack.applyconstraints(constraints); in this case, the constraints indicate that any values are fine for nearly all propertie...
... tracks using the code in the two tracks' constraint set edit boxes. function buildconstraints() { try { videoconstraints = json.parse(videoconstrainteditor.value); audioconstraints = json.parse(audioconstrainteditor.value); } catch(error) { handleerror(error); } } this uses json.parse() to parse the code in each editor into an object. if either call to json.parse() throws an exception, handleerror() is called to output the error message to the log. configuring and starting the stream the startvideo() method handles setting up and starting the video stream. function startvideo() { buildconstraints(); navigator.mediadevices.getusermedia({ video: videoconstraints, audio: audioconstraints }).then(function(stream) { let audiotracks = stream.getaudiotracks();...

Navigator.getBattery() - Web APIs
al details, a guide to using the api, and sample code. note: in some browsers access to this feature is controlled by feature-policy directive battery. syntax var batterypromise = navigator.getbattery(); return value a promise which, when resolved, calls its fulfillment handler with a single parameter: a batterymanager object which you can use to get information about the battery's state. exceptions this method doesn't throw true exceptions; instead, it rejects the returned promise, passing into it a domexception whose name is one of the following: securityerror the user agent does not expose battery information to insecure contexts and this method was called from insecure context. note: old versions of some user agents might allow use of this feature in insecure contexts. notallowed...
...for example, it might not be explicitly allowed or restricted via feature-policy battery feature. ...

NodeIterator.detach() - Web APIs
the nodeiterator.detach() method is a no-op, kept for backward compatibility only. originally, it detached the nodeiterator from the set over which it iterates, releasing any resources used by the set and setting the iterator's state to invalid. once this method had been called, calls to other methods on nodeiterator would raise the invalid_state_err exception. ...
...methods on nodeiterator would raise the invalid_state_err exception. syntax nodeiterator.detach(); example var nodeiterator = document.createnodeiterator( document.body, nodefilter.show_element, { acceptnode: function(node) { return nodefilter.filter_accept; } }, false ); nodeiterator.detach(); // detaches the iterator nodeiterator.nextnode(); // throws an invalid_state_err exception specifications specification status comment domthe definition of 'nodeiterator.detach' in that specification. living standard transformed in a no-op document object model (dom) level 2 traversal and range specificationthe definition of 'nodeiterator.detach' in that specification. obsolete initial definition. ...

ParentNode.querySelector() - Web APIs
selectorall() instead. note: this method is implemented as document.queryselector(), documentfragment.queryselector() and element.queryselector(). syntax element = parentnode.queryselector(selectors); parameters selectors a domstring containing one or more selectors to match against. this string must be a valid compound selector list supported by the browser; if it's not, a syntaxerror exception is thrown. see locating dom elements using selectors for more information about using selectors to identify elements. multiple selectors may be specified by separating them using commas. note: characters which are not part of standard css syntax must be escaped using a backslash character. since javascript also uses backspace escaping, special care must be taken when writing string literals us...
...avascript also uses backspace escaping, special care must be taken when writing string literals using these characters. see escaping special characters for more information. return value the first element that matches at least one of the specified selectors or null if no such element is found. note: if the specified selectors include a css pseudo-element, the returned value is always null. exceptions syntaxerror the syntax of the specified selectors string is not valid. specifications specification status comment domthe definition of 'parentnode.queryselector()' in that specification. living standard living standard selectors api level 2the definition of 'parentnode.queryselector()' in that specification. obsolete no change dom...

ParentNode.querySelectorAll() - Web APIs
he queryselector() method instead. note: this method is implemented as element.queryselectorall(), document.queryselectorall(), and documentfragment.queryselectorall() syntax elementlist = parentnode.queryselectorall(selectors); parameters selectors a domstring containing one or more selectors to match against. this string must be a valid css selector string; if it's not, a syntaxerror exception is thrown. see locating dom elements using selectors for more information about using selectors to identify elements. multiple selectors may be specified by separating them using commas. note: characters which are not part of standard css syntax must be escaped using a backslash character. since javascript also uses backslash escaping, special care must be taken when writing string literals us...
...ackslash escaping, special care must be taken when writing string literals using these characters. see escaping special characters for more information. return value a non-live nodelist containing one element object for each descendant node that matches at least one of the specified selectors. note: if the specified selectors include a css pseudo-element, the returned list is always empty. exceptions syntaxerror the syntax of the specified selectors string is not valid. examples to obtain a nodelist of all of the <p> elements in the document: var matches = document.queryselectorall("p"); this example returns a list of all <div> elements within the document with a class of either note or alert: var matches = document.queryselectorall("div.note, div.alert"); here, we get a list of ...

PaymentRequest.show() - Web APIs
ed between instantiating the payment interface and the user beginning to interact with it. the promise should resolve with a paymentdetailsupdate object containing the updated information. return value a promise that eventually resolves with a paymentresponse. the promise is resolved when the user accepts the payment request (such as by clicking a "pay" button in the browser's payment sheet). exceptions aborterror the returned promise rejects with an aborterror if the user agent is already showing a payment panel. only one payment panel may be visible at a time across all documents loaded by the user agent. the promise is also rejected with aborterror if the user cancels the payment request. invalidstateerror the promise rejects with an invalidstateerror if the same payment has alre...
... checkallvalues() looks at each value in the response and ensures that they're valid, returning true if every field is valid or false if any are not. if and only if every field is valid, the complete() method is called on the response with the string "success", which indicates that everything is valid and that the payment can complete accordingly. if any fields have unacceptable values, or if an exception is thrown by the previous code, complete() is called with the string "fail", which indicates that the payment process is complete and failed. instead of immediately failing, you could choose to call retry() on the response object to ask the user agent to try to process the payment again; this should usually only be done after the user has made any needed corrections to the order. starting the p...

Using the Payment Request API - Web APIs
; } }); } else { window.location.href = '/legacy-web-form-checkout'; } } note: see our checking user can make payments before prices are known demo for the full code. recommending a payment app when user has no apps if you select to pay with the bobpay demo payment provider on this merchant page, it tries to call paymentrequest.show(), while intercepting the notsupportederr exception. if this payment method is not supported, it redirects to the signup page for bobpay. the code looks something like this: checkoutbutton.addeventlistener('click', function() { var request = new paymentrequest(buildsupportedpaymentmethoddata(), buildshoppingcartdetails()); request.show().then(function(paymentresponse) { // here we would process the payment. for this demo, simulate ...
...ls()); request.show().then(function(paymentresponse) { // here we would process the payment. for this demo, simulate immediate success: paymentresponse.complete('success') .then(function() { // for demo purposes: intropanel.style.display = 'none'; successpanel.style.display = 'block'; }); }).catch(function(error) { if (error.code == domexception.not_supported_err) { window.location.href = 'https://bobpay.xyz/#download'; } else { // other kinds of errors; cancelled or failed payment. for demo purposes: intropanel.style.display = 'none'; legacypanel.style.display = 'block'; } }); }); note: see our recommending a payment app when user has no apps demo for the full code. showing additional user i...

RTCIceCandidate.RTCIceCandidate() - Web APIs
ct is initialized to the value of the property by the same name from rtcicecandidateinit. this includes the candidate, sdpmid, sdpmlineindex, and usernamefragment properties. the candidate string (which is sdp text) is parsed; each property found is stored in the corresponding field in the rtcicecandidate. if any of the fields is invalid, parsing of the string silently aborts without throwing an exception. the default value of candidate is the empty string, which indicates that the candidate is an "end-of-candidates" message. the following fields are initialized to null if they are not included in the rtcicecandidate.candidate property: foundation, component, priority , ip, protocol, port, type, tcptype, relatedaddress, and relatedport. note: parsing of the candidate string is performed using ...
...ates that the candidate is an "end-of-candidates" message. the following fields are initialized to null if they are not included in the rtcicecandidate.candidate property: foundation, component, priority , ip, protocol, port, type, tcptype, relatedaddress, and relatedport. note: parsing of the candidate string is performed using the candidate-attribute grammar from the webrtc specification. exceptions typeerror the specified rtcicecandidateinit has values of null in both the sdpmid and sdpmlineindex properties. usage notes this constructor does not do complete validation of the specified candidateinfo object or string. specifications specification status comment webrtc 1.0: real-time communication between browsersthe definition of 'rtcicecandidate()' in that s...

RTCIceCandidate.protocol - Web APIs
the protocol property's value is set when the rtcicecandidate() constructor is used. the value is automatically extracted from the candidate a-line, if it's formatted properly. ...
...information about the kind of tcp candidate represented by the object. udp the candidate will use the udp transport protocol for its data. this is the preferred protocol for media interactions because of its better performance profile. note: if protocol is null — and protocol is supported by the user agent — passing the candidate to addicecandidate() will fail, throwing an operationerror exception. usage notes here's an example candidate a-line from an ice transaction: a=candidate:4234997325 1 udp 2043278322 192.168.0.56 44323 typ host the third field, "udp", is the protocol type, indicating that the candidate would use the udp transport protocol. example this code snippet examines the value of protocol to decide if it should look at the value of tcptype to see if it's a simultaneou...

RTCPeerConnection.addIceCandidate() - Web APIs
e() instead. the parameters for this form of addicecandidate() are described below, to aid in updating existing code. successcallback a function to be called when the ice candidate has been successfully added. this function receives no input parameters and doesn't return a value. failurecallback a function to be called if attempting to add the ice candidate fails. ...
...ut parameters and doesn't return a value. failurecallback a function to be called if attempting to add the ice candidate fails. receives as input a domexception object describing why failure occurred. return value a promise which is fulfilled when the candidate has been successfully added to the remote peer's description by the ice agent. the promise does not receive any input parameters. exceptions when an error occurs while attempting to add the ice candidate, the promise returned by this method is rejected, returning one of the errors below as the name attribute in the specified domexception object passed to the rejection handler. typeerror the specified candidate's sdpmid and sdpmlineindex are both null. invalidstateerror the rtcpeerconnection currently has no remote peer establi...

RTCPeerConnection.createOffer() - Web APIs
ode to use the promise-based version of createoffer() instead. the parameters for this form of createoffer() are described below, to aid in updating existing code. successcallback an rtcsessiondescriptioncallback which will be passed a single rtcsessiondescription object describing the newly-created offer. errorcallback an rtcpeerconnectionerrorcallback which will be passed a single domexception object explaining why the request to create an offer failed. options optional an optional rtcofferoptions dictionary providing options requested for the offer. return value a promise whose fulfillment handler will receive an object conforming to the rtcsessiondescriptioninit dictionary which contains the sdp describing the generated offer. that received offer should be delivered through the ...
...o create an offer failed. options optional an optional rtcofferoptions dictionary providing options requested for the offer. return value a promise whose fulfillment handler will receive an object conforming to the rtcsessiondescriptioninit dictionary which contains the sdp describing the generated offer. that received offer should be delivered through the signaling server to a remote peer. exceptions these exceptions are returned by rejecting the returned promise. your rejection handler should examine the received exception to determine which occurred. invalidstateerror the rtcpeerconnection is closed. notreadableerror no certificate or set of certificates was provided for securing the connection, and createoffer() was unable to create a new one. since all webrtc connections are requi...

RTCPeerConnection.getStats() - Web APIs
ts(selector) parameters selector optional a mediastreamtrack for which to gather statistics. if this is null (the default value), statistics will be gathered for the entire rtcpeerconnection. return value a promise which resolves with an rtcstatsreport object providing connection statistics. the contents of the report depend on the selector as well as other details of the connection. exceptions this method does not throw exceptions; instead, it rejects the returned promise with one of the following errors: invalidaccesserror there is no rtcrtpsender or rtcrtpreceiver whose track matches the specified selector, or selector matches more than one sender or receiver. obsolete syntax previously, getstats() used success and failure callbacks to report the results to you, instead of u...
... gathered for the entire rtcpeerconnection. successcallback a callback function to call when the stats have been retrieved. the function receives as input a single parameter: an rtcstatsreport with the collected statistics. no output is expected from the function. failurecallback a function to call when an error occurs while attempting to collect statistics. the callback receives as input the exception (a domexception object describing the error which occurred. no return value is expected from the callback. example this example creates a periodic function using setinterval() that collects statistics for an rtcpeerconnection every second, generating an html-formatted report and inserting it into a specific element in the dom. window.setinterval(function() { mypeerconnection.getstats(null).

RTCPeerConnection.setLocalDescription() - Web APIs
ting existing code. successcallback a javascript function which accepts no input parameters to be be called once the description has been successfully set. at that time, the offer can be sent to a remote peer via the signaling server. errorcallback a function matching the signature rtcpeerconnectionerrorcallback which gets called if the description can't be set. ...
...nature rtcpeerconnectionerrorcallback which gets called if the description can't be set. it is passed a single domexception object explaining why the request failed. this deprecated form of the method returns instantaneously without waiting for the actual setting to be done: in case of success, the successcallback will be called; in case of failure, the errorcallback will be called. deprecated exceptions when using the deprecated callback-based version of setlocaldescription(), the following exceptions may occur: invalidstateerror the connection's signalingstate is "closed", indicating that the connection is not currently open, so negotiation cannot take place. invalidsessiondescriptionerror the rtcsessiondescription specified by the sessiondescription parameter is invalid. examples...

RTCRtpTransceiver.setCodecPreferences() - Web APIs
, in order of preference, each providing the parameters for one of the transceiver's supported codecs. if codecs is empty, the codec configurations are all returned to the user agent's defaults. note: any codecs not included in codecs will not be considered during the process of negotiating a connection. this lets you prevent the use of codecs you don't wish to use. return value undefined exceptions invalidaccesserror the codecs list includes one or more codecs which are not supported by the transceiver. usage notes getting a list of supported codecs you can only include in the codecs list codecs which the transceiver actually supports. that means that either the associated rtcrtpsender or the rtcrtpreceiver needs to support every codec in the list. if any unsupported codecs are lis...
...one or more codecs which are not supported by the transceiver. usage notes getting a list of supported codecs you can only include in the codecs list codecs which the transceiver actually supports. that means that either the associated rtcrtpsender or the rtcrtpreceiver needs to support every codec in the list. if any unsupported codecs are listed, the browser will throw an invalidaccesserror exception when you call this method. a good approach to setting codec preferences is to first get the list of codecs that are actually supported, then modify that list to match what you want. pass the altered list into setcodecpreferences() to specify your preferences. to determine which codecs are supported by the transceiver, call the sender's getcapabilities() and the receiver's getcapabilities() meth...

SVGAnimationElement - Web APIs
cause the href specifies an unknown element) the value returned is null. methods this interface also inherits methods from its parent, svgelement. svganimationelement.getstarttime() returns a float representing the begin time, in seconds, for this animation element's current interval, if it exists, regardless of whether the interval has begun yet. if there is no current interval, then a domexception with code invalid_state_err is thrown. svganimationelement.getcurrenttime() returns a float representing the current time in seconds relative to time zero for the given time container. svganimationelement.getsimpleduration() returns a float representing the number of seconds for the simple duration for this animation. if the simple duration is undefined (e.g., the end time is indefinite), the...
...ode invalid_state_err is thrown. svganimationelement.getcurrenttime() returns a float representing the current time in seconds relative to time zero for the given time container. svganimationelement.getsimpleduration() returns a float representing the number of seconds for the simple duration for this animation. if the simple duration is undefined (e.g., the end time is indefinite), then a domexception with code not_supported_err is raised. svganimationelement.beginelement() creates a begin instance time for the current time. the new instance time is added to the begin instance times list. the behavior of this method is equivalent to beginelementat(0). svganimationelement.beginelementat() creates a begin instance time for the current time plus the specified offset. the new instance ti...

SVGMatrix - Web APIs
warning: svg 2 replaced the svgmatrix interface by the more general dommatrix and dommatrixreadonly interfaces. ...
...ing matrix as svgmatrix. svgmatrix.flipy() post-multiplies the transformation [1 0 0 -1 0 0] and returns the resulting matrix as svgmatrix. svgmatrix.skewx() post-multiplies a skewx transformation on the current matrix and returns the resulting matrix as svgmatrix. svgmatrix.skewy() post-multiplies a skewy transformation on the current matrix and returns the resulting matrix as svgmatrix. exceptions a domexception with the code no_modification_allowed_err is raised when attempting updating a read-only attribute or when the object itself is read-only. specifications specification status comment scalable vector graphics (svg) 1.1 (second edition)the definition of 'svgmatrix' in that specification. recommendation initial definition ...

SVGNumber - Web APIs
methods this interface doesn't provide any specific methods. ...
... methods this interface doesn't provide any specific methods. ...

SVGPreserveAspectRatio - Web APIs
svg preserveaspectratio interface the svgpreserveaspectratio interface corresponds to the preserveaspectratio attribute, which is available for some of svg's elements. an svgpreserveaspectratio object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown. interface overview also implement none methods none properties unsigned short align unsigned short meetorslice constants svg_preserveaspectratio_unknown = 0 svg_preserveaspectratio_none = 1 svg_preserveaspectratio_xminymin = 2 svg_preserveaspectratio_xmidymin = 3 svg_preserveaspectratio_xmaxymin = 4 svg_preserveaspectratio_xminymid = 5 svg_preserveaspectratio_xmidym...
...veaspectratio. properties name type description align unsigned short the type of the alignment value as specified by one of the svg_preserveaspectratio_* constants defined on this interface. meetorslice unsigned short the type of the meet-or-slice value as specified by one of the svg_meetorslice_* constants defined on this interface. exceptions on setting: a domexception with code no_modification_allowed_err is raised on an attempt to change the value of an attribute on a read only object. methods the svgpreserveaspectratio interface do not provide any specific methods. browser compatibility the compatibility table on this page is generated from structured data. if you'd like to contribute to the data, please check out https://gith...

SVGStyleElement - Web APIs
-anchor="middle" alignment-baseline="middle">svgstyleelement</text></a></svg></div> a:hover text { fill: #0095dd; pointer-events: all;} properties this interface also inherits properties from its parent interface, svgelement and implements properties from linkstyle. svgstyleelement.type a domstring corresponding to the type attribute of the given element. svg 1.1 defined that a domexception is raised with code no_modification_allowed_err on an attempt to change the value of a read-only attribute. this restriction was removed in svg 2. svgstyleelement.media a domstring corresponding to the media attribute of the given element. svg 1.1 defined that a domexception is raised with code no_modification_allowed_err on an attempt to change the value of a read-only attribute. this restr...
...this restriction was removed in svg 2. ...

SourceBuffer.abort() - Web APIs
example the spec description of abort() is somewhat confusing — consider for example step 1 of reset parser state. ...
... example the spec description of abort() is somewhat confusing — consider for example step 1 of reset parser state. ...

SourceBuffer.mode - Web APIs
utomatically for the segments that observe this order. the mode value is initially set when the sourcebuffer is created using mediasource.addsourcebuffer(). if timestamps already exist for the media segments, then the value will be set to segments; if they don't, then the value will be set to sequence. if you try to set the mode property value to segments when the initial value is sequence, an exception will be thrown. the existing segment order must be maintained in sequence mode. you can, however, change the value from segments to sequence. it just means the play order will be fixed, and new timestamps generated to reflect this. this property cannot be changed during while the sourcebuffer is processing either an appendbuffer() or remove() call. syntax var mymode = sourcebuffer.mode; sourc...
...e maintained in sequence mode. you can, however, change the value from segments to sequence. it just means the play order will be fixed, and new timestamps generated to reflect this. this property cannot be changed during while the sourcebuffer is processing either an appendbuffer() or remove() call. syntax var mymode = sourcebuffer.mode; sourcebuffer.mode = 'sequence'; value a domstring. exceptions the following exceptions may be thrown when setting a new value for this property. exception explanation invalidaccesserror an attempt was made to set the value to segments when the initial value is sequence. invalidstateerror the sourcebuffer object is being updated (i.e. its sourcebuffer.updating property is currently true), the last media segment appe...

Storage Access API - Web APIs
ak embedded cross-origin content that requires access to its first-party storage. as an example, federated logins often require access to authentication cookies stored in first-party storage, and will require the user to sign in on each site separately (or completely break) if those cookies are not available. in the case of breakage, site owners have often encouraged users to add their site as an exception or to disable the policy entirely. as a consequence, users who wish to continue to interact with embedded content are forced to greatly relax their blocking policy for resources loaded from all embedded origins and possibly across all websites. the storage access api is intended to solve this problem; embedded cross-origin content can request unrestricted access to its first-party storage on a s...
...ding website needs to add this to allow storage access requests to be successful, along with allow-scripts and allow-same-origin to allow it to call the api, and execute in an origin that can have cookies: <iframe sandbox="allow-storage-access-by-user-activation allow-scripts allow-same-origin"> ... </iframe> the api is designed to limit the potential storage exceptions to origins for which the user has shown an intent to interact. this is enforced through the following constraints: access requests are automatically denied unless the embedded content is currently processing a user gesture such as a tap or click. this also prevents embedded content on the page from spamming the browser or user with excessive access requests. origins that have never been inte...

WakeLockSentinel.release() - Web APIs
you should always listen for the onrelease event to check if a wake lock has been released. ...
...you should always listen for the onrelease event to check if a wake lock has been released. ...

