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.
... (function () { debug.setnonusercodeexceptions = true; try{ var x = null; x.y(); } catch (e) { // catch the exception.

Components.Exception
summary 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.
... see also nsixpcexception.
... syntax var exception = [ new ] components.exception([ message [, result [, stack [, data ] ] ] ]); parameters message a string which can be displayed in the error console when your exception is thrown or in other developer-facing locations, defaulting to 'exception' result the nsresult value of the exception, which defaults to components.results.ns_error_failure stack an xpcom stack to be set on the exception (defaulting to the current stack chain) data any additional data you might want to store, defaulting to null example throw components.exception("i am throwing an exception from a javascript xpcom component."); ...

IDBDatabaseException - Web APIs
obsolete: this interface was removed from the specification and was replaced by usage of domexception.
... in the indexeddb api, an idbdatabaseexception object represents exception conditions that can be encountered while performing database operations.
... message domstring error message describing the exception raised.
... desktopmobilechromeedgefirefoxinternet exploreroperasafariandroid webviewchrome for androidfirefox for androidopera for androidsafari on iossamsung internetidbdatabaseexception deprecatednon-standardchrome full support 12prefixed full support 12prefixed prefixed implemented with the vendor prefix: webkitedge full support ≤79prefixed full support ≤79prefixed prefixed implemented with the ...

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.
... learn more general knowledge exception handling on wikipedia ...

JSExceptionState
this is used to save and restore exception states.
... syntax struct jsexceptionstate; description a jsexceptionstate object is returned by the js_saveexceptionstate function, and is passed to functions js_restoreexceptionstate and js_dropexceptionstate.
... see also mxr id search for jsexceptionstate js_saveexceptionstate js_restoreexceptionstate js_dropexceptionstate ...

nsIException
xpcom/base/nsiexception.idlscriptable please add a summary to this article.
... inner nsiexception an inner exception that triggered this, if available.
... result nsresult the nsresult associated with this exception.

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.
... stylenode nsidomnode the node in the stylesheet that triggered the exception.

DOMException.code - Web APIs
the code read-only property of the domexception interface returns a short that contains one of the error code constants, or 0 if none match.
...new dom exceptions don't use this anymore: they put this info in the domexception.name attribute.
... syntax var domexceptioncode = domexceptioninstance.code; value a short number.

FileException - Web APIs
in the file system api, a fileexception object represents error conditions that you might encounter while accessing the file system using the synchronous api.
... it extends the fileexception interface described in file writer and adds several new error codes.
... desktopmobilechromeedgefirefoxinternet exploreroperasafariandroid webviewchrome for androidfirefox for androidopera for androidsafari on iossamsung internetfileexception deprecatednon-standardchrome no support 13 — 29prefixed no support 13 — 29prefixed prefixed implemented with the vendor prefix: webkitedge no support nofirefox no support noie no support noopera ...

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.

XPathException - Web APIs
in the dom xpath api the xpathexception interface represents exception conditions that can be encountered while performing xpath operations.
... properties xpathexception.code read only returns a short that contains one of the error code constants.
... specifications specification status comment document object model (dom) level 3 xpath specificationthe definition of 'xpathexception' in that specification.

nsIDOMFileException
the nsidomfileexception interface represents exceptions that can be raised by calls to the methods in the nsidomfile interface.
... content/base/public/nsidomfileexception.idlscriptable please add a summary to this article.

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.

DOMException.message - Web APIs
the message read-only property of the domexception interface returns a domstring representing a message or description associated with the given error name.
... syntax var domexceptionmessage = domexceptioninstance.message; value a domstring.

DOMException.name - Web APIs
the name read-only property of the domexception interface returns a domstring that contains one of the strings associated with an error name.
... syntax var domexceptionname = domexceptioninstance.name; value a domstring.

NPN_SetException - Archive of obsolete content
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.

nsIDOMXPathException
dom/interfaces/xpath/nsidomxpathexception.idlscriptable describes an exception resulting from xpath operations.

nsIXPConnect
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!
... 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.
... atracer missing description exceptions thrown missing exception missing description clearallwrappednativesecuritypolicies() void clearallwrappednativesecuritypolicies(); parameters none.
...And 37 more matches

imgIContainer
exceptions thrown ns_error_not_available if the animated state cannot be determined.
...in the case of any error, zero is returned, and an exception will be thrown.
...in the case of any error, zero is returned, and an exception will be thrown.
...And 34 more matches

WebIDL bindings
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.
...And 32 more matches

LiveConnect Overview - Archive of obsolete content
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.
...And 27 more matches

Index - Web APIs
the number of channels in the input must be between 0 and the maxchannelcount value or an exception is raised.
...this occurs when the underlying audioworkletprocessor behind the node throws an exception in its constructor, the process method, or any user-defined class method.
...if this css value doesn't contain a counter value, a domexception is raised.
...And 27 more matches

Index
24 js::autosaveexceptionstate jsapi reference, reference, référence(2), spidermonkey js::autosaveexceptionstate saves and later restores the current exception state of a given jscontext.
...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.
... 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.
...And 24 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.
... 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.
...And 22 more matches

JSAPI User Guide
this causes a javascript exception to be thrown.
... the caller can catch the exception using a javascript try/catch statement.
... errors and exceptions the importance of checking the return value of jsapi functions, of course, goes without saying.
...And 21 more matches