Lighting a WebXR setting - Web APIs
le some of these are also useful in any other 3d setting, most are specific to virtual reality and, in some cases even more so, to augmented reality. since your scene is intended to represent a setting a person or their avatar can exist within, you should try to achieve some degree of consistency and realism in terms of the positioning and presentation of your light sources. obviously, there are exceptions to this guideline, such as when your scene represents an otherworldly or alien setting, or when your goal is to create an unsettling visual effect. realism in light source placement when possible, you should try to make your virtual light sources correspond to objects that actually exists. if you have a virtual room that needs overhead lighting, have a model of a ceiling lamp at the location o...
...en your scene represents an otherworldly or alien setting, or when your goal is to create an unsettling visual effect. realism in light source placement when possible, you should try to make your virtual light sources correspond to objects that actually exists. if you have a virtual room that needs overhead lighting, have a model of a ceiling lamp at the location of your light source. there are exceptions, such as the ambient lighting that simply adds a baseline amount of lighting to your setting, and the sun, which is a directional light (that is, a light source where every light ray is parallel, coming from somewhere in the sky and ending somewhere within your scene). try to place light sources in realistic locations for the setting and the mood you're trying to create. a scene intended to fee...

Using the Web Storage API - Web APIs
ability note: this api is available in current versions of all major browsers. testing for availability is necessary only if you must support very old browsers, such as internet explorer 6 or 7, or in the limited circumstances described below. browsers that support localstorage have a property on the window object named localstorage. however, just asserting that that property exists may throw exceptions. if the localstorage object does exist, there is still no guarantee that the localstorage api is actually available, as various browsers offer settings that disable localstorage. so a browser may support localstorage, but not make it available to the scripts on the page. for example, safari browser in private browsing mode gives us an empty localstorage object with a quota of zero, effectively ...
...ction should take these scenarios into account. ...

Web Workers API - Web APIs
global context that is different from the current window. this context is represented by either a dedicatedworkerglobalscope object (in the case of dedicated workers - workers that are utilized by a single script), or a sharedworkerglobalscope (in the case of shared workers - workers that are shared between multiple scripts). you can run whatever code you like inside the worker thread, with some exceptions. for example, you can't directly manipulate the dom from inside a worker, or use some default methods and properties of the window object. but you can use a large number of items available under window, including websockets, and data storage mechanisms like indexeddb. see functions and classes available to workers for more details. data is sent between workers and the main thread via a system ...
...heir messages using the postmessage() method, and respond to messages via the onmessage event handler (the message is contained within the message event's data property). the data is copied rather than shared. workers may in turn spawn new workers, as long as those workers are hosted within the same origin as the parent page. in addition, workers may use xmlhttprequest for network i/o, with the exception that the responsexml and channel attributes on xmlhttprequest always return null. in addition to dedicated workers, there are other types of worker: shared workers are workers that can be utilized by multiple scripts running in different windows, iframes, etc., as long as they are in the same domain as the worker. they are a little more complex than dedicated workers — scripts must communic...

How to check the security state of an XMLHTTPRequest over SSL - Web APIs
can only call it from a browser extension or from a xulrunner application. the channel property becomes available only after the request is sent and the connection was established, that is, on readystate loaded, interactive or completed. by setting the mozbackgroundrequest property of the request object and modifying the example appropriately, you can create your own alert dialog to handle ssl exceptions in your firefox extension or xulrunner application. // adapted from the patch for moztcpsocket error reporting (bug 861196). const {cc,ci} = require("chrome"); function createtcperrorfromfailedxhr(xhr) { let status = xhr.channel.queryinterface(ci.nsirequest).status; let errtype; if ((status & 0xff0000) === 0x5a0000) { // security module const nsinsserrorsservice = ci.nsinsserrorsse...
... = ci.nsinsserrorsservice; let nsserrorsservice = cc['@mozilla.org/nss_errors_service;1'].getservice(nsinsserrorsservice); let errorclass; // geterrorclass will throw a generic ns_error_failure if the error code is // somehow not in the set of covered errors. ...

XMLSerializer.serializeToString() - Web APIs
the xmlserializer method serializetostring() constructs a string representing the specified dom tree in xml form. syntax xmlstring = anxmlserializer.serializetostring(rootnode); parameters rootnode the node to use as the root of the dom tree or subtree for which to construct an xml representation. return value a domstring containing the xml representation of the specified dom tree. exceptions typeerror the specified rootnode is not a compatible node type. the root node must be either node or attr. invalidstateerror the tree could not be successfully serialized, probably due to issues with the content's compatibility with xml serialization. syntaxerror a serialization of html was requested but could not succeed due to the content not being well-formed. usage notes compatible n...
...node—and all of its descendants—must be compatible with the xml serialization algorithm. the root node itself must be either a node or attr object. the following types are also permitted as descendants of the root node, in addition to node and attr: documenttype document documentfragment element comment text processinginstruction attr if any other type is encountered, a typeerror exception is thrown. notes on the resulting xml there are some things worth noting about the xml output by serializetostring(): for xml serializations, element and attr nodes are always serialized with their namespaceuri intact. this may mean that a previously-specified prefix or default namespace may be dropped or altered. the resulting xml is compatible with the html parser. elements in the html n...

XRSystem: isSessionSupported() - Web APIs
the xrsystem method issessionsupported() returns a promise which resolves to true if the specified webxr session mode is supported by the user's webxr device. otherwise, the promise resolves with false. if the no devices are available or the browser doesn't have permission to use the xr device, the promise is rejected with an appropriate domexception. syntax var issupportedpromise = xr.issessionsupported(xrsessionmode) parameters xrsessionmode a domstring specifying the webxr session mode for which support is to be checked. this string must be one of inline (to present the webxr content inline within the context of an html document) or immersive-vr for a fully-immersive virtual experience. return value a promise that resolves to true if the specified session mode is supported; otherwise...
...xrsessionmode a domstring specifying the webxr session mode for which support is to be checked. this string must be one of inline (to present the webxr content inline within the context of an html document) or immersive-vr for a fully-immersive virtual experience. return value a promise that resolves to true if the specified session mode is supported; otherwise the promise resolves to false. exceptions rather than throwing true exceptions, issessionsupported() rejects the returned promise, passing to the rejection handler a domexception whose name is one of the following strings. securityerror the document's origin does not have permission to use the xr-spatial-tracking feature policy. examples in this example, we see issessionsupported() used to detect whether or not the device suppor...

Cognitive accessibility - Accessibility
ity, and information and functionality cannot be achieved in another way that would conform. this includes animated gifs, if the gif animates for more than 5 seconds. additional timing criteria to consider are: people who have cognitive or language limitations may need more time to read and to understand. for improved usability remove any time limit. timed content should also be avoided, with exceptions for non-interactive synchronized media and real-time events. people with attention deficit disorders should be able to focus on content without distractions. the user should be able to postpone or suppress interruptions, except situations involving altering a person to an emergency. this provides access to people with cognitive disabilities by enabling them to focus on the main purpose of the c...
... for example, saving the state of a questionnaire. make sure to save data in such a way that it can be modified after a user re-authenticates. before re-authenticating, encode the data as hidden or encrypted. providing warnings about inactivity that could result in data loss. when a timeout is used, tell people exactly how much time will cause the session to time out and result in lost data. the exception to this is preserving data for more than 20 hours when no actions are taken. navigation guideline 2.4 states "provide ways to help users navigate, find content, and determine where they are," and provides 10 guidelines to ensure the site is navigable and content is findable: include a <title> make sure to include a <title> for the document, as titles provide a quick and easy to refere...

Getting Started - Developer guides
ent get parameter, like a timestamp or random number (see bypassing the cache) note 3: if the httprequest variable is used globally, competing functions calling makerequest() can overwrite each other, causing a race condition. declaring the httprequest variable local to a closure containing the ajax functions avoids this. in the event of a communication error (such as the server going down), an exception will be thrown in the onreadystatechange method when accessing the response status. to mitigate this problem, you could wrap your if...then statement in a try...catch: function alertcontents() { try { if (httprequest.readystate === xmlhttprequest.done) { if (httprequest.status === 200) { alert(httprequest.responsetext); } else { alert('there was a problem with t...
...e response status. to mitigate this problem, you could wrap your if...then statement in a try...catch: function alertcontents() { try { if (httprequest.readystate === xmlhttprequest.done) { if (httprequest.status === 200) { alert(httprequest.responsetext); } else { alert('there was a problem with the request.'); } } } catch( e ) { alert('caught exception: ' + e.description); } } step 4 – working with the xml response in the previous example, after receiving the response to the http request we used the request object's responsetext property , which contained the contents of the test.html file. now let's try the responsexml property. first off, let's create a valid xml document that we'll request later on. the document (test.xml) contains t...

<input>: The Input (Form Input) element - HTML: Hypertext Markup Language
is step is not included. step="any" will never throw this error. type validitystate.typemismatch occurs when the value is not of the correct type, for example a email does not contain an @ or a url doesn't contain a protocol. if a form control doesn't have the required attribute, no value, or an empty string, is not invalid. even if the above attributes are present, with the exception of required, and empty string will not lead to an error. we can set limits on what values we accept, and supporting browsers will natively validate these form values and alert the user if there is a mistake when the form is submitted. in addition to the errors described in the table above, the validitystate interface contains the badinput, valid, and customerror boolean readonly properties. the...
... if there is an error, supporting browsers will both alert the user and prevent the form from being submitted. a word of caution: if a custom error is set to a truthy value (anything other than the empty string or null), the form will be be prevented from being submitted. if there is no custom error message, and no...

MIME types (IANA media types) - HTTP
main type is text, the optional charset parameter can be used to specify the character set used for the characters in the data. if no charset is specified, the default is ascii (us-ascii) unless overridden by the user agent's settings. to specify a utf-8 text file, the mime type text/plain;charset=utf-8 is used. mime types are case-insensitive but are traditionally written in lowercase, with the exception of parameter values, whose case may or may not have specific meaning. types there are two classes of type: discrete and multipart. discrete types are types which represent a single file or medium, such as a single text or music file, or a single video. a multipart type is one which represents a document that's comprised of multiple component parts, each of which may have its own individual mime...
...ary documents without a specific or known subtype, application/octet-stream should be used. multipart types multipart types indicate a category of document broken into pieces, often with different mime types; they can also be used — especially in email scenarios — to represent multiple, separate files which are all part of the same transaction. they represent a composite document. with the exception of multipart/form-data, used in the post method of html forms, and multipart/byteranges, used with 206 partial content to send part of a document, http doesn't handle multipart documents in a special way: the message is transmitted to the browser (which will likely show a "save as" window if it doesn't know how to display the document). there are two multipart types: message list at iana a m...

Content-Security-Policy - HTTP
this helps guard against cross-site scripting attacks (xss). for more information, see the introductory article on content security policy (csp). header type response header forbidden header name no syntax content-security-policy: <policy-directive>; <policy-directive> where <policy-directive> consists of: <directive> <value> with no internal punctuation. ...
...ve is intended for web sites with large numbers of insecure legacy urls that need to be rewritten. csp in workers workers are in general not governed by the content security policy of the document (or parent worker) that created them. to specify a content security policy for the worker, set a content-security-policy response header for the request which requested the worker script itself. the exception to this is if the worker script's origin is a globally unique identifier (for example, if its url has a scheme of data or blob). in this case, the worker does inherit the content security policy of the document or worker that created it. multiple content security policies the csp mechanism allows multiple policies being specified for a resource, including via the content-security-policy header,...

HTTP response status codes - HTTP
n of a proxy. 306 unused this response code is no longer used; it is just reserved. it was used in a previous version of the http/1.1 specification. 307 temporary redirect the server sends this response to direct the client to get the requested resource at another uri with same method that was used in the prior request. ...
... client error responses 400 bad request the server could not understand the request due to invalid syntax. 401 unauthorized although the http standard specifies "unauthorized", semantically this response means "unauthenticated". ...

Equality comparisons and sameness - JavaScript
an attempt is made to mutate an immutable property: // add an immutable negative_zero property to the number constructor. object.defineproperty(number, 'negative_zero', { value: -0, writable: false, configurable: false, enumerable: false }); function attemptmutation(v) { object.defineproperty(number, 'negative_zero', { value: v }); } object.defineproperty will throw an exception when attempting to change an immutable property, but it does nothing if no actual change is requested. if v is -0, no change has been requested, and no error will be thrown. internally, when an immutable property is redefined, the newly-specified value is compared against the current value using same-value equality. same-value equality is provided by the object.is method. same-value-zero equali...
...nd readable. hint: read the strict equality algorithm first.) es5 also describes, in section 9.12, the samevalue algorithm for use internally by the js engine. it's largely the same as the strict equality algorithm, except that 11.9.6.4 and 9.12.4 differ in handling numbers. es2015 simply proposes to expose this algorithm through object.is. we can see that with double and triple equals, with the exception of doing a type check upfront in 11.9.6.1, the strict equality algorithm is a subset of the abstract equality algorithm, because 11.9.6.2–7 correspond to 11.9.3.1.a–f. a model for understanding equality comparisons? prior to es2015, you might have said of double equals and triple equals that one is an "enhanced" version of the other. for example, someone might say that double equals is an e...

Expressions and operators - JavaScript
er the comparison is true. the operands can be numerical, string, logical, or object values. strings are compared based on standard lexicographical ordering, using unicode values. in most cases, if the two operands are not of the same type, javascript attempts to convert them to an appropriate type for the comparison. this behavior generally results in comparing the operands numerically. the sole exceptions to type conversion within comparisons involve the === and !== operators, which perform strict equality and inequality comparisons. these operators do not attempt to convert the operands to compatible types before checking equality. the following table describes the comparison operators in terms of this sample code: var var1 = 3; var var2 = 4; comparison operators operator descrip...
...returns true instanceof the instanceof operator returns true if the specified object is of the specified object type. the syntax is: objectname instanceof objecttype where objectname is the name of the object to compare to objecttype, and objecttype is an object type, such as date or array. use instanceof when you need to confirm the type of an object at runtime. for example, when catching exceptions, you can branch to different exception-handling code depending on the type of exception thrown. for example, the following code uses instanceof to determine whether theday is a date object. because theday is a date object, the statements in the if statement execute. var theday = new date(1995, 12, 17); if (theday instanceof date) { // statements to execute } operator precedence the preced...

Grammar and types - JavaScript
global variable. it also generates a strict javascript warning. undeclared global variables can often lead to unexpected behavior. thus, it is discouraged to use undeclared global variables. evaluating variables a variable declared using the var or let statement with no assigned value specified has the value of undefined. ...
...e immediate if statement block. if (true) { var x = 5; } console.log(x); // x is 5 this behavior changes when using the let declaration (introduced in ecmascript 2015). if (true) { let y = 5; } console.log(y); // referenceerror: y is not defined variable hoisting another unusual thing about variables in javascript is that you can refer to a variable declared later, without getting an exception. this concept is known as hoisting. variables in javascript are, in a sense, "hoisted" (or "lifted") to the top of the function or statement. however, variables that are hoisted return a value of undefined. so even if you declare and initialize after you use or refer to this variable, it still returns undefined. /** * example 1 */ console.log(x === undefined); // true var x = 3; /** * examp...

Using Promises - JavaScript
error caused a rejection. error propagation you might recall seeing failurecallback three times in the pyramid of doom earlier, compared to only once at the end of the promise chain: dosomething() .then(result => dosomethingelse(result)) .then(newresult => dothirdthing(newresult)) .then(finalresult => console.log(`got the final result: ${finalresult}`)) .catch(failurecallback); if there's an exception, the browser will look down the chain for .catch() handlers or onrejected. this is very much modeled after how synchronous code works: try { const result = syncdosomething(); const newresult = syncdosomethingelse(result); const finalresult = syncdothirdthing(newresult); console.log(`got the final result: ${finalresult}`); } catch(error) { failurecallback(error); } this symmetry with ...
...se(result); const finalresult = await dothirdthing(newresult); console.log(`got the final result: ${finalresult}`); } catch(error) { failurecallback(error); } } it builds on promises, e.g. dosomething() is the same function as before. you can read more about the syntax here. promises solve a fundamental flaw with the callback pyramid of doom, by catching all errors, even thrown exceptions and programming errors. this is essential for functional composition of asynchronous operations. promise rejection events whenever a promise is rejected, one of two events is sent to the global scope (generally, this is either the window or, if being used in a web worker, it's the worker or other worker-based interface). the two events are: rejectionhandled sent when a promise is rejected,...

TypeError: can't access dead object - JavaScript
message typeerror: can't access dead object error type typeerror what went wrong? to improve in memory usage and to prevent memory leaks, firefox disallows add-ons to keep strong references to dom objects after their parent document has been destroyed. a dead object, is holding a strong (keep alive) reference to a dom element that persists even after it was destroyed in the dom. ...
... try { string(window); } catch (e) { console.log("window is likely dead"); } ...

TypeError: "x" is not a constructor - JavaScript
message typeerror: object doesn't support this action (edge) typeerror: "x" is not a constructor typeerror: math is not a constructor typeerror: json is not a constructor typeerror: symbol is not a constructor typeerror: reflect is not a constructor typeerror: intl is not a constructor typeerror: atomics is not a constructor error type typeerror what went wrong? there was an attempt to use an object or a variable as a constructor, but that object or variable is not a constructor. see constructor or the new operator for more information on what a constructor is. ...
...his.year = year; } now you can create an object called mycar as follows: var mycar = new car('eagle', 'talon tsi', 1993); in promises when returning an immediately-resolved or immediately-rejected promise, you do not need to create a new promise(...) and act on it. ...

Function.prototype.apply() - JavaScript
y kind of object which is array-like. in practice, this means it's going to have a length property, and integer ("index") properties in the range (0..length - 1). for example, you could use a nodelist, or a custom object like { 'length': 2, '0': 'eat', '1': 'bananas' }. note: many older browsers—including chrome <17 and internet explorer <9—don't accept array-like objects, and will throw an exception. examples using apply to append an array to another you can use push to append an element to an array. and, because push accepts a variable number of arguments, you can also push multiple elements at once. but, if you pass an array to push, it will actually add that array as a single element, instead of adding the elements individually. so you end up with an array inside an array. what if t...
...eeding the javascript engine's argument length limit. the consequences of applying a function with too many arguments (that is, more than tens of thousands of arguments) varies across engines. (the javascriptcore engine has hard-coded argument limit of 65536. this is because the limit (and indeed, even the nature of any excessively-large-stack behavior) is unspecified. some engines will throw an exception. more perniciously, others will arbitrarily limit the number of arguments actually passed to the applied function. to illustrate this latter case: if such an engine had a limit of four arguments (actual limits are of course significantly higher), it would be as if the arguments 5, 6, 2, 3 had been passed to apply in the examples above, rather than the full array. if your value array might grow i...

Object.assign() - JavaScript
ole.log(copy); // { baz: 3 } primitives will be wrapped to objects const v1 = 'abc'; const v2 = true; const v3 = 10; const v4 = symbol('foo'); const obj = object.assign({}, v1, null, v2, undefined, v3, v4); // primitives will be wrapped, null and undefined will be ignored. // note, only string wrappers can have own enumerable properties. ...
...string wrappers can have own enumerable properties. console.log(obj); // { "0": "a", "1": "b", "2": "c" } exceptions will interrupt the ongoing copying task const target = object.defineproperty({}, 'foo', { value: 1, writable: false }); // target.foo is a read-only property object.assign(target, { bar: 2 }, { foo2: 3, foo: 3, foo3: 3 }, { baz: 4 }); // typeerror: "foo" is read-only // the exception is thrown when assigning target.foo console.log(target.bar); // 2, the first source was copied successfully. console.log(target.foo2); // 3, the first property of the second source was copied successfully. console.log(target.foo); // 1, exception is thrown here. console.log(target.foo3); // undefined, assign method has finished, foo3 will not be copied. console.log(target.baz); // undefined, ...

Object.prototype.constructor - JavaScript
the constructor property returns a reference to the object constructor function that created the instance object. note that the value of this property is a reference to the function itself, not a string containing the function's name. the value is only read-only for primitive values such as 1, true, and "test". description all objects (with the exception of objects created with object.create(null)) will have a constructor property. objects created without the explicit use of a constructor function (such as object- and array-literals) will have a constructor property that points to the fundamental object constructor type for that object. let o = {} o.constructor === object // true let o = new object o.constructor === object // true let a = [] a.constructor === array // true let a = new array...
...create itself. function parent() { /* ... */ } function createdconstructor() { parent.call(this) } createdconstructor.prototype = object.create(parent.prototype) createdconstructor.prototype.create = function create() { return new this.constructor() } new createdconstructor().create().create() // typeerror undefined is not a function since constructor === parent in the example above the exception will be shown since the constructor links to parent. to avoid this, just assign the necessary constructor you are going to use. function parent() { /* ... */ } function createdconstructor() { /* ... */ } createdconstructor.prototype = object.create(parent.prototype) createdconstructor.prototype.constructor = createdconstructor // sets the correct constructor for future use createdconstructor.

handler.setPrototypeOf() - JavaScript
totypeof() reflect.setprototypeof() invariants if the following invariants are violated, the proxy will throw a typeerror: if target is not extensible, the prototype parameter must be the same value as object.getprototypeof(target). examples if you want to disallow setting a new prototype for your object, your handler's setprototypeof() method can either return false, or it can throw an exception. approach 1: returning false this approach means that any mutating operation that throws an exception on failure to mutate, must create the exception itself. for example, object.setprototypeof() will create and throw a typeerror itself. if the mutation is performed by an operation that doesn't ordinarily throw in case of failure, such as reflect.setprototypeof(), no exception will be thrown. ...
...failure, such as reflect.setprototypeof(), no exception will be thrown. const handlerreturnsfalse = { setprototypeof(target, newproto) { return false; } }; const newproto = {}, target = {}; const p1 = new proxy(target, handlerreturnsfalse); object.setprototypeof(p1, newproto); // throws a typeerror reflect.setprototypeof(p1, newproto); // returns false approach 2: throwing an exception the latter approach will cause any operation that attempts to mutate, to throw. this approach is best if you want even non-throwing operations to throw on failure, or you want to throw a custom exception value. const handlerthrows = { setprototypeof(target, newproto) { throw new error('custom error'); } }; const newproto = {}, target = {}; const p2 = new proxy(target, handler...