Control flow and error handling - JavaScript
nanas are $0.48 a pound.'); break; case '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.
...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.
...And 20 more matches

nsIMsgIncomingServer
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()).
...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.
...And 16 more matches

nsIHttpChannel
exceptions thrown ns_error_failure if set after the channel has been opened.
...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.
...And 15 more matches

IDBObjectStoreSync - Web APIs
method overview 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 (idbdatabase...
...exception); 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 indexnames readonly domstringlist a list of the names of the indexes on this object store.
...if a record already exists with the given key, an exception is raised.
...And 13 more matches

nsIFile
exceptions thrown ns_error_file_not_directory indicates that this nsifile does not reference a directory.
... exceptions thrown ns_error_file_invalid_path indicates that this nsifile does not reference a symbolic link.
... exceptions thrown ns_error_file_unrecognized_path indicates that anode incorrectly contains a path separator character.
...And 12 more matches

IDBIndexSync - Web APIs
method overview any add (in any value, in optional any key) raises (idbdatabaseexception); any get (in any key) raises (idbdatabaseexception); any getobject (in any key) raises (idbdatabaseexception); void opencursor (in optional idbkeyrange range, in optional unsigned short direction) raises (idbdatabaseexception); void openobjectcursor (in optional idbkeyrange range, in optional unsigned short direction) raises (idbdatabaseexception); an...
...y put (in any value, in optional any key) raises (idbdatabaseexception); void remove (in any key) raises (idbdatabaseexception); attributes attribute type description keypath readonly domstring the key path of this index.
...if a record already exists with the given key, an exception is raised.
...And 12 more matches

Debugger - Firefox Developer Tools
changing this flag when any frame of the debuggee is currently active on the stack will produce an exception.
... 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.
... exceptions thrown in the debugger are not propagated to debuggee code; instead, spidermonkey calls this function, passingdebugger-exception as its sole argument and the debugger instance as the this value.
...And 11 more matches

throw - JavaScript
the throw statement throws a user-defined exception.
... description use the throw statement to throw an exception.
... when you throw an exception, expression specifies the value of the exception.
...And 11 more matches

Bytecode Descriptions
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.
...notable exceptions are arrow functions and derived or default class constructors.
...if resumekind is throw or return, these completions are handled by throwing an exception.
...And 10 more matches

nsIMsgHeaderParser
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.
... exceptions thrown missing exception missing description native code only!extractheaderaddressname like extractheaderaddressnames(), but only returns the first name in the list, if there is more than one.
... return value the first name found in the list exceptions thrown missing exception missing description makefulladdress() given an e-mail address and a person's name, concatenates them together into a single string, doing all the necessary quoting.
...And 10 more matches

Index
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.
...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.
...And 9 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...
...issing 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 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 miss...
...ing description getcharactersetoverride() obsolete since gecko 1.8 (firefox 1.5 / thunderbird 1.5 / seamonkey 1.0) void getcharactersetoverride( out boolean charactersetoverride ); parameters charactersetoverride missing description exceptions thrown missing exception missing description getcharptrcharacterset() string getcharptrcharacterset(); parameters none.
...And 9 more matches

nsIEffectiveTLDService
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.
...And 9 more matches

JSAPI Cookbook
*/ 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.
...note that javascript exceptions are not the same thing as c++ exceptions.
...use js_setpendingexception to throw an arbitrary js::value from c/c++.
...And 8 more matches

nsICrashReporter
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!
... exceptions thrown ns_error_not_initialized if crash reporting is not initialized.
...And 8 more matches

SVGTransformList - Web APIs
an svgtransformlist object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown.
... 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.
... 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.
...And 8 more matches

Promise
this may be any value, including undefined, though it is generally an error object, like in exception handling.
...if the executor throws an exception, its value will be passed to the reject resolving function.
...although the reason can be undefined, it is generally an error object, like in exception handling.
...And 7 more matches

Task.jsm
task.spawn() returns a promise that is resolved when the task completes successfully, or is rejected if an exception occurs.
...if the promise is rejected, its rejection reason is thrown as an exception.
... 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.
...And 7 more matches

nsIOutputStream
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.
... exceptions thrown ns_base_stream_would_block indicates that flushing the output stream would block the calling thread for an indeterminate amount of time.
...And 7 more matches

nsIZipWriter
attempting to perform a synchronous operation on the interface while the background queue is in progress will throw an ns_error_in_progress exception.
... exceptions thrown ns_error_not_initialized if no zip file has been opened.
... exceptions thrown ns_error_not_initialized no zip file is open.
...And 7 more matches

IDBDatabaseSync - Web APIs
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 (idbdatabas...
...eexception); attributes attribute type description description readonly domstring the human-readable description of the connected database.
... idbobjectstoresync createobjectstore( in domstring name, in domstring keypath, in optional boolean autoincrement ) raises (idbdatabaseexception); parameters name the name of a new object store.
...And 7 more matches

SVGLengthList - Web APIs
an svglengthlist object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown.
... 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.
... 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.
...And 7 more matches

SVGNumberList - Web APIs
an svgnumberlist object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown.
... 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.
... 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.
...And 7 more matches

SVGPointList - Web APIs
an svgpointlist object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown.
... 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.
... 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.
...And 7 more matches

SVGStringList - Web APIs
an svgstringlist object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown.
... 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.
... 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.
...And 7 more matches

FileSystemEntrySync - Web APIs
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 typ...
...[ 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.
... filesystementrysync moveto ( in directoryentrysync parent, optional domstring newname ) raises (fileexception); parameters parent the directory to which to move the entry.
...And 6 more matches

SVGPathSegList - Web APIs
exceptions: a domexception with code no_modification_allowed_err is raised when the list cannot be modified.
... exceptions: a domexception with code no_modification_allowed_err is raised when the list cannot be modified.
... exceptions: a domexception with code no_modification_allowed_err is raised when the list cannot be modified.
...And 6 more matches

Python binding for NSS
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.
...And 5 more matches

Shell global objects
on (default: false) filename filename for error messages and debug info linenumber starting line number for error messages and debug info columnnumber starting column number for error messages and debug info global global in which to execute the code newcontext if true, create and use a new cx (default: false) catchtermination if true, catch termination (failure without an exception value, as for slow scripts or out-of-memory) and return 'terminated' element if present with value v, convert v to an object o and mark the source as being attached to the dom element o.
...if an error occurred, throw the appropriate exception; otherwise, run the script and return its value.
...if an error occurred, throw the appropriate exception; otherwise, return the module object timeout([seconds], [func]) get/set the limit in seconds for the execution time for the current context.
...And 5 more matches

nsIRadioInterfaceLayer
connecting 9 call_state_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 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.
...And 5 more matches

nsITextInputProcessor
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.
...if this is specified with non-zero location attribute value, this causes throwing an exception since it doesn't make sense.
...And 5 more matches

Debugger.Frame - Firefox Developer Tools
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.
... 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.
...in frames returning or throwing an exception, the location is often a return or a throw statement.
...And 5 more matches

Debugger.Object - Firefox Developer Tools
if the referent is not a promise, throw a typeerror exception.
...if the referent is not a promise, throw a typeerror exception.
...if the referent is not a promise, throw a typeerror exception.
...And 5 more matches

CSSPrimitiveValue - Web APIs
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).
...if this css value doesn't contain a counter value, a domexception is raised.
...if this css value doesn't contain a float value or can't be converted into the specified unit, a domexception is raised.
...And 5 more matches

DirectoryEntrySync - Web APIs
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 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.
...And 5 more matches

Operable - Accessibility
to achieve aaa conformance, all functionality should be accessible using keyboard controls — with no exceptions.
... exceptions to this are activities with time limits longer than 20 hours, real time events (e.g.
...exceptions are where the link purpose is ambiguous to all users (see ambiguous to users in general for a useful explanation of this).
...And 5 more matches

Preferences - Archive of obsolete content
if there's a value of the wrong type and the preference is not locked, an ns_error_unexpected exception is thrown.
... 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 exception is thrown.
...And 4 more matches

Index - Archive of obsolete content
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 component, which threw an exception, that exception would be logged to the console before control was returned to the c++ caller.
...this content will be copied for each matching result (though see below for an exception) and inserted into the document.
...And 4 more matches

nsIAccessibleEditableText
exceptions thrown ns_error_failure indicates the text cannot be copied into the clipboard.
... exceptions thrown ns_error_failure indicates the text cannot be deleted or copied into the clipboard.
... exceptions thrown ns_error_failure indicates the text cannot be deleted.
...And 4 more matches

nsIContentPrefService
exceptions thrown ns_error_illegal_value if agroup is not a string, nsiuri, or null.
...exceptions thrown ns_error_illegal_value if agroup is not a string, nsiuri, or null.
...exceptions thrown ns_error_illegal_value if aname is null or an empty string.
...And 4 more matches

nsIControllers
exceptions thrown ns_error_out_of_memory getcontrollerat() returns the controller instance at the given position.
...exceptions thrown ns_error_failure the given index is out of range.
...exceptions thrown ns_error_failure the id is greater than the number of controllers that have been inserted, or the controller has since been removed.
...And 4 more matches

nsIFaviconService
throws an exception if we don't have data.
... exceptions thrown ns_error_not_available thrown when we have never heard of this favicon url.
... this method retrieves the given favicon data, returning it as a data url throws an exception if we don't have data.
...And 4 more matches

nsIScriptableIO
exceptions thrown ns_error_invalid_arg alocation was null.
...exceptions thrown ns_error_invalid_arg afilepath was null.
...exceptions thrown ns_error_invalid_arg auri was null.
...And 4 more matches

SVGAngle - Web APIs
an svgangle object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown.
... 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.
... 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.
...And 4 more matches

SVGLength - Web APIs
an svglength object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown.
... 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.
... 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.
...And 4 more matches

SVGTransform - Web APIs
an svgtransform object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown.
... exceptions: a domexception with code no_modification_allowed_err is raised when attempting to modify a read only attribute or when the object itself is read only.
... exceptions: a domexception with code no_modification_allowed_err is raised when attempting to modify a read only attribute or when the object itself is read only.
...And 4 more matches