Proxy - JavaScript
this example uses the construct and apply handlers. function extend(sup, base) { var descriptor = object.getownpropertydescriptor( base.prototype, 'constructor' ); base.prototype = object.create(sup.prototype); var handler = { constru...
...this example uses the construct and apply handlers. function extend(sup, base) { var descriptor = object.getownpropertydescriptor( base.prototype, 'constructor' ); base.prototype = object.create(sup.prototype); var handler = { construct: function(target, args) { var obj = obj...

RangeError() constructor - JavaScript
the rangeerror() constructor creates an error when a value is not in the set or range of allowed values. syntax new rangeerror([message[, filename[, linenumber]]]) parameters message optional human-readable description of the error. ...
... the rangeerror() constructor creates an error when a value is not in the set or range of allowed values. syntax new rangeerror([message[, filename[, linenumber]]]) parameters message optional human-readable description of the error. ...

SyntaxError() constructor - JavaScript
the syntaxerror constructor creates a new error object that represents an error when trying to interpret syntactically invalid code. ...
...ctor creates a new error object that represents an error when trying to interpret syntactically invalid code. ...

TypeError() constructor - JavaScript
the typeerror() constructor creates a new error when an operation could not be performed, typically (but not exclusively) when a value is not of the expected type. syntax new typeerror([message[, filename[, linenumber]]]) parameters message optional optional. human-readable description of the error filename optional optional. ...
...erformed, typically (but not exclusively) when a value is not of the expected type. syntax new typeerror([message[, filename[, linenumber]]]) parameters message optional optional. human-readable description of the error filename optional optional. the name of the file containing the code that caused the exception linenumber optional optional. ...

TypedArray.prototype.set() - JavaScript
lease clone https://github.com/mdn/interactive-examples and send us a pull request. syntax typedarray.set(array[, offset]) typedarray.set(typedarray[, offset]) parameters array the array from which to copy values. all values from the source array are copied into the target array, unless the length of the source array plus the offset exceeds the length of the target array, in which case an exception is thrown. typedarray if the source array is a typed array, the two arrays may share the same underlying arraybuffer; the javascript engine will intelligently copy the source range of the buffer to the destination range. offset optional the offset into the target array at which to begin writing values from the source array. if this value is omitted, 0 is assumed (that is, the source array wil...
...the two arrays may share the same underlying arraybuffer; the javascript engine will intelligently copy the source range of the buffer to the destination range. offset optional the offset into the target array at which to begin writing values from the source array. if this value is omitted, 0 is assumed (that is, the source array will overwrite values in the target array starting at index 0). exceptions a rangeerror, if the offset is set such as it would store beyond the end of the typed array. examples using set() var buffer = new arraybuffer(8); var uint8 = new uint8array(buffer); uint8.set([1, 2, 3], 3); console.log(uint8); // uint8array [ 0, 0, 0, 1, 2, 3, 0, 0 ] specifications specification ecmascript (ecma-262)the definition of 'typedarray.prototype.set' in ...

WebAssembly.instantiate() - JavaScript
e or else a webassembly.linkerror is thrown. return value a promise that resolves to a resultobject which contains two fields: module: a webassembly.module object representing the compiled webassembly module. this module can be instantiated again, shared via postmessage() or cached in indexeddb. instance: a webassembly.instance object that contains all the exported webassembly functions. exceptions if either of the parameters are not of the correct type or structure, a typeerror is thrown. if the operation fails, the promise rejects with a webassembly.compileerror, webassembly.linkerror, or webassembly.runtimeerror, depending on the cause of the failure. secondary overload — taking a module object instance promise<webassembly.instance> webassembly.instantiate(module, importobject)...
...odule the webassembly.module object to be instantiated. importobject optional an object containing the values to be imported into the newly-created instance, such as functions or webassembly.memory objects. there must be one matching property for each declared import of module or else a webassembly.linkerror is thrown. return value a promise that resolves to an webassembly.instance object. exceptions if either of the parameters are not of the correct type or structure, a typeerror is thrown. if the operation fails, the promise rejects with a webassembly.compileerror, webassembly.linkerror, or webassembly.runtimeerror, depending on the cause of the failure. examples note: you'll probably want to use webassembly.instantiatestreaming() in most cases, as it is more efficient than instanti...

Optional chaining (?.) - JavaScript
optional chaining when attempting to call a method which may not exist. this can be helpful, for example, when using an api in which a method might be unavailable, either due to the age of the implementation or because of a feature which isn't available on the user's device. using optional chaining with function calls causes the expression to automatically return undefined instead of throwing an exception if the method isn't found: let result = someinterface.custommethod?.(); note: if there is a property with such a name and which is not a function, using ?. will still raise a typeerror exception (someinterface.custommethod is not a function). note: if someinterface itself is null or undefined, a typeerror exception will still be raised (someinterface is null). if you expect that someinterfa...
...2019 function dosomething(oncontent, onerror) { try { // ... do something with the data } catch (err) { if (onerror) { // testing if onerror really exists onerror(err.message); } } } // using optional chaining with function calls function dosomething(oncontent, onerror) { try { // ... ...

delete operator - JavaScript
pression where expression should evaluate to a property reference, e.g.: delete object.property delete object['property'] parameters object the name of an object, or an expression evaluating to an object. property the property to delete. return value true for all cases except when the property is an own non-configurable property, in which case, false is returned in non-strict mode. exceptions throws typeerror in strict mode if the property is an own non-configurable property. description unlike what common belief suggests (perhaps due to other programming languages like delete in c++), the delete operator has nothing to do with directly freeing memory. memory management is done indirectly via breaking references. see the memory management page for more details. the delete operato...
...bal property using: object.getownpropertydescriptor(window, 'nameother'); // output: object {value: "xyz", // writable: true, // enumerable: true, // configurable: false} // since "nameother" is added using with the // var keyword, it is marked as "non-configurable" delete nameother; // return false in strict mode, this would have raised an exception. strict vs. non-strict mode when in strict mode, if delete is used on a direct reference to a variable, a function argument or a function name, it will throw a syntaxerror. therefore, to avoid syntax errors in strict mode, you must use the delete operator in the form of delete object.property or delete object['property']. object.defineproperty(globalthis, 'variable1', { value: 10, configurable...

typeof - JavaScript
ted as a type tag and a value. the type tag for objects was 0. null was represented as the null pointer (0x00 in most platforms). consequently, null had 0 as type tag, hence the "object" typeof return value. (reference) a fix was proposed for ecmascript (via an opt-in), but was rejected. it would have resulted in typeof null === 'null'. using new operator // all constructor functions, with the exception of the function constructor, will always be typeof 'object' let str = new string('string'); let num = new number(100); typeof str; // it will return 'object' typeof num; // it will return 'object' let func = new function(); typeof func; // it will return 'function' need for parentheses in syntax // parentheses can be used for determining the data type of expressions. let idata = 99; typeof...
...oped variables are in a "temporal dead zone" from the start of the block until the initialization is processed, during which, it will throw an error if accessed. typeof undeclaredvariable === 'undefined'; typeof newletvariable; // referenceerror typeof newconstvariable; // referenceerror typeof newclass; // referenceerror let newletvariable; const newconstvariable = 'hello'; class newclass{}; exceptions all current browsers expose a non-standard host object document.all with type undefined. typeof document.all === 'undefined'; although the specification allows custom type tags for non-standard exotic objects, it requires those type tags to be different from the predefined ones. the case of document.all having type 'undefined' is classified in the web standards as a "willful violation" of the...

<mstyle> - MathML
attributes dir overall directionality of formulas. possible values are either ltr (left to right) or rtl (right to left). decimalpoint this attribute is specifying the character for the alignment point within <mstack> and <mtable> columns, if the decimalpoint value is used to specify the alignment. ...
...ends on the multiplier specified in scriptsizemultiplier. scriptminsize specifies a minimum font size allowed due to changes in scriptlevel. the default value is 8pt. scriptsizemultiplier specifies the multiplier to be used to adjust font size due to changes in scriptlevel. the default value is 0.71. the <mstyle> element accepts all attributes of all presentation elements with the following exceptions: height, depth or width do not apply to <mglyph>, <mpadded> or <mtable>. rowalign, columnalign, or groupalign do not apply to <mtr>, <mlabeledtr>, <mtd> or <maligngroup>. lspace or voffset do not apply to <mpadded>. fontfamily does not apply to <mglyph>. align does not apply to <mtable> or <mstack>. index cannot be set on <mstyle>. src and alt on <mglyph> cannot be set on <mstyle>. act...

Web audio codec guide - Web media technologies
cations. unless there's a specific need for lossless compression, or the network bandwidth is guaranteed to be high enough to support it, a lossy compression scheme is a good choice. which one you choose depends on browser compatibility and the availability of any special features you may need the codec to support. usually the latency is not particularly important when streaming music. possible exceptions include looped music, where you need music to be able to play back uninterrupted over and over, or when you need to be able to play songs back to back with no gap between them. this can be particularly important for classical music, theatrical soundtracks, and for background music during gameplay. for general music playback, the three most likely candidates are mp3, aac, and vorbis. aac in a...
...n an audio layer iii track. if you need to minimize latency during music playback, you should strongly consider opus, which has the lowest range of latencies of the general-purpose codecs (5 ms to 66.5 ms, compared to at least 100 ms for the others). note: compatibility information described here is generally correct as of the time this article was written; however, there may be caveats and exceptions. be sure to refer to the compatibility tables before committing to a given media format. based on this, aac is likely your best choice if you can only support one audio format. of course, if you can provide multiple formats (for example, by using the <source> element within your <audio> and <video> elements), you can avoid many or all of those exceptions. example: music for download music be...

Same-origin policy - Web security
e these types of urls do not contain information about an origin server. for example, about:blank is often used as a url of new, empty popup windows into which the parent script writes content (e.g. via the window.open() mechanism). if this popup also contains javascript, that script would inherit the same origin as the script that created it. data: urls get a new, empty, security context. exceptions in internet explorer internet explorer has two major exceptions to the same-origin policy: trust zones if both domains are in the highly trusted zone (e.g. corporate intranet domains), then the same-origin limitations are not applied. port ie doesn't include port into same-origin checks. therefore, https://company.com:81/index.html and https://company.com/index.html are considered the sam...
... changing origin a page may change its own origin, with some limitations. a script can set the value of document.domain to its current domain or a superdomain of its current domain. if set to a superdomain of the current domain, the shorter superdomain is used for same-origin checks. ...

Cross-domain Content Scripts - Archive of obsolete content
...

self - Archive of obsolete content
lf.options.a); port you can use port to receive messages from, and send messages to, the main add-on code. see the documentation for port. methods the self object has four methods, which enable the content script to send messages to, and receive messages from, the main add-on code. this is an older api than the api provided by port, and for most purposes the port api is a better choice. the exception is the context-menu module, which still uses postmessage. postmessage() send a message from a content script to a listener in the main add-on code: self.postmessage(contentscriptmessage); this takes a single parameter, the message payload, which may be any json-serializable value. on() start listening to messages from the main add-on code: self.on("message", function(addonmessage) { // ...

Content Scripts - Archive of obsolete content
stmessage api before the port object was added, add-on code and content scripts communicated using a different api: the content script called self.postmessage() to send and self.on() to receive the add-on script called worker.postmessage() to send and worker.on()to receive the api is still available and documented, but there's no reason to use it instead of the port api described here. the exception is the context-menu module, which still uses postmessage. content script to content script content scripts can only communicate with each other directly if they have been loaded into the same context. for example, if a single call to tab.attach() attaches two content scripts, then they can see each other directly, just as page scripts loaded by the same page can. but if you call tab.attach() tw...

Module structure of the SDK - Archive of obsolete content
ame way it would load a local module. for example, to load from main: // main.js code var geo = require("./dependencies/geolocation"); freezing the sdk freezes the exports object returned by require. so a if you import a module using require, you can't change the properties of the object returned: self = require("sdk/self"); // attempting to define a new property // will fail, or throw an exception in strict mode self.foo = 1; // attempting to modify an existing property // will fail, or throw an exception in strict mode self.data = "foo"; using modules from outside the add-on sdk you can use commonjs modules outside the add-on sdk, in any environment where you can use components.utils.import. just call the following: const { require } = cu.import("resource://gre/modules/commonjs/toolki...

request - Archive of obsolete content
es the request, the request object emits a "complete" event. registered event listeners are passed a response object. each request object is designed to be used once. attempts to reuse them will throw an error. since the request is not being made by any particular website, requests made here are not subject to the same-domain restriction that requests made in web pages are subject to. with the exception of response, all of a request object's properties correspond with the options in the constructor. each can be set by simply performing an assignment. however, keep in mind that the same validation rules that apply to options in the constructor will apply during assignment. thus, each can throw if given an invalid value. the example below shows how to use request to get the most recent tweet from...

event/core - Archive of obsolete content
an event listener that is called only once: the next time an event of the specified type is emitted on the given event target. parameters target : object event target object. type : string the type of event. listener : function the listener function that processes the event. emit(target, type, message, arguments) execute each of the listeners in order with the supplied arguments. all the exceptions that are thrown by listeners during the emit are caught and can be handled by listeners of 'error' event. thrown exceptions are passed as an argument to an 'error' event listener. if no 'error' listener is registered exception will be logged into an error console. parameters target : object event target object. type : string the type of event. message : object|number|string|boolean first ...

event/target - Archive of obsolete content
: let { emit } = require('sdk/event/core'); target.on('message', function onmessage(message) { console.log('listener triggered'); target.on('message', function() { console.log('nested listener triggered'); }); }); emit(target, 'message'); // info: 'listener triggered' emit(target, 'message'); // info: 'listener triggered' // info: 'nested listener triggered' exceptions in the listeners can be handled via 'error' event listeners: target.on('boom', function() { throw error('boom!'); }); target.once('error', function(error) { console.log('caught an error: ' + error.message); }); emit(target, 'boom'); // info: caught an error: boom! if there is no listener registered for error event or if it also throws exception then such exceptions are logged into a consol...

io/file - Archive of obsolete content
de. if "b" is not present or mode is not given, the file contents will be returned in text mode. returns string : a string containing the file's entire contents. remove(path) removes a file from the file system. to remove directories, use rmdir. parameters path : string the path of the file to remove. rmdir(path) removes a directory from the file system. if the directory is not empty, an exception is thrown. parameters path : string the path of the directory to remove. isfile(path) returns true only if this path specifies a file. const fileio = require("sdk/io/file"); let path = "/users/work/"; let list = fileio.list(path); for (i = 0; i < list.length; i++) { let item = fileio.join(path, list[i]); if (fileio.isfile(item)) { console.log(item + " is a file"); } else { ...

loader/sandbox - Archive of obsolete content
to all the xpcom components. optionally the sandbox function can be passed a second argument (see sandbox documentation on mdn for details). evaluate code module provides evaluate function that lets you execute code in the given sandbox: evaluate(scope, 'var a = 5;'); evaluate(scope, 'a + 2;'); //=> 7 more details about evaluated script may be passed via optional arguments that may improve exception reporting: // evaluate code as if it was loaded from 'http://foo.com/bar.js' and // start from 2nd line. evaluate(scope, 'a ++', 'http://foo.com/bar.js', 2); version of javascript can be also specified via an optional argument: evaluate(scope, 'let b = 2;', 'bar.js', 1, '1.5'); // throws cause `let` is not defined in js 1.5. load scripts this module provides a limited api for loading scripts...

system/unload - Archive of obsolete content
nsures that this wrapper method is called when the object's module is unloaded. therefore, when you register an object with ensure(), you can call its destructor method yourself, you can let it happen for you, or you can do both. the destructor will be called with a single argument describing the reason for the unload; see when(). if object does not have the expected destructor method, then an exception is thrown when ensure() is called. parameters object : object an object that defines a destructor method. name : string optional name of the destructor method. default is unload. when(callback) registers a function to be called when the module is unloaded. parameters callback : function a function that will be called when the module is unloaded. it is called with a single argument, one ...

system/xul-app - Archive of obsolete content
for more information, see the mdn documentation. globals functions is(name) checks whether the host application is the given application. parameters name : string a host application name. returns boolean : true if the host application is name and false otherwise. isoneof(names) checks whether the host application is one of the given applications. parameters names : array an array of host application names. ...

ui/button/action - Archive of obsolete content
passing in the window or tab you are interested in, and it will return the state: var labelforactivetab = button.state("tab").label; to learn more about this, see the api documentation for state(). destroying buttons when you've finished with a button, destroy it by calling its destroy() method. after that, any attempts to access any of its properties or to call any of its methods will throw exceptions. globals constructors actionbutton(options) creates an action button. parameters options : object required options: name type id string the button's id. this is used internally to keep track of this button. the id must be unique within your add-on. label string the button's human-readable label. when the button is in the to...

ui/button/toggle - Archive of obsolete content
window', null); // now that the state hierarchy is clean, set the // tab state for the current tab let { checked } = this.state('tab'); this.state('tab', {checked: !checked}); } }); destroying buttons when you've finished with a button, destroy it by calling its destroy() method. after that, any attempts to access any of its properties or to call any of its methods will throw exceptions. globals constructors togglebutton(options) creates a toggle button. parameters options : object required options: name type id string the button's id. this is used internally to keep track of this button. the id must be unique within your add-on. label string the button's human-readable label. when the button is in the too...

util/match-pattern - Archive of obsolete content
the regular expression is subject to restrictions based on those applied to the html5 pattern attribute. in particular: the pattern must match the entire value, not just any subset. for example, the pattern /moz.*/ will not match the url http://mozilla.org. the expression is compiled with the global, ignorecase, and multiline flags disabled. the matchpattern constructor will throw an exception if you try to set any of these flags. example pattern example matching urls example non-matching urls /.*moz.*/ http://foo.mozilla.org/ http://mozilla.org https://mozilla.org http://foo.com/mozilla http://hemozoon.org mozscheme://foo.org http://foo.org /https:\/\/www\.moz.*/ https://www.mozilla.org https://www.mozzarella.com ...

window/utils - Archive of obsolete content
private windows will not be included in this list if your add-on has not opted into private browsing. ...

Unit Testing - Archive of obsolete content
which is an assert object. assert is supplied by the test/assert module and implements the commonjs unit testing specification. the first two functions call atob() and btoa() and use assert.ok() to check that the output is as expected. the second function tests the module's error-handling code by passing an empty string into atob() and using assert.throws() to check that the expected exception is raised. at this point your add-on ought to look like this: /base64 /data icon-16.png package.json readme.md index.js base64.js /test test-base64.js now execute jpm --verbose test from the add-on's root directory. you should see something like this: console.info: jpm-utest: executing './test/test-base64.test atob' console.info: j...

File I/O - Archive of obsolete content
file = components.classes["@mozilla.org/file/local;1"]. createinstance(components.interfaces.nsilocalfile); file.initwithpath("/home"); note: the path should be in the "native" form (for example"c:\\windows"). if you need to use file:// uris as initializers, see discussion of nsiioservice below. note: you can still get a file object even if the specified file does not exist, and no exception will be thrown. an exception is thrown only when methods that require the file to exist are called, e.g., isdirectory(), moveto(), and so on. getting files in special directories components.utils.import("resource://gre/modules/fileutils.jsm"); // get the "data.txt" file in the profile directory var file = fileutils.getfile("profd", ["data.txt"]); or the same without using fileutils.jsm: //...

JS XPCOM - Archive of obsolete content
siprefbranch2 interface. determining which interfaces an xpcom component supports to display a list of all interfaces that an xpcom component supports, do the following: // |c| is the xpcom component instance for each (i in components.interfaces) { if (c instanceof i) { alert(i); } } in this context, instanceof is the same as queryinterface except that it returns false instead of throwing an exception when |c| doesn't support interface |i|. another difference is that queryinterface returns an object, where as instanceof returns a boolean. xpcomutils - about protocol handler this example implements a quick about protocol handler in js using xpcomutils.jsm. components.utils.import("resource://gre/modules/services.jsm"); components.utils.import("resource://gre/modules/xpcomutils.jsm"); const c...

Common Pitfalls - Archive of obsolete content
ns return rv; } or, if the code can include nsnetutil.h: nscomptr<nsiuri> uriobj; nsresult rv = ns_newuri(getter_addrefs(uriobj), uristring, uricharset, baseuri); in all cases the baseuri can be null if the uristring should be treated as an absolute uri and uricharset can be null if there is no clear origin charset for the string (e.g. it's something the user typed in the url bar). the one exception to all of the above, that is the one case in which creating a specific uri class via createinstance is acceptable, is when one is implementing a protocol handler's newuri method. in that case you may not be able to use the i/o service because that service calls the newuri method on the appropriate protocol handler, which may be your own handler. how to do security checks for uri loads before l...

Default Preferences - Archive of obsolete content
and mozilla will read it and set the appropriate preferences. the actual file, despite having .js extension, is not a javascript file. you may not set variables inside of it, nor may do any kind of program flow control (ifs, loops etc.) nor even calculated values (i.e. 3600 * 24 * 5). doing so will cause mozilla to stop processing your preferences file without any notification, warning, error, or exception. think of it more as an .ini file. comments are perfectly acceptable. inside your file you set preferences using the pref() function: pref("name", "value") example: pref('extensions.defaultprefs.example.int', 1); pref('extensions.defaultprefs.example.float', 0.1); pref('extensions.defaultprefs.example.string', 'fadf'); pref('extensions.defaultprefs.example.bool', true); notice that unlike when...

Jetpack Processes - Archive of obsolete content
or being unrooted and then unreachable. the callback is only called from the process that the handle was not garbage collected in. read-write. special messages core:process-error(context) when the jetpack process crashes, this message is sent to the parent. if a crash report minidump is available, the context.dumpid property will list the minidump id of the crash report that was collected. core:exception(error) when an exception occurs in a jetpack script and is not caught, this message is sent to the parent. the error object contains the following properties: filename, linenumber, and message. history see bug 556846 and bug 578821 for details. sample code for example code, check out the unit tests. see also nsijetpackservice nsijetpack ...

Appendix F: Monitoring DOM changes - Archive of obsolete content
ens before the page is fully loaded. this method works particularly well with services like google instant, and the gawker family of sites. network listeners ajax-based page changes are almost universally tied to xmlhttprequests. these requests can be tracked from chrome code using a variety of methods, including web progress listeners, http observers, and content policies. while these are not exceptionally efficient (they run for every http request, and considerably more often for some methods), they work very well for certain applications pure css pure css can be more powerful than most people suspect. it is often possible to do things for which people have traditionally resorted to javascript with css alone. in particular, the ::before and ::after pseudo-elements, and pseudo-classes like :h...

Getting Started with Firefox Extensions - Archive of obsolete content
es.required preference in about:config. install hello world click the above link and then click "allow" in the pop-up bubble. you should see another pop-up telling you that you are installing an unverified add-on. click "install". after the extension is installed, you'll be asked to restart firefox. installing, uninstalling, enabling and disabling add-ons require a restart to complete, with the exception of npapi plugins, add-ons sdk extensions and bootstrapped extensions. this is an important point to keep in mind if you're building an extension that manipulates other extensions or themes. after installing, look at the main firefox window and see if you notice anything different. did you see it? there's a new menu on the main menu, labeled "hello world!". if you open the menu and then the m...

Handling Preferences - Archive of obsolete content
if you are going to use xpcom, you should always set a default value to your preferences, or use a try / catch block to prevent unhandled errors. preference listeners the xpcom way to add a listener was mentioned in the xpcom section when describing the queryinterface method: this._prefservice.queryinterface(ci.nsiprefbranch2); this._prefservice.addobserver(pr...

Intercepting Page Loads - Archive of obsolete content
e the use of the binary mask & operator. to detect if this is a frame being loaded or not, you can do this: if (awebprogress.domwindow != awebprogress.domwindow.top) { // this is a frame. } in this case, the url can be obtained from arequest.name. make sure you access it from inside the state validation if condition. there may be other cases where accessing this property will throw an exception. canceling the request works just like with onlocationchange. see "recognizing page load failure" at mozilla.dev.extensions for tips on detecting connection failures and http response codes. xpcom solutions there are a couple more solutions you may be interested in trying if the previous ones are insufficient. these require creating xpcom components that implement existing firefox inte...

Local Storage - Archive of obsolete content
is a debug message."); this._logger.trace("this is a trace message."); you can filter the output of the global logger or any specific logger instance by setting the level property. during development you should use the "all" level, but for release versions it's usually better to move the level up to "warn", so that the log is compact and execution is more efficient. note: we recommend that all exception catch blocks include some logging at the error or warn levels, and in general you should use logging freely in order to have as much information as possible to fix bugs and know what is going on. don't log inside functions that are called too often, such as mouseover event handlers, or certain http activity listeners. this impacts performance and fills the log with useless messages. we normally a...

The Box Model - Archive of obsolete content
s, thus preventing them from growing or shrinking too much. all css properties involving lengths should be handled with caution. we recommended that you use proportional units (em, %) instead of absolute units (px) whenever possible. using the former allows the ui to scale proportionately depending on font size settings, which are often changed by users with accessibility limitations. a common exception to this rule is when your css is directly related to images, where you'll usually handle measurements in pixels (px). also, just like in html, you can control the dimensions of inflexible elements using the width and height css properties and attributes. these attributes won't have any effect on flexible elements. margins, paddings and spacers margins and paddings are frequently used in both...

Extensions support in SeaMonkey 2 - Archive of obsolete content
in 2.1 url in firefox url in seamonkey chrome://browser/content/bookmarks/bookmarkspanel.xul chrome://communicator/content/bookmarks/bm-panel.xul chrome://browser/content/places/places.xul chrome://communicator/content/bookma...rksmanager.xul thunderbird uses mostly the same chrome urls for overlaying as seamonkey. there are exceptions, but these are few and far between. seamonkey also uses different ids for the menu items. some important menu ids are listed below, menu ids are based on firefox 3 source code: menu id in firefox menu id in seamonkey 1.x and 2.0 seamonkey 2.1 overlays menu_filepopup menu_filepopup menu_filepopup file menu popup men...

Setting up an extension development environment - Archive of obsolete content
efore the automatic restart happens. to see them, prevent the automatic restart by setting the environment no_em_restart to 1 before starting the application.) nglayout.debug.disable_xul_fastload = true. for gecko 2.0+ (firefox 4.0+). see this bug for more information. although the bug has been closed, it is believed that this pref is still relevant. you might also want to set dom.report_all_js_exceptions = true. see exception logging in javascript for details. devtools.errorconsole.deprecation_warnings = true. detect deprecated code use. warning: never set nglayout.debug.disable_xul_fastload to true in a production environment; it exists solely to aid in debugging. in particular, add-ons should never change this preference. note: the error console is disabled by default starting in gecko ...

Tabbed browser - Archive of obsolete content
but if its an ajax call you may end up here } } } }; here's a cleaner example of the same thing: cu.import('resource://gre/modules/services.jsm'); var httprequestobserver = { observe: function (subject...

Notes on HTML Reflow - Archive of obsolete content
nuing frames (or continuations ) created for subsequent lines. html uses a flow based layout model, meaning that most of the time it is possible to compute the geometry in a single pass. elements later "in the flow" typically do not affect the geometry of elements that are earlier "in the flow", so layout can proceed left-to-right, top-to-bottom through the document. there are exceptions to this rule: most notably, html tables may require more than one pass. the xul box layout model, on the other hand, is constraint based , meaning that geometric preferences and constraints of neighboring elements are taken into consideration before the elements' final geometry can be computed. the box is the geometric primitive for the xul layout model. all html reflow, includ...

Same-origin policy for file: URIs - Archive of obsolete content
bar.html and you have navigated to it from the file index.html, the load will succeed only if bar.html is either in the same directory as index.html or in a directory contained within the same directory as index.html. this policy affects anything that does same-origin checks, including xmlhttprequest, xslt, and xbl. for cross-window dom access, each file is treated as a separate origin, with one exception: if a file is loaded from another file that would otherwise be able to load it following this same-origin policy, they are considered to have the same origin. this load can occur through a subframe, link, location set, call to window.open(), or the like. for example, if the file /home/user/foo.html is a frameset and one of the frames is /home/user/subdir/bar.html, the frame and frameset are cons...

Error Console - Archive of obsolete content
content. the error console is a tool available in most mozilla-based applications that is used for reporting errors in the application chrome and in web pages user opens. it reports javascript-related errors and warnings, css errors and arbitrary messages from chrome code. in firefox, the error console can be opened from the tools menu or by ctrl-shift-j. for information about what javascript exceptions get logged into the error console, and how to make all exceptions get logged, read the article exception logging in javascript. see setting up extension development environment#development preferences for the preferences you should set if you want to see errors from firefox and extensions in the error console. before gecko 1.8.1 (firefox 2), it was called javascript console (see bug 265871). ...

Java in Firefox Extensions - Archive of obsolete content
one example seems to be the fact that the "java" global is not immediately available if the extension operates in a sidebar (using settimeout solved it at least). i've had problems with stability in the latest xquseme when testing in firefox 3.5b4, especially apparently on linux (i haven't so far been able to...

Basics - Archive of obsolete content
console writes some information to the error console. you can find the console in the extra menu of firefox. the namespace for this api is console. methods info()this method does stuff. log(stringstring)this method writes a notification message to the console. stringthe message to add to the consolestring console.log("hello world!"); arn()this method does stuff. error()this method does stuff. exception()this method does stuff. logfromcaller()this method does stuff. class notifications the notification box appears at the bottom right corner of the browser and displays important information to the user. the namespace for this class is jetpack.notificaitons. methods show(titlestringbodystringiconstring)draws a notification box. titlethe head of the notification message.string bodythe messagestrin...

Twitter - Archive of obsolete content
it fails to complete. the library simply passes them to jquery.ajax(), and so they are called like so: success(data, textstatus) data is twitter's decoded json response. textstatus is a simple string describing the status. error(xmlhttprequest, textstatus, errorthrown) xmlhttprequest is the xhr used in the request. textstatus is a simple string describing the type of error. errorthrown is an exception object, if one was thrown. the examples below all use this first, simpler style. the second style will be familiar if you have used jquery.ajax() -- in fact the object is passed as-is (almost) to it. in other words, define a data property that is itself an object whose properties correspond to the parameters of the twitter method. with this style you can use any of the various jquery.ajax() op...

jspage - Archive of obsolete content
.nocache){var f="nocache="+new date().gettime();g=(g)?f+"&"+g:f; }var e=b.lastindexof("/");if(e>-1&&(e=b.indexof("#"))>-1){b=b.substr(0,e);}if(g&&a=="get"){b=b+(b.contains("?")?"&":"?")+g;g=null;}this.xhr.open(a.touppercase(),b,this.options.async); this.xhr.onreadystatechange=this.onstatechange.bind(this);this.headers.each(function(m,l){try{this.xhr.setrequestheader(l,m);}catch(n){this.fireevent("exception",[l,m]); }},this);this.fireevent("request");this.xhr.send(g);if(!this.options.async){this.onstatechange();}return this;},cancel:function(){if(!this.running){return this; }this.running=false;this.xhr.abort();this.xhr.onreadystatechange=$empty;this.xhr=new browser.request();this.fireevent("cancel");return this;}});(function(){var a={}; ["get","post","put","delete","get","post","put","delete"].each(...

Metro browser chrome tests - Archive of obsolete content
owser/metro/base/tests/mochitest/head.js. you may add additional common utils and helpers to head.js. be careful about changing existing helpers as changes may impact tests in other libraries. static content for tests static content (html files, images, etc.) should be stored in sub directories to avoid polluting the main test directory. sub directories for larger test suites may also be created. exceptions in tests any exceptions thrown under test() will be caught and reported as a general failure. setup(), teardown(), and run() each have individual exception handlers to prevent one method from interfering with the execution of another. an exception in any of these methods will cause a test failure. additional built-in framework test checks will run after the completion of each individual test ins...

Mozilla Application Framework in Detail - Archive of obsolete content
t browsing anywhere across applications, computing platforms and devices. this innovation in browser technology offers small size, speed and industry leading standards support. gecko is the premier cross-platform, full-featured, mature and well-tested layout engine available, providing robust and high quality support for a massive array of standards. its ability to render web content correctly is exceptional. gecko consists roughly of an html parser and xml parser, a dom implementation, a css parser and style system, and the code for css-based and html-based layout and rendering. as personal connectivity expands from the desktop computer to new web-enabled products and devices, gecko is a browser engine that has been designed from the ground up to power a new generation of desktop browsers and brow...

LIR - Archive of obsolete content
le conversions 108 i2q quad 64 bit sign-extend int to quad 109 ui2uq quad 64 bit zero-extend unsigned int to unsigned quad 110 q2i integer 64 bit truncate quad to int (removes the high 32 bits) 111 i2d double convert int to double 112 ui2d double convert unsigned int to double 113 d2i integer convert double to int (no exceptions raised) 114 dasq quad 64 bit interpret the bits of a double as a quad 115 qasd double 64 bit interpret the bits of a quad as a double overflow arithmetic 116 addxovi integer add int and exit on overflow 117 subxovi integer subtract int and exit on overflow 118 mulxovi integer multiply int and exit on overflow 119 addjovi ...

Reading textual data - Archive of obsolete content
should happen with byte sequences that do not correspond to a valid character. the last (4th) argument to init specifies which character they get replaced with; nsiconverterinputstream.default_replacement_character is u+fffd replacement character, which is often a good choice. if you do not want any replacement, you can specify 0x0000 as replacement character; that way, readstring will throw an exception when reaching unsupported bytes. reading lines the nsiunicharlineinputstream interface provides an easy way to read entire lines from a unichar stream. it can be used like nsilineinputstream, except that it supports non-ascii characters, and has no problems with charsets with embedded nulls (like utf-16 and utf-32). it can be used like this: var charset = /* need to find out what the characte...

Frequently Asked Questions - Archive of obsolete content
ozilla's svg implementation compare to adobe's? mozilla's native implementation is less complete than adobe svg viewer's in general. there are major features such as filters and smil based animation that have still to be implemented in mozilla. however, mozilla's implementation already supports some things that adobe's lacks, particularly parts of the xml and svg doms. for example we support svg exceptions and svgtransform objects. how do you install adobe's svg viewer in mozilla? the svg project is about mozilla's native implementation of svg, not adobe/corel/whoever's plug-in. however, we might as well answer this question to save you searching for this information elsewhere. see these install instructions on mozdev.org. it's also useful to know that you can check whether mozilla has recognise...

Supporting private browsing mode - Archive of obsolete content
nsiobserverservice); this._os.addobserver(this, "private-browsing", false); this._os.addobserver(this, "quit-application", false); try { var pbs = components.classes["@mozilla.org/privatebrowsing;1"] .getservice(components.interfaces.nsiprivatebrowsingservice); this._inprivatebrowsing = pbs.privatebrowsingenabled; } catch(ex) { // ignore exceptions in older versions of firefox } }, observe : function (asubject, atopic, adata) { if (atopic == "private-browsing") { if (adata == "enter") { this._inprivatebrowsing = true; if (this.watcher && "onenterprivatebrowsing" in this._watcher) { this.watcher.onenterprivatebrowsing(); } } else if (adata == "exit") { this._inpr...

Abc Assembler Tests - Archive of obsolete content
findproperty compare_stricteq pushstring "null lessequals null" // testname pushtrue // expected pushnull pushnull lessequals // actual callpropvoid compare_stricteq 3 // use .try / .catch to catch typeerror // convert_o null .try { pushnull convert_o pop findproperty fail pushstring "convert_o null" pushstring "exception should have been thrown: typeerror: error #1009: cannot access a property or method of a null object reference." getlocal1 callpropvoid fail 3 jump finished_convert_o_null } .catch { getlocal0 pushscope setlocal2 // save typeerror findproperty compare_typeerror pushstring "convert_o null" // test name pushstring "t...

When To Use ifdefs - Archive of obsolete content
lication ifdefs should only be made in application-specific code. this is the trickiest kind of ifdef, because it is frequently hard to determine what code is "shared" and what code is "application-specific". as a general rule, any code in tier 2, tier 9, or tier 50 is shared code, and should not have application-specific ifdefs. any code in later tiers is application-specific. this rule has many exceptions, some of which are listed here: the code in editor/ui/ is built by the suite, standalone composer, and thunderbird, but it is considered application-specific. the code in xpfe/ (except for xpfe/appshell/ and xpfe/components/shistory/) is a hodgepodge mess of "toolkit" and "application-specific" code. this code is all going to be moved elsewhere (most of it to toolkit/ or suite/), but for the ...

Writing textual data - Archive of obsolete content
ering). passing 0 ensures that data will be immediately written to the underlying stream; however, for better perfomance you should pass a value like 4096 instead. unsupported characters you can specify what should happen with characters that are not supported by the selected character encoding. the last argument to init specifies that: 0x0000 means that writing unsupported characters throws an exception (with an error code of ns_error_loss_of_significant_data), and no data will be written. to instead write a replacement character in such cases, specify the character instead of 0x00: os.init(fos, charset, 0, "?".charcodeat(0)); you can, of course, replace the "?" in that example with any other character. you can also specify any unicode character u+abcd directly as 0xabcd. note: if the repla...

Anonymous Content - Archive of obsolete content
pped and flow proceeds to the next phase. whenever an event is retargeted, the target field of the event is set to the bound element. the original anonymous content responsible for the event can be obtained from a new field of the event object: originaltarget. the action taken (retarget vs. stop) is specific to the event type. in general, ui events are retargeted and mutation events are stopped. exceptions to the rule are noted below. focus and blur events when a focus or blur event crosses a scope boundary, the bound element is checked to see if it is focusable (i.e., if the user agent would normally fire a focus or blur event on the element). if the bound element is focusable, then the event is retargeted. if not, then the event is stopped. if anonymous content underneath a focusable bound ele...

XML in Mozilla - Archive of obsolete content
ylesheets with xml documents, and namespaces in xml. the core support is very good with few bugs. dtds and other external entities mozilla does not load external entities from the web. mozilla can load external entities whose system identifier uses the chrome protocol. this feature is used mainly to localize mozilla to different languages (the ui strings are stored in external dtd files). another exception is an entity whose system identifier is a relative path, and the xml declaration states that the document is not standalone (default), in which case mozilla will try to look for the entity under <bin>/res/dtd directory. mozilla may also make an exception with xhtml documents, see below. mozilla will read internal (dtd) subsets, and in special circumstances external dtds as explained above and wil...

Install script template - Archive of obsolete content
odes need some memory var err; // error return codes when we try and install to the current browser var errblock1; // error return codes when we try and do a secondary installation var errblock2 = 0; // global variable containing our secondary install location var secondaryfolder; //special error values used by the cycore developers (www.cycore.com) who helped make this install script var exceptionoccurederror = -4711; var winregisnullerror = -4712; var invalidrootkeyerror = -4713; var registrykeynotwritableerror = -4714; //initinstall block //the installation is initialized here -- if we fail here, cancel the installation // initinstall is quite an overloaded method, but i have invoked it here with three strings // which are globally defined err = initinstall(so...

Getting File Information - Archive of obsolete content
ject has a number of useful attributes which may be used to retrieve information about a file. two useful attributes filesize and lastmodifiedtime (nsifile.attributes) provide a means of retrieving the size of a file and the time when the file was last changed. file size the filesize (nsifile.attributes) attribute holds the size of a file in bytes. if the file does not exist, a 'file not found' exception will occur. you can catch this exception with a try-catch block, but it is better to use nsifile.exists() to check first. this example will check if a file on the desktop exists and set the variable 'filesize' to the size of the file. if the file is not present, the 'filesize' variable will not be changed from the default value of 0. var filesize = 0; var file = io.getfile("desktop", "saved file...

How to Quit a XUL Application - Archive of obsolete content
o close each xul window, but the xul window can cancel the quit // process if there is unsaved data. eforcequit will quit no matter what. ...

Index - Archive of obsolete content
9 actions xul, xul_template_guide the content to generate in a template is specified using the action element which should either be the next sibling of the query element (if no rules need be specified) or be a direct child of a rule element. the content to generate goes directly inside the action element. this content will be copied for each matching result (though see below for an exception) and inserted into the document. let's look at a simple example first. 920 additional navigation xul, xul_template_guide the triples used so far have all had variables in both the subject and object. however, a string value may be used instead. since the subject of an rdf arc is always a resource, the subject may be a resource uri. the object attribute may be a resource uri o...

Actions - Archive of obsolete content
« previousnext » the content to generate in a template is specified using the <xul:action> element which should either be the next sibling of the <xul:query> element (if no rules need be specified) or be a direct child of a <xul:rule> element. the content to generate goes directly inside the action element. this content will be copied for each matching result (though see below for an exception) and inserted into the document. let's look at a simple example first. <vbox datasources="http://www.xulplanet.com/ds/sample.rdf" ref="http://www.xulplanet.com/rdf/a"> <template> <query> <content uri="?start"/> <triple subject="?start" predicate="http://www.xulplanet.com/rdf/relateditem" object="?relateditem"/> </query> <action> ...

Multiple Rule Example - Archive of obsolete content
le, despite that they both store the value of the title predicate. there is no reason for this -- it is only used in this example to show that there is no connection between the variables used in the two rules. you can use different variables if it makes sense in the context of the template or the data, although in this example it would seem more reasonable to use the same variable name. the only exception to this is that the container and member variables (those that are referred to in the uri attributes), must be the same in all rules. in this example, the container variable is ?start and the member variable is ?photo. if different variables were used for these, the rules would not work properly. the reason for this is due to the manner in which the builder processes the data. looking back at the...

Templates - Archive of obsolete content
to guess what would happen if the second rule was removed. the result would be a single spacer displayed but no bookmarks because they don't match any of the rules. put simply, a rule matches if all of the attributes placed on the rule element match the corresponding attributes on the rdf resource. in the case of an rdf file, the resources would be the description elements. there are some small exceptions however. you cannot match based on the attributes id, rdf:property or rdf:instanceof. because you can just use your own attributes with your own namespace, it probably doesn't really matter anyway. note that a template with no rules in it, as in the first example, is really equivalent functionally to a template with a single rule with no attributes. next, we'll look at using templates with tre...

XPCOM Interfaces - Archive of obsolete content
var alocalfile = components.classes["@mozilla.org/file/local;1"].createinstance(components.interfaces.nsilocalfile); this will do the same thing as the two lines but in one line of code. it eliminates the need to create the instance and then query it for an interface in two separate steps. if you call queryinterface() on an object and the requested interface is not supported by an object, an exception is thrown. if you're not sure that an interface is supported by a component, you can use the instanceof operator to check: var afile = components.classes["@mozilla.org/file/local;1"].createinstance(); if (afile instanceof components.interfaces.nsilocalfile){ // do something } the instanceof operator returns true if afile implements the nsilocalfile interface. this also has the side effect of...