Feature-Policy - HTTP
when this policy is disabled and there were no user gestures, the promise returned by htmlmediaelement.play() will reject with a domexception.
...when this policy is disabled, the promise returned by navigator.getbattery() will reject with a notallowederror domexception.
...when this policy is disabled, the promise returned by getusermedia() will reject with a notallowederror domexception.
...And 4 more matches

test/assert - Archive of obsolete content
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.
... to check that the exception thrown contains a specific message, pass a regular expression here: the message property of the exception thrown must match the regular expression for example, suppose we define two different custom exceptions: function myerror(message) { this.name = "myerror"; this.message = message || "default message"; } myerror.prototype = new error(); myerror.prototype.constructor = myerror; function anothererror(message) { this.name = "anothererror"; this.message = message || "default message"; console.log(this.message); } anothererror.prototype = new error(); anothererror.prototype.constructor = anothererror; we can check the type of exception by passing a function as the error argument: exports["test exception type 1 expected to pass"] = function(asse...
...And 3 more matches

Storage access policy: Block cookies from trackers
dom storage: localstorage: window.localstorage: read and write attempts throw a securityerror exception.
...thus, attempts to read and write using this object will throw a typeerror exception.
... indexeddb: attempting to access the indexeddb factory object throws a securityerror exception.
...And 3 more matches

Web Replay
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.
... 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.
...And 3 more matches

An Overview of XPCOM
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.
...And 3 more matches

nsIAccessNode
, in domstring propertyname); domstring getcomputedstylevalue(in domstring pseudoelt, in domstring propertyname); void scrollto(in unsigned long ascrolltype); void scrolltopoint(in unsigned long acoordinatetype, in long ax, in long ay); attributes note: attempting to access the attributes of a node that is unattached from the accessible tree will result in an exception - ns_error_failure.
... exceptions thrown ns_error_failure indicates that the access node is unattached from the accessible tree.
... exceptions thrown ns_error_failure indicates that the access node is unattached from the accessible tree.
...And 3 more matches

nsIDownloadManager
exceptions thrown ns_error_failure the download is not in progress.
... exceptions thrown ns_error_not_available the download is not in the database.
... exceptions thrown ns_error_failure the download is not in progress.
...And 3 more matches

nsIInputStream
a stream that is closed will throw an exception when this method is called.
... exceptions thrown <other-error> if the stream is closed due to some error condition.
... exceptions thrown <other-error> on failure.
...And 3 more matches

nsIURI
exceptions thrown ns_error_failure if host is not applicable to the uri scheme (e.g.
... exceptions thrown ns_error_failure if hostport is not applicable to the uri scheme (e.g.
... exceptions thrown ns_error_failure if password is not applicable to the uri scheme (e.g.
...And 3 more matches

HTMLTableElement - Web APIs
when set, if the object doesn't represent a <caption>, a domexception with the hierarchyrequesterror name is thrown.
...when set, if the object doesn't represent a <thead>, a domexception with the hierarchyrequesterror name is thrown.
...when set, if the object doesn't represent a <tfoot>, a domexception with the hierarchyrequesterror name is thrown.
...And 3 more matches

RTCPeerConnection.setRemoteDescription() - Web APIs
exceptions the following exceptions are reported to the rejection handler for the promise returned by setremotedescription(): invalidaccesserror the content of the description is invalid.
...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.
...this happens instead of throwing an exception, thereby reducing the number of potential errors which might occur, and simplifies the processing you need to do when you receive an offer, by eliminating the need to handle the offer/answer process differently depending on whether the local peer is the caller or callee.
...And 3 more matches

/loader - Archive of obsolete content
any attempt to load a module not listed in the manifest is unauthorized and is rejected with an exception: let { loader } = require('toolkit/loader'); let manifest = { './main': { 'requirements': { 'panel': 'sdk/panel' } }, 'sdk/panel': { 'requirements': { 'chrome': 'chrome' } } 'chrome': { 'requirements': {} } }; let loader = loader({ resolve: function(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.
...And 2 more matches

console/traceback - Archive of obsolete content
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.
...And 2 more matches

console - Archive of obsolete content
console methods all console methods except exception() and trace() accept one or more javascript objects as arguments and log them to the console.
... console.error(object[, object, ...]) logs the arguments to the console, preceded by "error:" and the name of your add-on: console.error("this is an error message"); error: my-addon: this is an error message console.exception(exception) logs the given exception instance as an error, outputting information about the exception's stack traceback if one is available.
... try { dothing(); } catch (e) { console.exception(e); } function userexception(message) { this.message = message; this.name = "userexception"; } function dothing() { throw new userexception("thing could not be done!"); } error: my-addon: an exception occurred.
...And 2 more matches

Venkman Introduction - Archive of obsolete content
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.
...you can also use commands available in the debug menu and from the console to stop at errors or at exceptions.
...if a property shows up in a bold red font, an exception occurred when venkman tried to read the value.
...And 2 more matches

Creating JavaScript jstest reftests
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.
...in the javascript shell, an uncaught exception or out of memory error will terminate the shell with an exit code of 3.
...And 2 more matches

mozIStorageConnection
exceptions thrown ns_error_unexpected thrown if the method was called on a thread other than the one that opened the connection.
... note: the database engine does not support nested transactions, so attempting to start a transaction when one is already active will throw an exception.
... exceptions thrown ns_error_unexpected the connection is to a memory database.
...And 2 more matches

nsIAccessibleHyperLink
note: renamed from anchors in gecko 1.9 exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree.
... exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree.
... exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree.
...And 2 more matches

nsIArray
exceptions thrown ns_error_failure if the array is empty (to make it easy to detect errors).
...note that since null is a valid input, exceptions are used to indicate that an element is not found.
...exceptions thrown ns_error_failure if the element was not in the array.
...And 2 more matches

nsICryptoHash
exceptions thrown ns_error_not_initialized indicates that init() or initwithstring() has not been called.
... exceptions thrown ns_error_invalid_arg indicates that an unsupported algorithm type was passed initwithstring() initialize the hashing object.
... 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.
...And 2 more matches

nsIIOService
exceptions thrown ns_error_malformed_uri if url string is not of the right form.
...the only exception to this is for loads from webworkers since they don't have any nodes to be passed as aloadingnode.
...the only exception to this is for loads from webworkers since they don't have any nodes to be passed as aloadingnode.
...And 2 more matches

nsILivemarkService
exceptions thrown ns_error_invalid_arg if the folder id isn't known or identifies a folder that isn't a livemark container.
... exceptions thrown ns_error_invalid_arg if the folder id isn't known or identifies a folder that isn't a livemark container.
... exceptions thrown ns_error_invalid_arg if the folder id isn't known.
...And 2 more matches

nsINavHistoryContainerResultNode
vhistoryresultnode findnodebydetails(in autf8string auristring, in prtime atime, in long long aitemid, in boolean arecursive); nsinavhistoryresultnode getchild(in unsigned long aindex); unsigned long getchildindex(in nsinavhistoryresultnode anode); attributes attribute type description childcount unsigned long the number of child nodes; accessing this throws an ns_error_not_available exception of containeropen is false.
...accessing this throws an exception if the node isn't a dynamic container.
...exceptions thrown ns_error_not_available the container is not open.
...And 2 more matches

Component; nsIPrefBranch
remarks note: prior to gecko 6.0, this method would throw an exception if there was no user value set for the specified preference.
... adefaultvalue requires gecko 54 optional - a default value to use if the preference does not exist (instead of throwing an exception).
... adefaultvalue requires gecko 54 optional - a default value to use if the preference does not exist (instead of throwing an exception).
...And 2 more matches

Int64
exceptions thrown typeerror the specified value cannot be converted into a 64-bit integer.
... exceptions thrown typeerror one or both of the specified values is not a 64-bit integer (either signed or unsigned).
... exceptions thrown typeerror num is not a 64-bit integer object.
...And 2 more matches

UInt64
exceptions thrown typeerror the specified value cannot be converted into a 64-bit integer.
... exceptions thrown typeerror one or both of the specified values is not a 64-bit integer (either signed or unsigned).
... exceptions thrown typeerror num is not a 64-bit integer object.
...And 2 more matches

FileEntrySync - Web APIs
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.
...And 2 more matches

IDBRequest.error - Web APIs
in chrome 48+/firefox 58+ this property returns a domexception because domerror has been removed from the dom standard.
...it's an exception type for creating stores and indexes.
... in addition to the error codes sent to the idbrequest object, asynchronous operations can also raise exceptions.
...And 2 more matches

IDBTransactionSync - Web APIs
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.
... 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.
... 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.
...And 2 more matches

XPathEvaluator.evaluate() - Web APIs
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, a domexception of type namespace_error is raised.
...And 2 more matches

XPathExpression.evaluate() - Web APIs
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, a domexception of type namespace_error is raised.
...And 2 more matches

Index - HTTP
with a few exceptions, policies mostly involve specifying server origins and script endpoints.
...when this policy is enabled and there were no user gestures, the promise returned by htmlmediaelement.play() will reject with a domexception.
...when this policy is enabled, the promise returned by navigator.requestmediakeysystemaccess() will reject with a domexception.
...And 2 more matches

handler.setPrototypeOf() - JavaScript
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.
... 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.
...And 2 more matches

core/promise - Archive of obsolete content
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) { // ...
...since a function can either return a value or throw an exception, only one handler will ever be called.
... if handler throws an exception, bar will be rejected with it.
...tion(data) { return writeasync(json.url, data); }); }); in general, nesting is useful for computing values from more than one promise: function eventualadd(a, b) { return a.then(function (a) { return b.then(function (b) { return a + b; }); }); } var c = eventualadd(aasync(), basync()); error handling one sometimes-unintuitive aspect of promises is that if you throw an exception in the value handler, it will not be be caught by the error handler.

io/byte-streams - Archive of obsolete content
if the stream is already closed, an exception is thrown.
...if the stream is closed, an exception is thrown.
...if the stream is already closed, an exception is thrown.
...if the stream is closed, an exception is thrown.

io/text-streams - Archive of obsolete content
if the stream is closed, an exception is thrown.
...if the stream is already closed, an exception is thrown.
...if the stream is closed, an exception is thrown.
...if the stream is already closed, an exception is thrown immediately.

XPCOM Objects - Archive of obsolete content
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.
... 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.
...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.

Beginning our React todo list - Learn web development
</label> </h2> <input type="text" id="new-todo-input" classname="input input__lg" name="text" autocomplete="off" /> <button type="submit" classname="btn btn__primary btn__lg"> add </button> </form> <div classname="filters btn-group stack-exception"> <button type="button" classname="btn toggle-btn" aria-pressed="true"> <span classname="visually-hidden">show </span> <span>all</span> <span classname="visually-hidden"> tasks</span> </button> <button type="button" classname="btn toggle-btn" aria-pressed="false"> <span classname="visually-hidden">show </span> <span>active<...
... <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">...
... 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.
... 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...