XUL accessibility guidelines - Archive of obsolete content
rm elements should not be used to label other form elements. when form elements are encapsulated in a groupbox with a caption, assistive technologies such as screen readers will read the caption along with the label to the form element. for example, under the privacy section of preferences there are three groupboxes captioned: history, cookies, and private data. if the user were to tab to the "exceptions..." button they would hear "cookies {pause} exceptions {pause} button." the next tab would read "cookies {pause} keep until {pause} they expire {pause} one of three {pause} combobox." if the screen reader only read the label, then the user would have to guess what the "exceptions" button or the "keep until" combobox was referring to. groupboxes are essential for radiogroups or groups of checkbo...

Building XULRunner with Python - Archive of obsolete content
ton activated') window.addeventlistener('load', onload, false) one possible gotcha is that the default python path used to find modules that areimported explicitly includes the xulrunner executable directory and the directory that is current when xulrunner launches. however it does not include any path related to the xul application being run. some work around will need to be found. unhandled exceptions are displayed in the javascript error console which can be opened usingxulrunner -jsconsole. one solution is to puttry .... except: print_exc() round any event handler to print tracebacks to stdout and use a python console to catch that output. the jsconsole can also be open and used from code, for example (in javascript) function openjavascriptconsole() { var wwatch = components.classes["@m...

Archived Mozilla and build documentation - Archive of obsolete content
onsole the error console is a tool available in most mozilla-based applications that is used for reporting errors in the application chrome and in web pages user opens. it reports javascript-related errors and warnings, css errors and arbitrary messages from chrome code. in firefox, the error console can be opened from the tools menu or by ctrl-shift-j. exception logging in javascript technical review completed. existing content this is a list of existing mozilla.org documentation. it needs to be checked, prioritized, and migrated. extension frequently asked questions this is quick set of answers to the most common issues with extension development. they are currently written with mostly...

2006-11-24 - Archive of obsolete content
nt.mk build_all". joe is asking for help on a possible solution to fix his problem. building xpcom components with msvs 2005 november 21st: buffaloaf is having trouble getting a personal xpcom component to work under xulrunner when compiled with msvs 2005. luke is migrating all of his code to compile with vc8 and is having some problems. he is receiving the following error: error: uncaught exception: [exception... "component returned failure code: 0x80570016 (ns_error_xpc_gs_returned_failure) [nsijscid.getservice]" nsresult: "0x80570016 (ns_error_xpc_gs_returned_failure)" location: "js frame :: chrome://modzilla/content/js/pkg_zillacom.js :: <top_level> :: line 1202" data: no] he is running xulrunner v1.8.0.4. luke wants to know if compiling xulrunner with a static crt is better or wor...

2006-11-24 - Archive of obsolete content
...

NPN_GetURLNotify - Archive of obsolete content
lug-in-private value for associating the request with the subsequent npp_urlnotify() call, which passes this value (see description below). returns if successful, the function returns nperr_no_error. if unsuccessful, the plug-in is not loaded and the function returns an error code. for possible values, see error codes. description npn_geturlnotify() works just like npn_geturl(), with one exception: npn_geturlnotify() notifies the plug-in instance upon successful or unsuccessful completion of the request by calling the plug-in's npp_urlnotify() function and passing it the notifydata value. npn_geturlnotify() typically handles the url request asynchronously. it returns immediately and only later handles the request and calls npp_urlnotify(). this notification is the only way the plug-in can...

NPN_PostURLNotify - Archive of obsolete content
-private value for associating the request with the subsequent npp_urlnotify call, which returns this value (see description below). returns if successful, the function returns nperr_no_error. if unsuccessful, the plug-in is not loaded and the function returns an error code. for possible values, see error codes. description npn_posturlnotify functions identically to npn_posturl, with these exceptions: npn_posturlnotify supports specifying headers when posting a memory buffer. npn_posturlnotify calls npp_urlnotify upon successful or unsuccessful completion of the request. for more information, see npn_posturl. npn_posturlnotify is typically asynchronous: it returns immediately and only later handles the request and calls npp_urlnotify. if this function is called with a target parameter ...

NPObject - Archive of obsolete content
eference count for the object. ...

NPAPI plugin reference - Archive of obsolete content
npn_reloadplugins reloads all of the installed plugins. npn_removeproperty removes a property from the specified npobject. npn_requestread requests a range of bytes from a seekable stream. this initiates a read operation; the actual data is received through subsequent calls to npp_writeready() and npp_write(). npn_retainobject increments the reference count of the given npobject. npn_setexception a plugin can call this function to indicate that a call to one of the plugin's npobjects generated an error. npn_setproperty sets the value of a property on the specified npobject. npn_setvalue implemented by browsers. this call is used to inform the browser of variable information controlled by the plugin. npn_setvalueforurl allows a plugin to change the stored information associated with...

Using workers in extensions - Archive of obsolete content
which stock is being monitored. if there is no data field, the refreshinformation() method is called to fetch the latest information about the stock and pass it back to the main thread. this provides a way for the main thread to specifically request that the worker update the stock information at once. the refreshinformation() method is fairly similar to the previous versions, with two notable exceptions: if the ticker symbol has not been set yet, an exception is thrown (lines 4-6). when the result is received from xmlhttprequest, instead of immediately updating the displayed information in the status bar, a message is sent to the main thread using the worker's postmessage() method. this is because only the main thread is allowed to access the user interface. the main thread the changes h...

Using JavaScript Generators in Firefox - Archive of obsolete content
yield; } generator = databaseoperation(); generator.next(); ...

Debug - Archive of obsolete content
1 debug.ms_async_op_status_canceled the asynchronous operation was canceled. 2 debug.ms_async_op_status_error the asynchronous operation resulted in an error. 3 properties debug.debuggerenabled determines whether debugging is enabled for the script context. debugging may be enabled or disabled whether or not a debugger is attached. debug.setnonusercodeexceptions determines whether any try-catch blocks in this scope are to be treated by the debugger as user-unhandled. functions debug.mstraceasynccallbackcompleted indicates that the callback stack associated with a previously specified asynchronous operation has completed. debug.mstraceasynccallbackstarting associates the callback stack with a previously specified asynchronous operation. debug.m...

Error.number - Archive of obsolete content
ameters object any instance of the error object. errornumber an integer representing an error. remarks an error number is a 32-bit value. the upper 16-bit word is the facility code, and the lower word is the error code. to determine the error code, use the & (bitwise and) operator to combine the number property with the hexadecimal number 0xffff. example the following example causes an exception to be thrown and displays the error code that is derived from the error number. try { // cause an error. var x = y; } catch(e) { document.write ("error code: "); document.write (e.number & 0xffff) document.write ("<br />"); document.write ("facility code: ") document.write(e.number>>16 & 0x1fff) document.write ("<br />"); document.write ("error m...

New in JavaScript 1.4 - Archive of obsolete content
the following is a changelog for javascript 1.4, which was only used for netscape's server side javascript released in 1999. the old netscape documentation can be found on archive.org. ...

New in JavaScript 1.5 - Archive of obsolete content
3 (from december 1999). new features in javascript 1.5 number.prototype.toexponential() number.prototype.tofixed() number.prototype.toprecision() const is now a reserved word. multiple catch clauses in a try...catch statement are supported. javascript authors can now add getters and setters to their objects. changed functionality in javascript 1.5 runtime errors are now reported as exceptions. regular expression changes: quantifiers — +, *, ? and {} — can now be followed by a ? to force them to be non-greedy. non-capturing parentheses, (?:x) can be used instead of capturing parentheses, (x). when non-capturing parentheses are used, matched subexpressions are not available as back-references. positive and negative lookahead assertions are supported. both assert a matc...

Reflect.enumerate() - Archive of obsolete content
lect.enumerate() method used to return an iterator with the enumerable own and inherited properties of the target object, but has been removed in ecmascript 2016 and is deprecated in browsers. syntax reflect.enumerate(target) parameters target the target object on which to get the property. return value an iterator with the enumerable own and inherited properties of the target object. exceptions a typeerror, if target is not an object. description the reflect.enumerate method returns an iterator with the enumerable own and inherited properties of the target object. examples using reflect.enumerate() var obj = { x: 1, y: 2 }; for (var name of reflect.enumerate(obj)) { console.log(name); } // logs "x" and "y" specifications not part of any standard. ...

JavaArray - Archive of obsolete content
summary core object a wrapped java array accessed from within javascript code is a member of the type javaarray. created by any java method which returns an array. in addition, you can create a javaarray with an arbitrary data type using the newinstance method of the array class: public static object newinstance(class componenttype, int length) throws negativearraysizeexception description the javaarray object is an instance of a java array that is created in or passed to javascript. javaarray is a wrapper for the instance; all references to the array instance are made through the javaarray. in javascript 1.4 and later, the componenttype parameter is either a javaclass object representing the type of the array or class object, such as one returned by java.lang.class.forname. in java...

JavaPackage - Archive of obsolete content
ackages.javapackage javapackageis the name of the object's java package. if the package is in the java, netscape, or sun packages, the packages keyword is optional. description in java, a package is a collection of java classes or other java packages. for example, the netscape package contains the package netscape.javascript; the netscape.javascript package contains the classes jsobject and jsexception. in javascript, a javapackage is a reference to a java package. for example, a reference to netscape is a javapackage. netscape.javascript is both a javapackage and a property of the netscape javapackage. a javaclass object is a reference to one of the classes in a package, such as netscape.javascript.jsobject. the javapackage and javaclass hierarchy reflect the java package and class hierarchy...

Old Proxy API - Archive of obsolete content
after a call to fix(), the proxy becomes a regular (non-proxy) object with the properties listed in the return value. the handler is no longer used. moreover, the respective method (freeze(), seal(), or preventextension()) is immediately called on the fixed object. note: the fixed object has the same object identity as the proxy object. if fix() returns undefined, the call throws a typeerror exception. derived traps default implementation refers to the code that is called for that trap when the trap isn't explicitly defined. in these functions, this refers to the handler object. emulated javascript code handler method default implementation description name in proxy has: function(name) -> boolean function(name) { return !!this.getpropertyde...

XForms Custom Controls - Archive of obsolete content
ndicate to a submit element that it needs to disable/enable due to the beginning/ending of the submission process. currently it has no meaning outside of this context. focus() is used by the processor to tell the control that it is getting focus through one of a variety of ways (i.e. through xf:setfocus action) and that the control needs to ensure that the proper widget is given focus. with rare exception, your control should only need to implement the nsixformsuiwidget interface. but certain xforms controls need to implement additional interfaces. such elements include upload and case. nsixformsaccessors the nsixformsaccessors interface allows access to the value and the state of the instance node that the control is bound to (see extensions/xforms/nsixformsaccessors.idl). currently interface is:...

Troubleshooting XForms Forms - Archive of obsolete content
are using the noscript plugin you may notice that your put and/or post requests are being converted to get requests. in order to fix this, go to the noscript options dialog (right-click on the 's' icon on the status bar and select 'options...') and select the advanced tab. the xss sub-tab has the following options: turn cross-site post requests into data-less get requests anti-xss protection exceptions you can temporarily fix the problem by unchecking the turn cross-site post requests into data-less get requests check box. alternatively, for a long term fix you can enter an exception pattern in the anti-xss protection exceptions text area. if you are developing on your local machine using apache tomcat for example then add the following regular expression on a new line: ^http://localhost:8080...

Using the Right Markup to Invoke Plugins - Archive of obsolete content
he object element is supported for use with the microsoft® windows media player. only the windows media player is supported as an activex control in netscape 7.1. the details are covered in another article. browsers such as netscape 7 will not render the flash plugin if the above kind of markup is used, because netscape 7 does not support activex or activex-based component invocations, with the exception of windows media player in netscape 7.1. mozilla-based browsers support the netscape plugin architecture, which is not com based like activex (and thus, not invoked via a unique identifier) but rather, mime type based. mozilla-based browsers support the use of the object element along with a mime type. here is an example of this usage, once again for the macromedia flash plugin: <object type="ap...

XQuery - Archive of obsolete content
being open source), but now some problems may exist with bdbxml (unlike saxon). a simple usage example is available. notes for developers wishing to access xquery in their own extensions at present, the extension works simply by using liveconnect to work with berkeley db xml's java api (and via a java wrapper class which circumvents liveconnect's current inability to handle some types of java exceptions properly). however, use of the approach of the java firefox extension might be used to turn the above extension concept into an xpcom component (giving it access to all open windows), and for berkeley db xml, possibly implementing it in c++ instead, which is that database's original language of development. however, the extension demonstrates a technique which does not depend on using xpcom, w...

Using the DOM File API in chrome code - Extensions
get one bonus feature: you can create file objects specifying the path of the file on the user's computer. this only works from privileged code, so web content can't do it. this protects users from the inherent security risks associated with allowing web content free access to the contents of their disks. if you pass a path to the file constructor from unprivileged code (such as web content), an exception will be thrown. scope availability in the jsm scope file is available without needing to do anything special. in bootstrap scope, this must be imported in like so: cu.importglobalproperties( [ "file" ] ) accessing a file by hard-coded pathname to reference a file by its path, you can simply use a string literal: var file = file.createfromfilename("path/to/some/file"); cross platform note...

Audio for Web games - Game development
htmlmediaelement api, but it becomes much easier and more flexible with the more advanced web audio api. let's look at this next. element and associated htmlmediaelement api, but it becomes much easier and more flexible with the more advanced web audio api. let's look at this next. web audio api for games the web audio api is supported across all modern desktop and mobile browsers, with the exception of opera mini. with that in mind, it's an acceptable approach for many situations to use the web audio api (see the can i use web audio api page for more on browser compatibility). the web audio api is an advanced audio javascript api that is ideal for game audio. developers can generate audio and manipulate audio samples as well as positioning sound in 3d game space. a feasible cross-browser st...

Base64 - MDN Web Docs Glossary: Definitions of Web-related terms
decoding and encoding base64 strings: btoa(): creates a base-64 encoded ascii string from a "string" of binary data ("btoa" should be read as "binary to ascii"). atob(): decodes a base64 encoded string("atob" should be read as "ascii to binary"). the algorithm used by atob() and btoa() is specified in rfc 4648, section 4. note that btoa() expects to be passed binary data, and will throw an exception if the given string contains any characters whose utf-16 representation occupies more than one byte. for more details, see the documentation for btoa(). encoded size increase each base64 digit represents exactly 6 bits of data. so, three 8-bits bytes of the input string/binary file (3×8 bits = 24 bits) can be represented by four 6-bit base64 digits (4×6 = 24 bits). this means that the base64...

Hoisting - MDN Web Docs Glossary: Definitions of Web-related terms
zations. if a variable is declared and initialized after using it, the value will be undefined. for example: console.log(num); // returns undefined, as only declaration was hoisted, no initialization has happened at this stage var num; // declaration num = 6; // initialization the example below only has initialization. no hoisting happens so trying to read the variable results in referenceerror exception. console.log(num); // throws referenceerror exception num = 6; // initialization below are more examples demonstrating hoisting. // example 1 // only y is hoisted x = 1; // initialize x, and if not already declared, declare it - but no hoisting as there is no var in the statement. console.log(x + " " + y); // '1 undefined' // this prints value of y as undefined as javascript only hoists decla...

Localization - MDN Web Docs Glossary: Definitions of Web-related terms
10,000.00 in the u.s.) date format currency cultural references paper size color psychology compliance with local laws local holidays personal names learn more general knowledge localization at mozilla on mdn localization on wikipedia ...

Signature (functions) - MDN Web Docs Glossary: Definitions of Web-related terms
in depth signatures in javascript javascript is a loosely typed or a dynamic language. that means you don't have to declare the type of a variable ahead of time. ...

Syntax error - MDN Web Docs Glossary: Definitions of Web-related terms
syntax errors are detected while compiling or parsing source code. for example, if you leave off a closing brace (}) when defining a javascript function, you trigger a syntax error. browser development tools display javascript and css syntax errors in the console. ...

MDN Web Docs Glossary: Definitions of Web-related terms
layer security) dtmf (dual-tone multi-frequency signaling) dynamic programming language dynamic typing e ecma ecmascript effective connection type element empty element encapsulation encryption endianness engine entity entity header event exception expando f fallback alignment falsy favicon fetch directive fetch metadata request header firefox os firewall first contentful paint first cpu idle first input delay first interactive first meaningful paint first paint first-class function ...

Mobile accessibility - Learn web development
days, mobile devices can usually handle fully-featured websites, and the main platforms even have screenreaders built in to enable visually impaired users to use them successfully. modern mobile browsers tend to have good support for wai-aria, too. to make a website accessible and usable on mobile, you just need to follow general good web design and accessibility best practices. there are some exceptions that need special consideration for mobile; the main ones are: control mechanisms — make sure interface controls such as buttons are accessible on mobiles (i.e., mainly touchscreen), as well as desktops/laptops (mainly mouse/keyboard). user input — make user input requirements as painless as possible on mobile (e.g., in forms, keep typing to a minimum). responsive design — make sure l...

Organizing your CSS - Learn web development
same rules to something outside of main, or to something other than a <p>, you would have to add another selector to these rules or create a whole new ruleset. instead, you could use the selector .box to apply your rule to any element that has the class box: .box { border: 1px solid #ccc; } there will be times when making something more specific makes sense, however this will generally be an exception rather than usual practice. break large stylesheets into multiple smaller ones in particular in cases where you have very different styles for distinct parts of the site, you might want to have a stylesheet that includes all the global rules and then smaller ones that include the specific rules needed for those sections. you can link to multiple stylesheets from one page, and the normal rules o...

What do common web layouts contain? - Learn web development
rt mixing them all together: … these are just examples and you're quite free to lay things out as you want. you may notice that, while the content can move around on the screen, we always keep the header (1) on top and the footer (2) at the bottom. also, the main content (a) matters most, so give it most of the space. these are rules of thumb you can draw on. there are complex designs and exceptions, of course. in other articles we'll discuss how to design responsive sites (sites that change depending on the screen size) and sites whose layouts vary between pages. for now, it's best to keep your layout consistent throughout your site. active learning there is no active learning available yet. deeper dive let's study some more concrete examples taken from well-known websites. one-column...

The HTML5 input types - Learn web development
in html5 to allow collection of specific types of data. prerequisites: basic computer literacy, and a basic understanding of html. objective: to understand the newer input type values available to create native form controls, and how to implement them using html. note: most of the features discussed in this article have wide support across browsers. we'll note any exceptions. if you want more detail on browser support, you should consult our html forms element reference, and in particular our extensive <input> types reference. because html form control appearance may be quite different from a designer's specifications, web developers sometimes build their own custom form controls. we cover this in an advanced tutorial: how to build custom form widgets. e-mail add...

Sending form data - Learn web development
le out, to get an idea of what's possible. be paranoid: never trust your users so, how do you fight these threats? this is a topic far beyond this guide, but there are a few rules to keep in mind. the most important rule is: never ever trust your users, including yourself; even a trusted user could have been hijacked. all data that comes to your server must be checked and sanitized. always. no exception. escape potentially dangerous characters. the specific characters you should be cautious with vary depending on the context in which the data is used and the server platform you employ, but all server-side languages have functions for this. things to watch out for are character sequences that look like executable code (such as javascript or sql commands). limit the incoming amount of data to ...

Styling web forms - Learn web development
<textarea>, <input type="submit">, and a <button> in chrome on macos, with the platform's default font style in use. on the right are the same elements, with our above style rule applied. the defaults differed in a number of ways. inheriting should change their fonts to that of the parent's font family — in this case the default serif font of the parent container. they all do, with a strange exception — <input type="submit"> does not inherit from the parent paragraph in chrome. rather, it uses the font-family: system-ui. this is another reason to use <button> elements over their equivalent input types! there's a lot of debate as to whether forms look better using the system default styles, or customized styles designed to match your content. this decision is yours to make, as the designer o...

Document and website structure - Learn web development
ifferent pages. this is very similar to a technique called card sorting. now try to sketch a rough sitemap — have a bubble for each page on your site, and draw lines to show the typical workflow between pages. the homepage will probably be in the center, and link to most if not all of the others; most of the pages in a small site should be available from the main navigation, although there are exceptions. you might also want to include notes about how things might be presented. active learning: create your own sitemap try carrying out the above exercise for a website of your own creation. what would you like to make a site about? note: save your work somewhere; you might need it later on. test your skills! you've reached the end of this article, but can you remember the most important in...

Marking up a letter - Learn web development
to be hosted on a university intranet. the letter is a response from a research fellow to a prospective phd student concerning their application to the university. block/structural semantics use appropriate document structure including doctype, and <html>, <head> and <body> elements. in general, the letter should be marked up as an organization of headings and paragraphs, with the following exception. there is one top level heading (the "re:" line) and three second level headings. use an appropriate list type to mark up the semester start dates, study subjects, and exotic dances. put the two addresses inside <address> elements. each line of the address should sit on a new line, but not be in a new paragraph. inline semantics the names of the sender and receiver (and tel and email) shou...

Fetching data from the server - Learn web development
text(), to get it to pass its result on to the next link in the chain. which mechanism should you use? this really depends on what project you are working on. xhr has been around for a long time now and has very good cross-browser support. fetch and promises, on the other hand, are a more recent addition to the web platform, although they're supported well across the browser landscape, with the exception of internet explorer. if you need to support older browsers, then an xhr solution might be preferable. if however you are working on a more progressive project and aren't as worried about older browsers, then fetch could be a good choice. you should really learn both — fetch will become more popular as internet explorer declines in usage (ie is no longer being developed, in favor of microsoft...

Introduction to the server side - Learn web development
with html templates (4), and sends back a response containing the generated html (5,6). are server-side and client-side programming the same? let's now turn our attention to the code involved in server-side and client-side programming. in each case, the code is significantly different: they have different purposes and concerns. they generally don't use the same programming languages (the exception being javascript, which can be used on the server- and client-side). they run inside different operating system environments. code running in the browser is known as client-side code and is primarily concerned with improving the appearance and behavior of a rendered web page. this includes selecting and styling ui components, creating layouts, navigation, form validation, etc. by contrast, ser...

TypeScript support in Svelte - Learn web development
r { all = 'all', active = 'active', completed = 'completed', } now we will use this from the filterbutton component. ...

Componentizing our Svelte app - Learn web development
tracting our filter component we'll begin by creating our filterbutton.svelte. first of all, create a new file — components/filterbutton.svelte. inside this file we will declare a filter prop, and then copy the relevant markup over to it from todos.svelte. ...

Dynamic behavior in Svelte: working with variables and props - Learn web development
d update the list of todos. let's see how to achieve this. the filtertodos() function will receive the current filter and the list of todos, and return a new array of todos filtered accordingly. let's update the filter button markup to make it dynamic and update the current filter when the user presses one of the filter buttons. ...

Getting started with Vue - Learn web development
used in development code into older syntax that is more cross-browser compatible in production code. you can register additional babel plugins in this file. .browserslistrc: this is a config for browserslist. you can use this to control which browsers your tooling optimizes for. public: this directory contains static assets that are published, but not processed by webpack during build (with one exception; index.html gets some processing). favicon.ico: this is the favicon for your app. currently, it's the vue logo. index.html: this is the template for your app. your vue app is run from this html page, and you can use lodash template syntax to interpolate values into it. note: this is not the template for managing the layout of your application — this template is for managing static ...

Setting up your own test automation environment - Learn web development
output of your test will be reflected on your lambdatest console. if you wish to extract these results for reporting purpose from lambdatest platform then you can do so by using lambdatest restful api. now if you go to your lambdatest automation dashboard, you'll see your test listed; from here you'll be able to see videos, screenshots, and other such data. you can retrieve network, command, exception, and selenium logs for every test within your test build. you will also find a video recording of your selenium script execution. note: the help button on lambdatest automation dashboard will provide you with an ample amount of information to help you get started with lambdatest automation. you can also follow our documentation about running first selenium script in node js. note: if you d...

Chrome Worker Modules
and cannot be used for the installation of resources, please see the documentation on moz.build (if your code is part of the platform) or on chrome manifests (if your code is part of an add-on). stack traces unfortunately, the module loader doesn’t play nicely with error stack traces. that is, the following will not show human-readable stacks: try { mymodule.foo(); } catch (ex) { log("exception raised at " + ex.filename) log("stack: " + ex.stack); } rather, you should use properties modulename and modulestack, as follows: try { mymodule.foo(); } catch (ex) { log("exception raised at " + ex.modulename) log("stack: " + ex.modulestack); } subtleties you shouldn’t mix both styles exports.foo = bar and module.exports = {foo: bar}. if you do, know that any call to module...

Mozilla accessibility architecture
rovider::getaccessible() or nsiframe::getaccessible(), new accessibles are created by calling back to the accessibility service, and using a specific method for creating each type of accessible. for example, nshtmltablecellframe::getaccessible() will eventually call nsiaccessibilityservice::createhtmltablecellaccessible(), which uses |new nshtmltablecellaccessible(domnode, weakpresshell); special exception: traversal overloading in some cases the necessary accessible children are not in the dom subtree for a node. this is the case for: nshtmlimageaccessible: in msaa an image accessible can have accessible children if it has an image map. the children are the image map areas, which are in a different part of the dom tree. nshtmlcomboboxaccessible: an html combo box doesn't have a dom node or an...

Browser chrome tests
really do that instead! function test() { // requestlongertimeout accepts an integer factor, that is a multiplier for the the default 30 seconds timeout. // so a factor of 2 means: "wait for at last 60s (2*30s)". requestlongertimeout(2); waitforexplicitfinish(); settimeout(completetest, 40000); } function completetest() { ok(true, "timeout did not run"); finish(); } exceptions in tests any exceptions thrown under test() will be caught and reported in the test output as a failure. exceptions thrown outside of test() (e.g. in a timeout, event handler, etc) will not be caught, but will result in a timed out test if they prevent finish() from being called. cleaning up after yourself if you need to do special clean up after running your test, you can register a cleanup ...

Creating Sandboxed HTTP Connections
k onchannelredirect: function (aoldchannel, anewchannel, aflags) { // if redirecting, store the new channel gchannel = anewchannel; }, // nsiinterfacerequestor getinterface: function (aiid) { try { return this.queryinterface(aiid); } catch (e) { throw components.results.ns_nointerface; } }, // nsiprogresseventsink (not implementing will cause annoying exceptions) onprogress : function (arequest, acontext, aprogress, aprogressmax) { }, onstatus : function (arequest, acontext, astatus, astatusarg) { }, // nsihttpeventsink (not implementing will cause annoying exceptions) onredirect : function (aoldchannel, anewchannel) { }, // we are faking an xpcom interface, so we need to implement qi queryinterface : function(aiid) { if (aiid.equals(c...

Eclipse CDT
arch for unresolved includes". for problematic source files, select the file in the project explorer and from the context menu select "index > create parser log file". select your project in the project explorer, then from the context menu select "index > rebuild". when the indexing is done, open the log using "window > show view > other > general > error log" and check the summary and look for exceptions. searching free text search is not backed by a database, so it is extremely slow. furthermore, the results are not saved so if you immediately search for the exact same text again without any changes to the source files having occurred, eclipse will do a slow search all over again. it is not easy to restrict searches to an arbitrary directory, which is pretty annoying given how slow free tex...

Interface Compatibility
rogramming interfaces change. the rules which govern interface changes are different depending on the consumers and the languages involved. web content apis which are visible to web content are not modified, except as a last resort when inherent security vulnerabilities or incompatibility with other browsers make it the only option. any changes, including new features, must have super-review. one exception to this rule is apis which are explicitly shipped with mozilla prefixes as a technology preview. this includes css properties that begin with the -moz- prefix (e.g. -moz-box-shadow), or javascript apis that begin with the moz prefix (e.g. canvasrenderingcontext.mozdrawtext). these apis may be removed or replaced with standard interfaces in future releases of mozilla. jetpack the jetpack sdk and...

Commenting IDL for better documentation
monster. * @param cookietoeat the nsicookie to eat. */ void eatcookie(in nsicookie cookietoeat); /** * sings the song "c is for cookie." */ void sing(); /** * returns a string containing a funny quote the cookie monster might say. * * @param number the saying number to return. * * @returns an astring containing the requested funny quote. if the specified * quote number is invalid, an exception is thrown. * * @throws ns_error_failure unable to locate the requested quote. */ astring getfunnysaying(in integer number); /** * says something appreciative of the tastiness of the cookie in the specified * language. * * @param language the localization identification indicating the language in * which the cookie monster is to express his love of cookies. */ [noscript] void sayyummy(in...

Reviewer Checklist
up to make the fix easier to write and review". if qa needs to verify the fix, you should provide steps to reproduce (str). quality if you can unit-test it, you should unit-test it. if it's js, try to design and build so that xpcshell can exercise most functionality. it's quicker. make sure the patch doesn't create any unused code (e.g., remove strings when removing a feature) all caught exceptions should be logged at the appropriate level, bearing in mind personally identifiable information, but also considering the expense of computing and recording log output. [fennec: checking for log levels is expensive unless you're using logger.] style follow the style guide for the language and module in question. follow local style for the surrounding code, even if that local style isn't for...

Error codes returned by Mozilla APIs
rror_xpc_scriptable_ctor_failed (0x80570012) ns_error_xpc_cant_call_wo_scriptable (0x80570013) ns_error_xpc_cant_ctor_wo_scriptable (0x80570014) ns_error_xpc_ci_returned_failure (0x80570015) ns_error_xpc_gs_returned_failure (0x80570016) ns_error_xpc_bad_cid (0x80570017) ns_error_xpc_bad_iid (0x80570018) ns_error_xpc_cant_create_wn (0x80570019) ns_error_xpc_js_threw_exception (0x8057001a) ns_error_xpc_js_threw_native_object (0x8057001b) ns_error_xpc_js_threw_js_object (0x8057001c) ns_error_xpc_js_threw_null (0x8057001d) ns_error_xpc_js_threw_string (0x8057001e) ns_error_xpc_js_threw_number (0x8057001f) ns_error_xpc_javascript_error (0x80570020) ns_error_xpc_javascript_error_with_details (0x80570021) ns_error_xpc_cant_convert_primitive_t...

Cross Process Object Wrappers
this document describes cross process object wrappers (cpows), which enable chrome code to synchronously access content in multiprocess firefox. note that from firefox 47 onwards, unsafe cpow usage is no longer permitted in browser code. if browser code tries an unsafe cpow operation, the browser will throw an exception and you'll see an "unsafe cpow usage forbidden” error in the browser console. add-on code is still allowed to use cpows "unsafely". however, if an add-on passes a cpow into a platform api, and that platform api then attempts an unsafe operation on it, this will throw an exception. so as a general rule, add-ons should avoid passing cpows into non-addon code. in multiprocess firefox, chrome code runs in a different process from web content. so chrome code can't direct...

Limitations of chrome scripts
ager. limitations of cpows cross process object wrappers (cpows) are a migration aid giving chrome code synchronous access to content objects. however, there are various limitations on the kinds of things you can do with a cpow. note that from firefox 47 onwards, unsafe cpow usage is no longer permitted in browser code. if browser code tries an unsafe cpow operation, the browser will throw an exception and you'll see an "unsafe cpow usage forbidden” error in the browser console. add-on code is still allowed to use cpows "unsafely". however, if an add-on passes a cpow into a platform api, and that platform api then attempts an unsafe operation on it, this will throw an exception. so as a general rule, add-ons should avoid passing cpows into non-addon code. nsicontentpolicy without the shim...

Limitations of frame scripts
ntent process. for example: nsisessionstore nsiwindowmediator <need more examples> places api the places api can't be used inside a frame script. for example: nsinavhistoryservice nsinavbookmarksservice observers in the content process as noted in observers in the chrome process, most observers should be registered in the chrome process and will not work in the content process. the exceptions are: content-document-global-created document-element-inserted outer-window-destroyed inner-window-destroyed dom-window-destroyed these must be registered in the content process. qi from content window to chrome window there's a particular pattern often used to get from a content window to the associated chrome window. it looks something like this: window.queryinterface(ci.nsiinte...

Communicating with frame scripts
this is an intentional design decision made to prevent content code from making chrome code unresponsive. ...

Limitations of frame scripts
ntent process. for example: nsisessionstore nsiwindowmediator <need more examples> places api the places api can't be used inside a frame script. for example: nsinavhistoryservice nsinavbookmarksservice observers in the content process as noted in observers in the chrome process, most observers should be registered in the chrome process and will not work in the content process. the exceptions are: content-document-global-created document-element-inserted outer-window-destroyed inner-window-destroyed dom-window-destroyed these must be registered in the content process. qi from content window to chrome window there's a particular pattern often used to get from a content window to the associated chrome window. it looks something like this: window.queryinterface(ci.nsiinte...

Performance
all the previous examples, *even the "better" ones* if your addon is restartless or uses the sdk then updates or the user turning it off and on will load to unload/reload events. not handling those properly can lead to duplicate or conflicting code execution, especially when messages are sent. it can also lead to conflicts between the old and new code. under some circumstances it may even cause exceptions when attempting to register something twice under the same id. better: // addon.js function onunload() { services.mm.removedelayedframescript("resources://my-addon/framescript.js"); services.ppmm.removedelayedprocessscript("resources://my-addon/processcript.js"); services.mm.broadcastasyncmessage("my-addon:unload"); services.ppmm.broadcastasyncmessage("my-addon:unload"); } in the fra...

Blocked: Custom cookie permission
quest to access cookies or storage on “x” was blocked because of custom cookie permission. what went wrong? a request to access cookies or storage was blocked because there's a custom user-defined permission set. the permission can be changed or removed by: going to preferences > content blocking > cookies and site data clicking on the manage permissions button and updating the listed exceptions ...

Blocked: All third-party storage access requests
r storage on “x” was blocked because we are blocking all third-party storage access requests and content blocking is enabled. what went wrong? a request to access cookies or storage was blocked because it came from a third-party (a different origin) and content blocking is enabled. the permission can be changed or removed by: going to preferences > content blocking and either adding an exception with the manage exceptions… button choosing the custom content blocking and unchecking the cookies checkbox if the resource that is being blocked doesn't need authentication, you can fix the warning message by adding a crossorigin="anonymous" attribute to the relevant element. ...

Blocked: Storage access requests from trackers
est to access cookies or storage on “x” was blocked because it came from a tracker and content blocking is enabled. what went wrong? a request to access cookies or storage was blocked because the browser identified it as coming from a tracker and content blocking is enabled. the permission can be changed or removed by: going to preferences > content blocking and either adding an exception with the manage exceptions… button choosing the custom content blocking and unchecking the tracker checkbox if the blocked resource doesn't need authentication, you can fix the warning message by adding a crossorigin="anonymous" attribute to the relevant element. ...

Security best practices for Firefox front-end engineers
anonical truth for the list of whitelisted elements is the source code. the last flag ensures that developers will identify and avoid the problems early on in the development cycle and before shipping the code. linter rules against unsanitized dom interaction the security assurance team maintains an eslint rule that disallows unsafe uses of innerhtml and similar dom apis. the linter makes an exception for code that uses string literals that are hard coded in the source code, assuming benevolent developers. developers are able to avoid tripping the rule by using escaping functions in combination with template strings, for example: bar.innerhtml = escapehtml`<a href='${url}'>about</a>`; in system-privileged chrome code, any kind of remaining scripts will still be removed by our sanitizer. ...

CSS <display-xul> component
see this firefox site compatibility post for more details. the -moz-box and -moz-inline-box values will be removed later in bug 879275. see this firefox site compatibility post for more details. ...

How to get a stacktrace with WinDbg
a. producing a minidump sometimes the stacktrace alone is not enough information for a developer to figure out what went wrong. a developer may ask you for a "minidump" or a "full memory dump", which are files containing more information about the process. you can easily produce minidumps from windbg and provide them to developers. faq q: i am running windows 7 (32-bit or 64-bit) and i see an exception in the windbg command window that says 'ntdll32!ldrpdodebuggerbreak+0x2c' or 'ntdll32!ldrpdodebuggerbreak+0x30'. what do i do now? a: if you see 'int 3' after either of those exceptions, you will need to execute the following commands in windbg. bp ntdll!ldrpdodebuggerbreak+0x30 bp ntdll!ldrpdodebuggerbreak+0x2c eb ntdll!ldrpdodebuggerbreak+0x30 0x90 eb ntdll!ldrpdodebuggerbreak+0x2c 0x90 mak...

Implementing Download Resuming
annel interface. the expected way to use it is this: for all downloads that happen, get the entityid from the channel, and store it for later use. the entity id is what ensures that the file remains unchanged. this can also be used to check whether the download is resumable: if it is not (e.g. the server is not using http 1.1), then accessing this attribute will throw an ns_error_not_resumable exception. if the download gets interrupted, necko will call the stream listener's onstoprequest method with a failure status. (todo: document what webbrowserpersist/exthandler do). the front-end code can then notify the user of this, and offer to resume the download. resuming a download in order to resume a download, you should create a channel as usual (using nsiioservice). then, you can check if it ...

AsyncShutdown.jsm
managing safe shutdown of asynchronous services. firefox shutdown is composed of phases that take place sequentially. typically, each shutdown phase removes some capabilities from the application. for instance, at the end of phase profilebeforechange, no service is permitted to write to the profile directory (with the exception of telemetry). consequently, if any service has requested i/o to the profile directory before or during phase profilebeforechange, the system must be informed that these requests need to be completed before the end of phase profilebeforechange. failing to inform the system of this requirement can (and has been known to) cause data loss. example at some point during shutdown, the add-on manager needs to ensure that all add-ons have safely written their data to disk...

DeferredTask.jsm
sk cannot be re-entered while running, but can be executed again after a previous run finished. a common use case occurs when a data structure should be saved into a file every time the data changes, using asynchronous calls, and multiple changes to the data may happen within a short time: let savedeferredtask = new deferredtask(function* () { yield os.file.writeatomic(...); // any uncaught exception will be reported. }, 2000); // the task is ready, but will not be executed until requested. the "arm" method can be used to start the internal timer that will result in the eventual execution of the task. multiple attempts to arm the timer don't introduce further delays: savedeferredtask.arm(); // the task will be executed in 2 seconds from now. yield waitonesecond(); savedeferredtask.arm()...

Downloads.jsm
rk on downloads that were not started from a private browsing window. private work on downloads that were started from a private browsing window. all work on both downloads.private and downloads.public downloads. properties attribute type description error read only constructor constructor for a downloaderror object. when you catch an exception during a download, you can use this to verify if ex instanceof downloads.error, before reading the exception properties with the error details. example (using task.jsm): try { yield downloads.fetch(sourceuri, targetfile); } catch (ex if ex instanceof downloads.error && ex.becausetargetfailed) { console.log("unable to write to the target file, ignoring the error."); } methods ...

OS.File.Error
ile.error, setting the platform-specific error number. error closed() error exists() methods os.file.error.closed() return an error representing the fact that a file is closed. os.file.error.exists() return an error representing the fact that a file exists. instances of os.file.error in case of any i/o error, the functions of os.file raise instances of os.file.error. these exceptions hold both a human-readable error message detailing the i/o error and attributes to help determining the cause of the error. cross-platform attributes operation the human-readable name of the failed operation. becauseexists true if the operation failed because a file or directory exists, false otherwise. becausenosuchfile true if the operation failed because a ...

PerfMeasurement.jsm
nces uint64 the number of memory accesses that occurred. cache_misses uint64 the number of times memory accesses missed the cache. branch_instructions uint64 the number of branch instructions executed. branch_misses uint64 the number of times branch prediction guessed wrong. bus_cycles uint64 the number of memory bus cycles that elapsed. page_faults uint64 the number of page exceptions the os handled. major_page_faults uint64 the number of times page faults required disk access. context_switches uint64 the number of context switches that occurred involving the thread being profiled. cpu_migrations uint64 the number of times the profiled thread migrated from one cpu core to another. event types measured constant the eventsmeasured constant provides a mask indicat...

Deferred
either to a value, a rejection, or another promise, this method does nothing. note: this function is bound to its associated promise when promise.defer() is called, and can be called with any value of this. void reject( areason ); parameters areason optional the rejection reason for the associated promise. although the reason can be undefined, it is generally an error object, like in exception handling. note: this argument should not be a promise. specifying a rejected promise would make the rejection reason equal to the rejected promise itself, and not its rejection reason. backwards and forwards compatible helper this deferred function can be used for backwards and forwards compatibility, due to a change that took place in firefox 30. function deferred() { // update 062115 f...

Deferred
resolved, either to a value, a rejection, or another promise, this method does nothing. note: this function is exactly same as promise constructor's reject argument, and can be called with any value of this. void reject( areason ); parameters areason optional the rejection reason for the associated promise. although the reason can be undefined, it is generally an error object, like in exception handling. note: this argument should not be a promise. specifying a rejected promise would make the rejection reason equal to the rejected promise itself, and not its rejection reason. ...

Sqlite.jsm
sive memory usage. therefore, it's recommended to use onrow with select statements. along with a result row, onrow is passed a cancel function as its second argument. consumers of this api can call the cancel function should they want to immediately abort the execution of the statement. when cancelled, subsequent rows will not be processed and no more onrow invocations will be made. if an exception is thrown by the onrow handler, the exception is logged and processing of subsequent rows occurs as if nothing happened. the promise is still resolved (not rejected). the return promise will be rejected with an error instance if the statement did not finish execution fully. the error may have an errors property. if defined, it will be an array of objects describing individual errors. each object...

XPCOMUtils.jsm
function generateci( classinfo ); parameters classinfo an object containing the optional properties interfaces, contractid, classdescription, classid, flags. this parameter should not be the component itself because that would cause a memory leak. return value an nsiclassinfo implementation returning the values of the properties from the classinfo parameter in its various properties. exceptions thrown this method throws an exception with the message "in generateci, don't use a component for generating classinfo" if classinfo parameter is an xpcom component. generateqi() generates a queryinterface() function implementation. you need to assign the returned function to the queryinterface property of a javascript object. when the generated method is invoked on that object, it checks to...

Encodings for localization files
installer the windows installer can’t handle utf-8, but only the codepages provided by windows. ...

Mozilla Content Localized in Your Language
second. percentages how are percentages expressed in your language? digit groups how are digit groups expressed in your language? example: 1.23 (decimal separator) or 1,000 (thousand separator) using comma or period. acronyms do you translate widely accepted acronyms such as cd, dvd, mb? if translated, is there an equavilent acronym and widely accepted in the language? gender are there exceptions to standard gender conventions within your language? if so, what are they? tone/register what is the appropriate tone for your translations? does it vary by product and target audience? if so, how? what are formality to avoid? list products and their tones if different. capitalization what is the appropriate form of expressing capitalization in your language? note: if this doens't apply, ho...

Localizing with Mozilla Translator
stance, '''toolkit/locales/chrome''' in mozilla-central matches '''locale/en-us''' and '''browser/locales/chrome''' matches '''locale/browser'''. so, what you have to do is export partial glossaries in each link point of the ''old'' product and import them in the corresponding link point of the ''new'' point. your keep original and fuzzy flags will be honored for each string. there will be some exceptions. files hanging directly from the platform neutral platform can't be part of a partial glossary (because they are not components), and platform neutral itself can't be selected either, since it is not a component, but a platform. for these few files, you will have to export them individually and reimport them. if you are a ''not so good'' mt user, however, you can just create a new product (or s...