NetUtil.jsm
exceptions thrown this method throws an exception with the message "must have a source and a sink" if either asource or asink is null.
... exceptions thrown this method throws an exception with the message "must have a source and a callback" if either asource or acallback is null.
... 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.
... exceptions thrown ns_error_invalid_arg the specified stream is not an nsiinputstream.

JSErrorReport
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_is_exception(flags) returns true if flags has jsreport_exception.
... 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 ...

nsIComponentManager
exceptions thrown ns_error_factory_not_registered indicates that the specified class is not registered.
... exceptions thrown ns_error_factory_not_registered indicates that the specified class is not registered.
... exceptions thrown ns_error_factory_not_registered indicates that the specified class is not registered.
... exceptions thrown ns_error_factory_not_registered indicates that the specified class is not registered.

nsIContentViewer
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 ...
... 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.
...return value missing description exceptions thrown missing exception missing description resetclosewindow() works in tandem with permitunload(), if the caller decides not to close() the window it indicated it will, it is the caller's responsibility to reset that with this method.
...exceptions thrown missing exception missing description native code only!setbounds void setbounds( [const] in nsintrectref abounds ); parameters abounds missing description native code only!setdocumentinternal note: prior to gecko 10.0 (firefox 10.0 / thunderbird 10.0 / seamonkey 2.7), this attribute was part of nsidocumentviewer.

nsICryptoHMAC
exceptions thrown ns_error_not_initialized if init() has not been called.
...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.
... exceptions thrown ns_error_not_initialized if init() has not been called.
... exceptions thrown ns_error_not_initialized if init() has not been called.

nsIDOMMozNetworkStatsManager
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.
... exceptions thrown invalidnetwork the network must be in the return of getavailablenetworks.
... exceptions thrown invalidnetwork the network must be in the return of getavailablenetworks.

nsIDOMNSHTMLDocument
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).
... return value this method is not supported and always throws an exception.
... 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).
... return value this method is not supported and always throws an exception.

nsIHttpChannelInternal
this may throw an ns_error_not_available exception if accessed when the channel's endpoints haven't been determined yet, or any time the nsihttpactivityobserver.isactive attribute is false.
...this may throw an ns_error_not_available exception if accessed when the channel's endpoints haven't been determined yet, or any time the nsihttpactivityobserver.isactive attribute is false.
...this may throw an ns_error_not_available exception if accessed when the channel's endpoints haven't been determined yet, or any time the nsihttpactivityobserver.isactive attribute is false.
...this may throw an ns_error_not_available exception if accessed when the channel's endpoints haven't been determined yet, or any time the nsihttpactivityobserver.isactive attribute is false.

nsIHttpServer
* handler; this path must not include a query string or hash component; it * also should usually be canonicalized, since most browsers will do so * before sending otherwise-matching requests * @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 "/" */ void registerpathhandler(in string path, in nsihttprequesthandler handler); /** * registers a custom prefix 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.
... 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.
... * * @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.

nsILocalFile
exceptions thrown ns_error_file_unrecognized_path indicates that relativefilepath incorrectly begins with a path separator character or otherwise contains invalid characters.
... exceptions thrown ns_error_file_unrecognized_path indicates that relativefilepath incorrectly begins with a path separator character or otherwise contains invalid characters.
... 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.
... 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.

nsIPrincipal
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.
... exceptions thrown ns_error_dom_bad_uri the load is not permitted.
... native code only!iscapabilityenabled boolean iscapabilityenabled( in string capability, in voidptr annotation ); parameters capability missing description annotation missing description return value missing description exceptions thrown missing exception missing description native code only!revertcapability void revertcapability( in string capability, inout voidptr annotation ); parameters capability missing description annotation missing description exceptions thrown missing exception missing description native code only!setcanenablecapability void setcanenablecapability( in ...
...string capability, in short canenable ); parameters capability missing description canenable missing description exceptions thrown missing exception missing description subsumes() returns whether the other principal is equal to or weaker than this principal.

nsIScriptableInputStream
exceptions thrown ns_base_stream_closed if called after the stream has been closed.
...exceptions thrown ns_error_not_initialized if init() was not called.
...this exception may only be thrown if nsiinputstream.isnonblocking() returns true.
...exceptions thrown ns_error_failure if there are not enough bytes available to read acount amount of data.

nsIServiceManager
exceptions thrown ns_error_factory_not_registered indicates that the specified class is not registered.
... exceptions thrown ns_error_factory_not_registered indicates that the specified class is not registered.
... exceptions thrown ns_error_service_not_available indicates that the service hasn't been instantiated.
... exceptions thrown ns_error_service_not_available indicates that the service hasn't been instantiated.

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

ArrayType
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.
... exceptions thrown typeerror length is not provided for unsized array, or is provided for sized array.
...this will throw a typeerror exception if the value can't be converted.
...if this value isn't a valid javascript number that's also a valid index into the array, a typeerror exception is thrown.