What every Mozilla translator should know
of the l10n to follow up your bug you should cc: l10n@mozilla.com if you choose to make changes to your localization, you should make the changes local to your disk, push them to your hg repository on merucial, test the changes on a nightly/tinderbox build, fix any errors if some are found and test again, and send the new changeset id as your "opt-in" revisions to the l10-drivers. there is one exception to this process. if you choose to make any changes to the productization elements (i.e. search plugins, protocol handlers, rss/live bookmarks), you will need to upload a patch with the suggested changes to bugzilla and get approval before pushing those changes to your hg repository. do the changes in your local disk create a diff file with the changes $ hg diff -p -u 8 filename create a...

Writing localizable code
posite strings are often very difficult to translate. when a composite string is needed, try to give the translators "room to move". an example of a well used composite string is firefox's setting for visited pages: the translator can (implicitly) position the text field as he sees fit. don't use preprocessor macros the use of #if #else #endif or #expand is strongly discouraged. there are few exceptions to this rule, but in general, the localized file should comply with standards and should not require build tools to be transformed. if you want to add build processing to localized files, be sure to request feedback from l10n@. in most cases, you can just as well put the processing into the content code and reference different key-value pairs in l10n. use a good source directory structure be...

MathML3Testsuite
ults of the mathml 3 full testsuite for presentation mathml. the sections are marked with passed, failed, not-tested or some parts pass, giving the status of trunk builds with the appropriate fonts installed. when the markup is intentionally errorous, the correct behavior is not defined by the recommendation and hence the tests are considered passed if there is no fatal error (crash, etc). this exception also holds for obsolete features (such as macro, mode etc) or for other undefined behaviors (attribute href for example). note that in general, comparing with the "sample rendering" is not enough to conclude on the success/failure of the test. so please do not edit these pages if you are not able to explain gecko's rendering. however, any report is welcome on the tracking bug for the mathml tests...

Mozilla Port Blocking
ports enabled by protocol handlers in mozilla: protocol handler allowed ports ftp 21, 22 ldap 389, 636 nntp any port pop3 any port imap any port smtp any port finger 79 datetime 13 how...

Mozilla Web Developer FAQ
values are normalized to spaces at parse time, so the original white space never makes it to the dom. this affects data round tripping using hidden form inputs. in versions prior to gecko 1.9/firefox 3, the document is not loaded and rendered incrementally. the layout mode is the (full) standards mode regardless of doctype. css works according to the xml+css rules. html-specific css exceptions do not apply. for example, the body element gets no special treatment. css selectors are case-sensitive. the dom is in the xml mode. namespace-aware variants of methods need to be used when working with elements (eg. createelementns() instead of createelement()). element and attribute names are not normalized to upper case. other namespaces are supported. mathml ...

Activity Monitor, Battery Status Menu and top
ed on these facts it seems reasonable to assume that “energy impact” is again being used to determine which applications are "using significant energy". testing shows that once an energy-intensive application is started it takes less than a minute for it to show up in the battery status menu. and once the application stops using high amounts of energy it takes a few minutes to disappear. the exception is when the application is closed, in which case it disappears immediately. and it appears that a program with an “energy impact” of roughly 20 or more will eventually show up as significant, and programs that have much higher “energy impact” values tend to show up more quickly. all of these battery status menu observations are difficult to make reliably and so should be treated with cau...

JS::PerfMeasurement
::cache_misses .cache_misses memory accesses that missed the cache ::branch_instructions .branch_instructions branch instructions executed ::branch_misses .branch_misses branch instructions that were not predicted correctly ::bus_cycles .bus_cycles total memory bus cycles ::page_faults .page_faults total page-fault exceptions fielded by the os ::major_page_faults .major_page_faults page faults that required disk access ::context_switches .context_switches context switches involving the profiled thread ::cpu_migrations .cpu_migrations migrations of the profiled thread from one cpu core to another these events map directly to "generic events" in the linux 2.6.

Debugging out-of-memory problems
gnose with emscripten is where a big game fails due to an out of memory error (oom) somewhere during load time. by the time about:memory is loaded in a new tab and you have clicked the "measure" button to diagnose what's happened, the memory usage causing the spike has gone away, making temporary memory spikes difficult to diagnose. this article explains how to debug such problems. out-of-memory exceptions from js setting memory.dump_reports_on_oom in about:config to true will cause the browser to automatically write about:memory dumps to a temp file printed to the browser console (note: not web console) when an oom crash is encountered. for more information, see bug 969415. out-of-memory crashes in some cases, running out of memory causes the browser to crash. ideally, memory.dump_reports_on_...

NSPR's Position On Abrupt Thread Termination
events, these resources will be allocated by a thread, used for some period of time, and then freed as the stack unwinds. in these cases, the presence of the data is recorded only on the stack, known only to the single thread (normally referred to as encapsulated). the problem with abrupt termination is that it can happen at any time, to a thread that is coded correctly to handle both normal and exceptional situations, but will be unable to do so since it will be denied the opportunity to complete execution. it can happen because it called out of its own scope into some lazily implemented library. nspr's answer to this is that there is no abrupt thread termination. all threads must unwind and return from their root function. if they cannot, because of some state corruption, then they must assume t...

Optimizing Applications For NSPR
allenge that was met to a large degree, but there is always room for improvement. the casual client may not encounter a need to know the details of the shortcomings to the level described here, but if and when clients become more sophisticated, these issues will certainly surface. this memo is by no way complete. multiplatform do not call any blocking system call from a local thread. the only exception to this rule is the <tt>select()</tt> and <tt>poll()</tt> system calls on unix, both of which nspr has overridden to make sure they are aware of the nspr local threads. in the combined (mxn) model, which includes nt, irix (sprocs), and pthreads-user, the primordial thread is always a local thread. therefore, if you call a blocking system call from the primordial thread, it is going to block more...

Monitors
count it had before the wait operation. unlike a mutex of type prlock, a mutex of type prmonitor has a single, implicitly associated condition variable that may be used to facilitate synchronization of threads with the change in state of monitored data. for an introduction to nspr thread synchronization, including locks and condition variables, see introduction to nspr. monitor type with the exception of pr_newmonitor, which creates a new monitor object, all monitor functions require a pointer to an opaque object of type prmonitor. monitor functions all monitor functions are thread-safe. however, this safety does not extend to protecting the monitor object from deletion. pr_newmonitor creates a new monitor. pr_destroymonitor destroys a monitor object. pr_entermonitor enters the lock ass...

JSS Provider Notes
vernment. sun therefore requires that jar files implementing jce algorithms be digitally signed by an approved organization. netscape has this approval and signs the official builds of jss32.jar. at runtime, the jre automatically verifies this signature whenever a jss class is loaded that implements a jce algorithm. the verification is transparent to the application (unless it fails and throws an exception). if you are curious, you can verify the signature on the jar file using the jarsigner tool, which is distributed with the jdk. if you build jss yourself from source instead of using binaries downloaded from mozilla.org, your jar file will not have a valid signature. this means you will not be able to use the jss provider for jce algorithms. you have two choices. use the binary release ...

Mozilla-JSS JCA Provider notes
files implementing jce algorithms be digitally signed by an approved organization. the maintainers of jss, sun, red hat, and mozilla, have this approval and signs the official builds of jss4.jar. at runtime, the jre automatically verifies this signature whenever a jss class is loaded that implements a jce algorithm. the verification is transparent to the application (unless it fails and throws an exception). if you are curious, you can verify the signature on the jar file using the jarsigner tool, which is distributed with the jdk. if you build jss yourself from source instead of using binaries downloaded from mozilla.org, your jar file will not have a valid signature. this means you will not be able to use the jss provider for jce algorithms. you have two choices. use the binary release of jss f...

NSS 3.12.6 release notes
ification of an alternate library for sqlite bug 524167: crash in [[@ find_objects_by_template - nsstoken_findcertificatebyissuerandserialnumber] bug 526910: maxresponselength (initialized to pkix_default_max_response_length) is too small for downloading some crls. ...

NSS 3.19.2.1 release notes
issues can overflow the heap and may be able to obtain remote code execution. the following security-relevant bugs have been resolved in nspr 4.10.10, which affect nss. because nss includes portions of the affected nspr code at build time, it is necessary to use nspr 4.10.10 when building nss. bug 1205157 (nspr, cve-2015-7183): a logic bug in the handling of large allocations would allow exceptionally large allocations to be reported as successful, without actually allocating the requested memory. this may allow attackers to bypass security checks and obtain control of arbitrary memory. new in nss 3.19.2.1 new functionality no new functionality is introduced in this release. this is a patch release to fix security-relevant bugs. compatibility nss 3.19.2.1 shared libraries are backwar...

NSS 3.19.4 release notes
issues can overflow the heap and may be able to obtain remote code execution. the following security-relevant bugs have been resolved in nspr 4.10.10, which affect nss. because nss includes portions of the affected nspr code at build time, it is necessary to use nspr 4.10.10 when building nss. bug 1205157 (nspr, cve-2015-7183): a logic bug in the handling of large allocations would allow exceptionally large allocations to be reported as successful, without actually allocating the requested memory. this may allow attackers to bypass security checks and obtain control of arbitrary memory. new in nss 3.19.4 new functionality no new functionality is introduced in this release. this is a patch release to fix security-relevant bugs. compatibility nss 3.19.4 shared libraries are backward co...

NSS 3.20.1 release notes
issues can overflow the heap and may be able to obtain remote code execution. the following security-relevant bugs have been resolved in nspr 4.10.10, which affect nss. because nss includes portions of the affected nspr code at build time, it is necessary to use nspr 4.10.10 when building nss. bug 1205157 (nspr, cve-2015-7183): a logic bug in the handling of large allocations would allow exceptionally large allocations to be reported as successful, without actually allocating the requested memory. this may allow attackers to bypass security checks and obtain control of arbitrary memory. new in nss 3.20.1 new functionality no new functionality is introduced in this release. this is a patch release to fix security-relevant bugs. compatibility nss 3.20.1 shared libraries are backward co...

NSS 3.28.3 release notes
e, and will always set it to ecpoint_undefined. see bug 1340103. compatibility nss 3.28.3 shared libraries are backward compatible with most older nss 3.x shared libraries, but depending on your application, may be incompatible, if you application has been compiled against header files of versions 3.28, 3.28.1, or 3.28.2. a program linked with most older nss 3.x shared libraries (excluding the exceptions mentioned above), will work with nss 3.28.3 shared libraries without recompiling or relinking. furthermore, applications that restrict their use of nss apis to the functions listed in nss public functions will remain compatible with future versions of the nss shared libraries. if you had compiled your application against header files of nss 3.28, nss 3.28.1 or nss 3.28.2, it it recommended that...

NSS 3.29.1 release notes
branch has also been released with the identical fixes. compatibility nss 3.29.1 shared libraries are backward compatible with most older nss 3.x shared libraries, but depending on your application, may be incompatible, if you application has been compiled against header files of versions 3.28, 3.28.1, 3.28.2 nss 3.29.1. a program linked with most older nss 3.x shared libraries (excluding the exceptions mentioned above), will work with nss 3.29.1 shared libraries without recompiling or relinking. furthermore, applications that restrict their use of nss apis to the functions listed in nss public functions will remain compatible with future versions of the nss shared libraries. if you had compiled your application against header files of nss 3.28, nss 3.28.1, nss 3.28.2 or nss 3.29, it it recomm...

NSS Developer Tutorial
ide, list c++ features that are known to be widely available and compatible. you should limit features to those that appear in both guides. ask on nss-dev@ if you think this is restrictive, or if you wish to prohibit a specific feature. nss c abi backward compatibility functions exported functions cannot be removed. the function prototype of an exported function, cannot be changed, with these exceptions: a foo * parameter can be changed to const foo *. this change is always safe. sometimes an int parameter can be changed to unsigned int, or an int * parameter can be changed to unsigned int *. whether such a change is safe needs to be reviewed on a case-by-case basis. types structs members of an exported struct, cannot be reordered or removed. under certain circumstances, it i...

PKCS11 Implement
e attributes correctly. token initialization software that you supply should also set these fields. use of key ids the nss associates a key with its certificates by its key id (cka-id). it doesn't matter how the key id is generated, as long as it is unique for the token and maps to a certificate to it associated private key. more than one certificate can point to the same private key. the only exception to this requirement involves key generation for a new certificate, during which an orphan key waits for a brief time for a matching certificate. the nss uses part of the public key (modulus for rsa, value for dsa) as the key id during this time. nss doesn't require token public keys, but if they exist, nss expects the value of the cka_id attribute to be associated with private key and any related...

Multithreading in Necko
thread safe as most of mozilla (and especially most of gecko) run only on the main/primordial thread. in the future, necko may be made thread safe to support changes to gecko that would put some other processing work on background threads (eg. multithreaded image decoding). however, most necko protocols utilize background threads. background threads are used to manage all i/o operations (with the exception of few cases). most simple protocol handlers (eg. file, finger, datetime) do not worry about threading issues. the internal i/o interfaces default to proxying all callbacks to the main thread. this keeps simple protocol handlers simple :-) more complex protocol handlers (eg. http, ftp) operate partially on the background threads to improve performance. for example, the http protocol handler has c...

Rhino Debugger
the go button on the toolbar press the f5 key on the keyboard execution will resume until a breakpoint is hit or the script completes. break to stop all running scripts and give control to the debugger you may do any of the following: select the debug->break menu item on the menu bar press the break button on the toolbar press the pause/break key on the keyboard break on exceptions to give control to the debugger whenever a javascript is exception is thrown select the debug->break on exceptions checkbox from the menu bar. whenever a javascript exception is thrown by a script a message dialog will be displayed and control will be given to the debugger at the location the exception is raised. break on function enter selecting debug->break on function enter will give con...

Tutorial: Embedding Rhino
string, javascript object, or other values. the tostring method converts any javascript value to a string. exiting the context the code } finally { context.exit(); } exits the context. this removes the association between the context and the current thread and is an essential cleanup action. there should be a call to exit for every call to enter. to make sure that it is called even if an exception is thrown, it is put into the finally block corresponding to the try block starting after context.enter(). expose java apis using java apis no additional code in the embedding needed! the javascript feature calledliveconnect allows javascript programs to interact with java objects: $ java runscript "java.lang.system.out.println(3)" 3.0 undefined implementing interfaces using rhino, javascr...

Rhino FAQ
g.string, 5); then if you wish to assign the string "hi" to the first element, simply execute stringarray[0] = "hi". creating arrays of primitive types is slightly different: you must use the type field. for example, creating an array of seven ints can be done with the code var intarray = java.lang.reflect.array.newinstance(java.lang.integer.type, 7); when i try to execute a script i get the exception required security context missing. what's going on? you've likely missed placing the security.properties file in your class path at org.mozilla.javascript.resources. can i use rhino in a web browser? rhino is a library for java use, and not for general web browsers. however, a java-based browser may use rhino with scripts from a page in the same manner that any other java program would. ...

Creating JavaScript tests
one of the other appropriate subdirectories of jit-test/tests. jit-tests run only in the shell. jit-tests do not load extra test functionality automatically. writing a new test file have a look at the existing files and follow what they do. all tests, in both suite, can use the asserteq function. asserteq(v1, v2[, message]) check that v1 and v2 are the same value. if they're not, throw an exception (which will cause the test to fail). if you are writing a jstests, additional testing functionality is provided for you in shell.js files. you can read about them here. performance testing and general advice do not attempt to test the performance of engine features in the test suite. please keep in mind that the javascript test suite is run on a wide variety of wildly varying hardware plafor...

GC Rooting Guide
*> autoscriptvector if your case is not covered by one of these, it is possible to write your own by deriving from js::customautorooter and overriding the virtual trace() method. the implementation should trace all the gc things contained in the object by calling js::traceedge. gc things on the heap js::heap<t> gc thing pointers on the heap must be wrapped in a js::heap<t>. the only exception to this is if they are added as roots with the js::persistentrooted class, but don't do this unless it's really necessary. js::heap<t> pointers must also continue to be traced in the normal way, which is covered below. js::heap<t> doesn't require a jscontext*, and can be constructed with or without an initial value parameter. like the other template classes, it functions as if it were the gc t...

SpiderMonkey Internals: Thread Safety
in which js objects live. they can't travel to other jscompartments. crucially, any given compartment may only be accessed by one thread at a time. this means that objects cannot be shared across compartments. all js code and most jsapi calls run within a jscontext. the jscontext can be thought of as a machine that knows how to run javascript code, or as an abstraction of the notion of a thread. exception handling, for example, is per-jscontext. each jscontext must be used by only one thread at a time. a single jscontext can run work with code and objects in multiple compartments as long as no other thread is accessing those compartments. objects may be shared among jscontexts within a jscompartment. there's no fixed association between an object and a context. thread-safety in spidermonkey is tur...

Self-hosted builtins in SpiderMonkey
be installed as the host object's method foreach. making jsnatives available to self-hosted code for a jsnative to be available to self-hosted code, add it to the intrinsic_functions jsfunctionspec array in selfhosting.cpp. debugging self-hosted code self-hosted code by default is hidden from client javascript code; in particular, self-hosted frames will be filtered out of the stack traces of exceptions. to include self-hosted frames in stack traces (in debug builds only), set the environment variable moz_show_all_js_frames. ...

SpiderMonkey Internals
booleans, dates, functions, numbers, and strings are implemented using the js api. most are jsfastnatives. most string methods are customized to accept a primitive string as the this argument. (otherwise, spidermonkey converts primitive values to objects before invoking their methods, per ecma 262-3 §11.2.1.) error handling spidermonkey has two interdependent error-handling systems: javascript exceptions (which are not implemented with, or even compatible with, any kind of native c/c++ exception handling) and error reporting. in general, both functions inside spidermonkey and jsapi callback functions signal errors by calling js_reporterror or one of its variants, or js_setpendingexception, and returning js_false or null. public apis the public c/c++ interface, called the jsapi, is in most plac...

JS::CreateError
ame, uint32_t linenumber, uint32_t columnnumber, jserrorreport *report, handlestring message, mutablehandlevalue rval); name type description cx jscontext * pointer to a js context from which to derive runtime information. requires request. in a js_threadsafe build, the caller must be in a request on this jscontext. type jsexntype the exception's type. stack js::handlestring or js::handleobject the value of error.prototype.stack. filename js::handlestring the value of error.prototype.filename. linenumber uint32_t the value of error.prototype.linenumber. columnnumber uint32_t the value of error.prototype.columnnumber. report jserrorreport * a pointer to jserrorrep...

JS::OrdinaryToPrimitive
ev 28 (2014 oct 14) 7.1.1, second algorithm. most users should not call this -- use js::tonumber, js::toboolean, or js::tostring instead. this should only be called from custom convert hooks. it implements the default conversion behavior shared by most objects in js, so it's useful as a fallback. on success, js::ordinarytoprimitive stores the converted value in *vp and returns true. on error or exception, it returns false, and the value left in *vp is undefined. see also mxr id search for js::ordinarytoprimitive js::tonumber js::toboolean js::tostring bug 1103152 ...

JS::SetOutOfMemoryCallback
data parameter which will be passed to js::outofmemorycallback. added in spidermonkey 38 callback syntax typedef void (* outofmemorycallback)(jscontext *cx, void *data); name type description data void * data parameter passed to js::setoutofmemorycallback. added in spidermonkey 38 description unlike the error reporter, which is only called if the exception for an oom bubbles up and is not caught, the js::outofmemorycallback is called immediately at the oom site to allow the embedding to capture the current state of heap allocation before anything is freed. if the large-allocation-failure callback is called at all (not all allocation sites call the large-allocation-failure callback on failure), it is called before the out-of-memory callback; the out...

JS::ToInt32
v js::handlevalue the value to convert. out int32_t * out parameter. on success, *out receives the converted floating-point value. description js::toint32 converts a javascript value to a signed 32bit integer. it implements the toint32 operator described in ecma 262-3 §9.5. on success, js::toint32 stores the converted value in *out and returns true. on error or exception, it returns false, and the value left in *out is undefined. see also mxr id search for js::toint32 bug 739541 ...

JS::ToInt64
afe build, the caller must be in a request on this jscontext. v js::handlevalue the value to convert. out int64_t * out parameter. on success, *out receives the converted floating-point value. description js::toint64 converts a javascript value to a signed 64bit integer. on success, js::toint64 stores the converted value in *out and returns true. on error or exception, it returns false, and the value left in *out is undefined. see also mxr id search for js::toint64 bug 742188 ...

JS::ToNumber
ontext. v js::handlevalue the value to convert. out double * out parameter. on success, *out receives the converted floating-point value. description js::tonumber converts a javascript value to a number. it implements the tonumber operator described in ecma 262-3 §9.3. on success, js::tonumber stores the converted value in *out and returns true. on error or exception, it returns false, and the value left in *out is undefined. see also mxr id search for js::tonumber bug 739541 ...

JS::ToPrimitive
ing type as a hint, or jstype_void to pass no hint. do not pass any other type. vp js::mutablehandleobject out parameter. on success, *vp receives the converted value. description js::toprimitive converts a javascript object, obj, to a primitive value using ecmascript 6 toprimitive. on success, js::toprimitive stores the converted value in *vp and returns true. on error or exception, it returns false, and the value left in *vp is undefined. see also mxr id search for js::toprimitive js::getfirstargumentastypehint js_defaultvalue -- old name of this function bug 1054756 - added ...