StructType
exceptions thrown typeerror the name is not a string, or one or more of the fields does not have a defined size.
... exceptions thrown error fields are not yet defined.
...this will throw a typeerror exception if the value can't be converted.
... exceptions thrown typeerror name is not a javascript string, or doesn't name a member field of the structure.

Web Console remoting - Firefox Developer Tools
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.
... 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.
... 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.

AudioNode.disconnect() - Web APIs
if no matching connection is found, an invalidaccesserror exception is thrown.
...if this parameter is out-of-bound, an indexsizeerror exception is thrown.
... if this parameter is out-of-bound, an indexsizeerror exception is thrown.
... exceptions indexsizeerror a value specified for input or output is invalid, referring to a node which doesn't exist or outside the permitted range.

Cache - Web APIs
the code handles exceptions thrown from the fetch() operation.
... note that an http error response (e.g., 404) will not trigger an exception.
... return response; }); }).catch(function(error) { // this catch() will handle exceptions that arise from the match() or fetch() operations.
...404) will not trigger an exception.

HTMLInputElement - Web APIs
(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.
...(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.
...throws an invalid_state_err exception: if the method is not applicable to for the current type value, if the element has no step value, if the value cannot be converted to a number, if the resulting value is above the max or below the min.
...throws an invalid_state_err exception: if the method is not applicable to for the current type value., if the element has no step value, if the value cannot be converted to a number, if the resulting value is above the max or below the min.

IDBRequest - Web APIs
when the state is still pending, any attempt to access the result or error raises an invalidstateerror exception.
...if an error occurs while performing the operation, the exception is made available through the result property and an error event is fired (idbrequest.onerror).
... idbrequest.error read only returns a domexception in the event of an unsuccessful request, indicating what went wrong.
...if the the request failed and the result is not available, an invalidstateerror exception is thrown.

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.
... 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.
... function recordstream(stream) { let recorder = null; let bufferlist = []; try { recorder = new mediarecorder(stream); } catch(err) { /* exception while trying to create the recorder; handle that */ } recorder.ondataavailable = function(event) { bufferlist.push(event.data); }; recorder.onerror = function(event) { let error = event.error; }; recorder.start(100); /* 100ms time slices per buffer */ return recorder; } specifications specification status comment mediastream recordingthe def...

TextDecoder() - Web APIs
if the value for utflabel is unknown, or is one of the two values leading to a 'replacement' decoding algorithm ( "iso-2022-cn" or "iso-2022-cn-ext"), a domexception with the "typeerror" value is thrown.
...o-2022-kr" 'iso-2022-kr' "utf-16be" 'utf-16be' "utf-16", "utf-16le" 'utf-16le' "x-user-defined" 'x-user-defined' "iso-2022-cn", "iso-2022-cn-ext" 'replacement' optionsoptional is a textdecoderoptions dictionary 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.
... 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.

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
with a few exceptions, policies mostly involve specifying server origins and script endpoints.
...when this policy is enabled, attempting to set document.domain will fail and cause a securityerror domexception to be be thrown.
...when this policy is enabled, the promise returned by navigator.requestmediakeysystemaccess() will reject with a domexception.
...when this policy is enabled, the promise returned by navigator.requestmidiaccess() will reject with a domexception.

Meta programming - JavaScript
the result of object.getownpropertydescriptor(target) can be applied to target using object.defineproperty and will not throw an exception.
... 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.
... in strict mode, a false return value from the set handler will throw a typeerror exception.

Optional chaining (?.) - JavaScript
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).
...do something with the data } catch (err) { onerror?.(err.message); // no exception if onerror is undefined } } optional chaining with expressions you can also use the optional chaining operator when accessing properties with an expression using the bracket notation of the property accessor: let nestedprop = obj?.['prop' + 'name']; optional chaining not valid on the left-hand side of an assignment let object = {}; object?.property = 1; // uncaught syntaxerror: invalid l...

passwords - Archive of obsolete content
the callback is passed an error containing a reason of a failure: this is an nsiexception object.
...the callback is passed an error argument: this is an nsiexception object.
...the callback is passed an error argument: this is an nsiexception object.

url - Archive of obsolete content
if source is not a valid uri, this constructor will throw an exception.
...if is not a valid uri, this constructor will throw an exception.
...an exception is raised if the url can't be converted; otherwise, the native file path is returned as a string.

event/core - Archive of obsolete content
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.

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
error: getldapattibutes failed: [exception...
... error: getldapattibutes failed: [exception...
...how as it been compiled?) about:buildconfig build platform target i686-pc-linux-gnu build tools compiler version compiler flags gcc gcc version 3.4.3 20050227 (red hat 3.4.3-22.fc3) -wall -w -wno-unused -wpointer-arith -wcast-align -wno-long-long -pedantic -pthread -pipe c++ gcc version 3.4.3 20050227 (red hat 3.4.3-22.fc3) -fno-rtti -fno-exceptions -wall -wconversion -wpointer-arith -wcast-align -woverloaded-virtual -wsynth -wno-ctor-dtor-privacy -wno-non-virtual-dtor -wno-long-long -pedantic -fshort-wchar -pthread -pipe -i/usr/x11r6/include configure arguments --disable-mailnews --enable-extensions=cookie,xml-rpc,xmlextras,pref,transformiix,universalchardet,webservices,inspector,gnomevfs,negotiateauth --enable-crypto --disable-composer -...