JS::ToString
. requires request. in a js_threadsafe build, the caller must be in a request on this jscontext. v js::handlevalue the value to convert. description js::tostring returns a string representation of a javascript value. if v.isstring() is true, it calls v.tostring(). otherwise, it converts the value to string. on success, js::tostring returns a jsstring instance. on error or exception, it returns nullptr. see also mxr id search for js::tostring bug 933834 ...

JS::ToUint16
v js::handlevalue the value to convert. out uint16_t * out parameter. on success, *out receives the converted floating-point value. description js::toint16 converts a javascript value to an unsigned 16bit integer. it implements the toint16 operator described in ecma 262-3 §9.7. on success, js::toint16 stores the converted value in *out and returns true. on error or exception, it returns false, and the value left in *out is undefined. see also mxr id search for js::touint16 bug 779601 ...

JS::ToUint32
js::handlevalue the value to convert. out int32_t * out parameter. on success, *out receives the converted floating-point value. description js::touint32 converts a javascript value to an unsigned 32bit integer. it implements the touint32 operator described in ecma 262-3 §9.5. on success, js::touint32 stores the converted value in *out and returns true. on error or exception, it returns false, and the value left in *out is undefined. see also mxr id search for js::touint32 bug 739541 ...

JS::ToUint64
build, the caller must be in a request on this jscontext. v js::handlevalue the value to convert. out uint64_t * out parameter. on success, *out receives the converted floating-point value. description js::toint64 converts a javascript value to an unsigned 64bit integer. on success, js::toint64 stores the converted value in *out and returns true. on error or exception, it returns false, and the value left in *out is undefined. see also mxr id search for js::touint64 bug 742188 ...

JS::Value
presentations are visible using the separate int32/double methods but do not affect observable semantics (ignoring performance). the number mutators attempt to use int32_t representation for compatible input values, returning true when int32 could be used and false when double representation was required. any double value may be stored in a js::value, in one of these two representations. the only exception is that only a single nan value can be represented. (note that both -0 and +0 are allowed, and the latter may sometimes be stored using the int32_t representation.) js::value further provides these methods combining various aspects of the above methods: js::objectornullvalue(jsobject*) returns an object value corresponding to the given non-null pointer, or a null value if the pointer is null.

JSBool
is obsolete. although it may still work in some browsers, its use is discouraged since it could be removed at any time. try to avoid using it. every instance of jsbool has been replaced by bool. js_true has been replaced by just true and in the same way js_false by false. jsbool is the return type of many jsapi functions and callbacks. js_true indicates success; js_false indicates an error or exception occurred. jsbool is an integer type. js_true is (jsbool) 1 and js_false is (jsbool) 0. these values must not be used as jsvals. instead, use jsval_true and jsval_false, and use boolean_to_jsval and jsval_to_boolean to convert. ...

JSCheckAccessOp
he object whose properties are being accessed. id jsval the name or index of the property being accessed. mode jsaccessmode the type of access being checked. vp jsval * out parameter. on success, the callback must set *vp to the stored value of the property. description check whether obj[id] may be accessed per mode, returning js_false on error/exception, js_true on success with obj[id]'s stored value in *vp. as for jspropertyop, id is either a string or an int jsval. jscheckaccessop implementations generally work by using jsdbgapi functions such as js_frameiterator and js_stackframeprincipals to obtain the principals of the code attempting the checked operation, then examining those principals and comparing them with the system's security polic...

JSDeletePropertyOp
rtyop callback is a hook that applications may install to be called at some point during property access. a jsdeletepropertyop may be installed on a jsclass to hook property deletes. if a jsdeletepropertyop does nothing and returns true, then property delete is unaffected. it proceeds as normal. this callback may veto the ongoing property operation by optionally reporting an error or raising an exception and then returning false. the operation then fails, and the error is propagated to the caller. otherwise the callback must return true, and the property operation proceeds. jsclass hooks jsclass offers the following hook: jsclass.delproperty is called during most property deletions, even when obj has no property named id. if an error occurred, return false as per normal jsapi error pra...

JSExnType
value prototype in javascript jsexn_none an unthrowable error. (lower bound) jsexn_err error jsexn_internalerr internalerror jsexn_evalerr evalerror jsexn_rangeerr rangeerror jsexn_referenceerr referenceerror jsexn_syntaxerr syntaxerror jsexn_typeerr typeerror jsexn_urierr urierror jsexn_limit (upper bound) description these types are part of a jserrorformatstring structure. they define which error to throw in case of a runtime error. jsexn_none marks an unthrowable error. ...

JSExtendedClass.wrappedObject
a string that contains the name of the wrapped object's class rather than the wrapper's class. in typeof expressions and in js_typeofvalue, the type of the wrapped object is returned. (the result may be "object", "function", or "xml".) when assigning to __proto__ or __parent__ from script, the javascript engine checks to see if the assignment would produce a cycle. if so, it fails with an exception. when walking the chain to do this check, wrappers are automatically unwrapped. a wrapper object is strictly equal to the object it wraps, in the sense of === and !==. two wrapper objects that wrap the same object are also strictly equal. object.prototype.eval unwraps. a wrapper object that wraps an array is considered an array for the purpose of array.prototype.concat and array.conca...

JSFastNative
ly in the return-value slot. js_set_rval(cx, vp, value) sets the return value of the native function. it is safe to call this multiple times within a single call to a jsfastnative. if the jsfastnative returns js_true, the last value passed to this macro will be returned to the caller. on success, the callback must call js_set_rval (at least once) and return js_true. on error or exception, it must return js_false. to create a jsfunctionspec that points to a jsfastnative, use js_fn. when a jsfastnative is called, no jsstackframe is generated. this is what makes a fast native fast. however, it causes the function not to appear on the stack in javascript debuggers. it also means that applications that use spidermonkey's security features, particularly those that implement jschecka...

JSHasInstanceOp
ich the type check is occurring. obj js::handleobject the "type" in the type check. v js::mutablehandlevalue the value whose type is being checked. bp bool * out parameter. on success, the callback stores the result of the type check in *bp. description jshasinstanceop is called to check whether v is an instance of obj. return false on error or exception, true on success with true in *bp if v is an instance of obj, false in *bp otherwise. jsclass hooks jsclass offers the following hook: the jsclass.hasinstance callback implements js_hasinstance and the javascript instanceof keyword. see also mxr id search for jshasinstanceop jsclass js_hasinstance ...

JSID_VOID
an additional jsid which is used to indicate the absence of a valid jsid. syntax const jsid jsid_void; const js::handleid jsid_voidhandle; // added in spidermonkey 31 description jsid_void does not occur in js scripts but may be used to indicate the absence of a valid jsid. a void jsid is not a valid id and only arises as an exceptional api return value, such as in js_nextproperty. embeddings must not pass jsid_void into jsapi entry points expecting a jsid and do not need to handle jsid_void in hooks receiving a jsid except when explicitly noted in the api contract. jsid_voidhandle is the handle to the jsid which value is jsid_void. see also mxr id search for jsid_void mxr id search for jsid_voidhandle bug 912411 ...

JSIteratorOp
should take place. obj jsobject * pointer to the object to iterate over. keysonly jsbool if true, the iterator should yield keys only, not [key, value] pairs. description the javascript engine calls the jsextendedclass.iteratorobject callback to create an iterator object for a given object. the callback should return an iterator object or null if an error or exception occurred on cx. see also bug 909178 ...

JSObjectOp
obsolete since javascript 1.8.5this feature is obsolete. although it may still work in some browsers, its use is discouraged since it could be removed at any time. try to avoid using it. jsobjectop is the type of several jsapi callbacks that map an object to another object, or null if an error or exception occurred. typedef jsobject * (*jsobjectop)(jscontext *cx, jsobject *obj); the callbacks of this type are: jsextendedclass.outerobject jsextendedclass.innerobject jsextendedclass.wrappedobject jsobjectops.thisobject ...

JSObjectOps.defaultValue
behavior for ordinary objects is as described in es5 §8.12.8. it calls the javascript methods obj.valueof() and/or obj.tostring(). provide a custom jsobjectops.defaultvalue callback to implement customized [[defaultvalue]] behavior. the jsclass.convert callback should convert obj to the given type, returning js_true with the resulting value in *vp on success, and returning js_false on error or exception. on success, *vp must be a primitive value: per es5 §8.12.8, every object "must ensure that its [[defaultvalue]] internal method can return only primitive values." debug builds of spidermonkey will assert if a convert callback is successful but leaves *vp holding a primitive value. js_convertstub implements the default behavior for the jsclass.convert hook, which is to call obj.valueof() and ob...

JSObjectOps.getAttributes
re being accessed. id jsid the name or index of the property whose attributes are being accessed. prop jsproperty * the property whose attributes are being accessed. this may be null. attrsp unsigned int * in/out parameter. see the description section below. description get or set attributes of the property obj[id]. returns js_false on error or exception, else js_true with current attributes in *attrsp. if prop is non-null, it must come from the *propp out parameter of a prior jsobjectops.defineproperty or jsobjectops.lookupproperty call. for more information on property attributes, see js_getpropertyattributes. ...

JSObjectOps.getProperty
e description cx jscontext * pointer to the js context in which the property access is happening. obj jsobject * the object to be accessed. id jsid the name or index of the property to access. vp jsval * in/out parameter. see the description section below. description get, set, or delete obj[id], returning js_false on error or exception, js_true on success. if getting or setting, the new value is returned in *vp on success. if deleting without error, *vp will be jsval_false if obj[id] is permanent, and jsval_true if id named a direct property of obj that was in fact deleted, or if id names no direct property of obj (id could name a property of a prototype, or no property in obj or its prototype chain). this reflects the quirky ...

JSObjectOps.lookupProperty
p. objp jsobject ** out parameter. if the property is found, the callback stores the object on which the property was found in *objp. propp jsproperty ** out parameter. on success, the callback stores in *propp a pointer to the property, if it exists, or null if it doesn't. description look for id in obj and its prototype chain, returning js_false on error or exception, js_true on success. on success, return null in *propp if id was not found. if id was found, return the first object searching from obj along its prototype chain in which id names a direct property in *objp, and return a non-null, opaque property pointer in *propp. if jslookuppropop succeeds and returns with *propp non-null, that pointer may be passed as the prop parameter to a jsattributesop, a...

JSObjectPrincipalsFinder
cipals finder callback is a key security feature. the callback returns a pointer to the principals associated with obj, possibly via the immutable parent chain leading from obj to a top-level container (such as a window object in the dom). if there are no principals associated with obj, return null. therefore null does not mean an error was reported; in no event should an error be reported or an exception be thrown by this callback's implementation. the callback should not call jsprincipals_hold. see also bug 784551 ...

JSPropertyOp
r it may be installed on a jsclass to hook property gets, sets, or adds. these different cases are described in more detail in the sections below. if a jspropertyop or jsstrictpropertyop does nothing and returns true, then property get, set, or add is unaffected. it proceeds as normal. each of these callbacks may veto the ongoing property operation by optionally reporting an error or raising an exception and then returning false. the operation then fails, and the error is propagated to the caller. otherwise the callback must return true, and the property operation proceeds. getters and setters when a jsapi application creates a property on an object (for example, using js_defineproperty or js_defineproperties) it can specify getter and setter callbacks for the new property. getters. the getter...

JSRuntime
stance of the javascript engine. a program typically has only one jsruntime, even if it has many threads. the jsruntime is the universe in which javascript objects live; they can't travel to other jsruntimes. all javascript code and most jsapi calls run within a jscontext. the jscontext is a child of the jsruntime. a context can run scripts. it contains the global object and the execution stack. exception handling, error reporting, and some language options are per-jscontext. once created, a context can be used any number of times for different scripts or jsapi queries. for example, a browser might create a separate context for each html page; every script in the page could use the same context. objects may be shared among jscontexts within a jsruntime. there's no fixed association between an obj...

JSTraceOp
unction type for trace operation of the class called to enumerate all traceable things reachable from obj's private data structure. for each such thing, a trace implementation must call one of the js_call*tracer variants on the thing. jstraceop implementation can assume that no other threads mutates object state. it must not change state of the object or corresponding native structures. the only exception for this rule is the case when the embedding needs a tight integration with gc. in that case the embedding can check if the traversal is a part of the marking phase through calling js_isgcmarkingtracer and apply a special code like emptying caches or marking its native structures. jsclass hooks jsclass offers the following hook: the jsclass.trace callback is called to enumerate all tracea...

JS_AlreadyHasOwnProperty
dp is set to true only if lookupproperty reports that the property was found on obj itself and not on some other object (even the corresponding outer object, if any). if the property is found on obj, this sets *foundp to true and returns true. if the property is not found on obj, this sets *foundp to false and returns true (to indicate that no error occurred). if the search fails with an error or exception, this returns false. see also mxr id search for js_alreadyhasownproperty mxr id search for js_alreadyhasownucproperty mxr id search for js_alreadyhasownpropertybyid mxr id search for js_alreadyhasownelement bug 400793 bug 461163 ...

JS_CheckAccess
, then it is called to perform the check. otherwise, if a runtime-wide check-object-access callback has been installed by calling js_setcheckobjectaccesscallback, then that is called to perform the check. otherwise, access is granted. on success, js_checkaccess returns js_true, *vp is set to the current value of the specified property, and *attrsp is set to the property's attributes. on error or exception, including if access is denied, js_checkaccess returns js_false, and the values left in *vp and *attrsp are undefined. mxr id search for js_checkaccess ...

JS_CompileFunction
mpilation. similarly, lineno is used to report the line number where an error occurred during compilation. if both obj and name are non-null, the new function becomes a method of obj. (a new property is defined on obj with the given name and the new function object as its value.) on success, js_compilefunction and js_compileucfunction return a pointer to the newly compiled function. on error or exception, they return null. see also mxr id search for js_compilefunction mxr id search for js_compileucfunction jsfun_bound_method jsfun_global_parent js_callfunction js_callfunctionname js_callfunctionvalue js_decompilefunction js_decompilefunctionbody js_definefunction js_definefunctions js_getfunctionobject js_newfunction js_setbranchcallback js_valuetofunction bug 1089026 ...

JS_CompileFunctionForPrincipals
is the name of the file (or url) containing the function. this information is passed in messages if an error occurs during compilation. similarly, lineno is used to report the line number of the function or file where an error occurred during compilation. on success, js_compilefunctionforprincipals and js_compileucfunctionforprincipals return a pointer to the newly compiled function. on error or exception, they return null. see also mxr id search for js_compilefunctionforprincipals mxr id search for js_compileucfunctionforprincipals jsfun_bound_method jsfun_global_parent js_callfunction js_callfunctionname js_callfunctionvalue js_compilefunction js_decompilefunction js_decompilefunctionbody js_definefunction js_definefunctions js_getfunctionobject js_newfunction js_valuetofunctio...

JS_CompileScriptForPrincipals
ilename is the name of the file (or url) containing the script. this information is included in error messages if an error occurs during compilation. similarly, lineno is used to report the line number of the script or file where an error occurred during compilation. on success, js_compilescriptforprincipals and js_compileucscriptforprincipals return a pointer to the compiled script. on error or exception, they return null. the application is responsible for ensuring that the new compiled script is cleaned up later—either by calling js_destroyscript() directly or by calling js_newscriptobject(), in which case the garbage collector cleans up the script. warning: this api is subject to bug 438633, which can cause crashes in almost any program that uses js_destroyscript(). the workaround is to u...

JS_ConvertValue
tion object that has not been stripped of its lexical scope. it is safe to call the result (e.g. using js_callfunctionvalue). converting to jstype_string works like js::tostring. converting to jstype_number works exactly like js::tonumber. converting to jstype_boolean works exactly like js::toboolean. on success, js_convertvalue stores the converted value in *vp and returns true. on error or exception, it returns false, and the value left in *vp is undefined. see also mxr id search for js_convertvalue js_convertarguments js_gettypename js_typeofvalue bug 1125784 ...

JS_DefaultValue
cts). objects with a custom jsclass specified by the embedder will invoke that class's convert hook, which must convert the object to a primitive value, to determine the primitive result of conversion. behavior when the convert hook is js_convertstub is identical to that for objects defined by ecmascript. on success, js_defaultvalue stores the converted value in *vp and returns true. on error or exception, it returns false, and the value left in *vp is undefined. see also mxr id search for js_defaultvalue js::toprimitive bug 1054756 - renamed to js::toprimitive ...

JS_DefineFunction
be exposed to javascript. nargs indicates the number of arguments the function expects to receive. this becomes the new function object's length property and can be accessed using js_getfunctionarity. flags is the logical or of zero or more property attributes, which apply to the new property. on success, js_definefunction and js_defineucfunction return a pointer to the new function. on error or exception, they return null. see also mxr id search for js_definefunction mxr id search for js_defineucfunction mxr id search for js_definefunctionbyid js_callfunctionname js_callfunctionvalue js_compilefunction js_definefunctions js_defineobject js_defineproperties js_defineproperty js_getfunctionobject js_newfunction bug 607695 - added js_definefunctionbyid ...

JS_DefineFunctions
ain 0 values. (the macro js_fs_end can be used for the last element.) js_definefunctions creates one function for each non-zero element in the array. propertydefinitionbehavior is used to select if properties with jsprop_define_late flag should be defined on the object. normal jsapi consumers probably always want defineallproperties here. on success, js_definefunctions returns true. on error or exception, it stops defining functions and returns false. see also mxr id search for js_definefunctions js_callfunctionname js_defineobject js_defineproperties js_newfunction bug 959787 - make fs type to const bug 825199 - added propertydefinitionbehavior ...

JS_DefineObject
operty of an existing object, obj. name is the property name to assign to obj to hold the new object, and flags contains the property attributes to set for the newly created property. the new object's parent is obj. js_defineobject does not call clasp->constructor. initialization of the new object is up to the caller. on success, js_defineobject returns a pointer to the new object. on error or exception (if the object cannot be created, the property already exists, or the property cannot be created), js_defineobject returns null. this function combines two operations: creating an object and storing it in a property of another object. use js_constructobject, js_constructobjectwitharguments, or js_newobject to create a new object without storing it in a property of another object. use js_definepr...

JS_DeleteProperty
r. otherwise obj has a non-permanent own property with the given name or id. in this case, obj's jsclass.delproperty hook is called. if the hook returns false, the error is propagated. otherwise, if obj is not configurable, an error is raised. otherwise, the property is removed. these functions return true on success, regardless of whether a property was actually deleted, and false on error or exception. (in javascript 1.2 and earlier, attempting to delete a permanent property caused an error. there is no longer any way to get this behavior.) internally, property deletion is implemented by the jsobjectops.deleteproperty callback. to remove all properties from an object, call js_clearscope. see also mxr id search for js_deleteproperty mxr id search for js_deletepropertybyid js_deleteprop...

JS_DeleteProperty2
n this case, *succeeded is set to true and obj's jsclass.delproperty hook is called (which may change *succeeded). if the hook returns false, the error is propagated. otherwise, if obj is not configurable, an error is raised. otherwise, *succeeded receives true and the property is removed. these functions return true on success, regardless of whether a property was actually deleted. on error or exception, the return value is false, and the value left in *succeeded is unspecified. jsobjectops.deleteproperty implements this behavior. (in javascript 1.2 and earlier, attempting to delete a permanent property caused an error. there is no longer any way to get this behavior.) to remove all properties from an object, call js_clearscope. see also mxr id search for js_deleteproperty2 mxr id search...

JS_Enumerate
inherited from the object's prototype.) this is not quite the same behavior as a javascript for...in loop, which converts all property ids to strings and also enumerates inherited properties. this calls obj's jsclass.enumerate hook. on success, js_enumerate returns a pointer to the first element of an array of property ids. the application must free this array using js_destroyidarray. on error or exception, js_enumerate returns null. the property ids in the returned jsidarray are subject to garbage collection. as long as obj is reachable, its current property ids are reachable. but, for example, if an application calls back into javascript while it is looping over the property ids in the jsidarray, the script could delete properties from obj. the property ids would then become unreachable and c...

JS_ForwardGetPropertyTo
s_forwardgetpropertyto is the base implementation of js_getproperty, js_getucproperty, js_getpropertybyid etc, where onbehalfof is same to obj. onbehalfof is receiver in [[get]] internal method of proxy, defined in es2015 draft spec (rev 29, 9.5.8). on success, these functions set *vp to the current value of the property, or undefined if obj has no such property, and return true. on an error or exception, these functions return false, and the value left in *vp is undefined. see also mxr id search for js_forwardgetpropertyto js_getproperty bug 698551 ...

JS_GetElement
e of the element, if it exists, and undefined otherwise. description js_getelement examines a specified js object, obj, and its prototype chain, for an element or numeric property numbered index. if the element exists, js_getelement sets *vp to the element's current value. if not, it sets *vp to undefined and returns true (to indicate no error occurred). if the search fails with an error or exception, js_getelement returns false, and the value left in *vp is undefined. see also mxr id search for js_getelement js_defineelement js_deleteelement js_getarraylength js_isarrayobject js_lookupelement js_newarrayobject js_setarraylength js_setelement ...

JS_GetProperty
getter does nothing and returns true, so the property get succeeds and the property's stored value is left in *vp. internally, property retrieval, including all the behavior described above, is implemented by obj's jsobjectops.getproperty callback. on success, these functions set *vp to the current value of the property, or undefined if obj has no such property, and return true. on an error or exception, these functions return false, and the value left in *vp is undefined. see also mxr id search for js_getproperty mxr id search for js_getucproperty mxr id search for js_getpropertybyid example in the jsapi phrasebook js_defineproperty js_definepropertywithtinyid js_deleteproperty js_deleteproperty2 js_lookupproperty js_propertystub js_setproperty bug 461163 ...