Embedding Mozilla in a Java Application using JavaXPCOM - Archive of obsolete content
ozilla.getinstance(); greversionrange[] 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.
... if your code cannot find the gre and keeps throwing filenotfoundexceptions 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.

Metro browser chrome tests - Archive of obsolete content
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.

Using Breakpoints in Venkman - Archive of obsolete content
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.

Settings - Archive of obsolete content
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.
...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.

Browser Detection and Cross Browser Support - Archive of obsolete content
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.
...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.

Implementation Status - Archive of obsolete content
3.2.4 node-set binding attributes supported 3.2.5 model item property attributes partial in some cases a loop error can occur on valid bindings 302168; 3.3.1 model supported 3.3.2 instance partial instance element with two child element does not trigger exception 337302; 3.3.3 submission partial no support for @indent and complex schema validation 278761; 278762; 3.3.4 bind partial using the index() function in binds does not work.
...-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 xforms-output-exception unsupported 4.5.6 xforms-submit-error supported 4.5.7 xforms-version-exception unsupported 4.6 event sequencing supported 4.6.1 for input, secret, textarea, range, or upload controls supported 4.6.2 for output controls supported 4.6.3 for select or select1 controls partial 4.6.4 for trigger controls supported 4.6...

Index - MDN Web Docs Glossary: Definitions of Web-related terms
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.
... 444 syntax error codingscripting, glossary, javascript an exception caused by the incorrect use of a pre-defined syntax.

Componentizing our React app - Learn web development
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!
...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.
...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...

What to do and what not to do in Bugzilla
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.
...the exceptions to this rule are platform-specific or compiler-specific bugs.

Examples
this state will propagate to newpomise, and components.utils.reporterror will report all the details of the exception to the console.
...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...
... 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.

Promise.jsm
this may be any value, including undefined, though it is generally an error object, like in exception handling.
...for example, unhandled exceptions in the callbacks cause the new promise to be rejected, even if the original promise is fulfilled.
...although the reason can be undefined, it is generally an error object, like in exception handling.

NSS API Guidelines
there can be legitimate exceptions to this 'make everything opaque' rule.
...exceptions to this include objects which are created on the fly, or as global objects.
... the exception to this global effects rule may be functions which set global state for an application at initialization time.

Scripting Java
java exceptions exceptions thrown by java methods can be caught by javascript code using try...catch statement.
... rhino wraps java exceptions into error objects with the following properties: javaexception: the original exception thrown by the java method rhinoexception: the exception wrapped by the rhino runtime the instanceof operator can be used to query the type of an exception: try { java.lang.class.forname("nonexistingclass"); } catch (e) { if (e.javaexception instanceof java.lang.classnotfoundexception) { print("class not found"); } } rhino also supports an extension to the try...catch statement that allows to define conditional catching of exceptions: function classforname(name) { try { return java.lang.class.forname(name); } catch (e if e.javaexception instanceof java.lang.classnotfoundexception) { print("class " + name + " not found"); } catch...
... (e if e.javaexception instanceof java.lang.nullpointerexception) { print("class name is null"); } } classforname("nonexistingclass"); classforname(null); ...

JSNative
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.
... see also mxr id search for jsnative js::callargs js_reporterror js_reportoutofmemory js_setpendingexception ...

JS_ReportError
this function can also raise a javascript exception which a currently executing script can catch.
...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.

JS_ReportErrorNumber
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.
...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.

JS_ValueToString
if at any point an error or exception occurs, or conversion succeeds, the rest of the steps are skipped.
...on error or exception, it returns null.
... this happens, for example, if v is an object and v.tostring() throws an exception.

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...
...tr1; 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 { ptr = new char[-1]; // oom } catch(...) { delete ptr; } } freeing un-initialized data: prevention be careful when freeing data in catch blocks make sure the try block can’t throw before data is initialized initialize variables when they’re declared; for example, set pointers to null memory leaks usually occur when ...
...code that might throw an exception ...

Using the Places annotation service
however, it is more efficient to just try to do the operation and catch the exception; the extra check requires an additional database lookup (which has higher overhead).
... but then again you won't know if the exception meant that the annotation did not exist or something else is broken.
... the getter functions return only the value of the annotation (with the exception of the c++ getpageannotationbinary and getitemannotationbinary methods which return the mimetype as well).

Setting up the Gecko SDK
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.
...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.

Components.lastResult
this is because failure result codes get converted by xpconnect into exceptions that are thrown into the calling javascript method.
...} catch (e) { // the call threw an exception or a native component returned // a failure code!
... if (e instanceof components.interfaces.nsixpcexception) { // we might do something interesting here with the exception object var rv = e.result; } else { // if we don't know how to handle it then rethrow throw e; } } ...

Components.utils.reportError
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.
... it must be called with one parameter, usually an object which was caught by an exception handler.
... examples usage in an exception handler: try { this.could.raise.an.exception; } catch(e) { components.utils.reporterror(e); // report the error and continue execution } sending debugging messages to the error console: components.utils.reporterror("init() called"); ...

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 interface.components.interfacescomponents.interfaces is a read-only object whose properties are interfaces indexed by their names.components.interfacesbyidcomponents.interfacesbyid is a read-only array of classes indexed by iid.components.issuccesscodedetermines whether a given xpcom return code (that is, an nsresult value) indicates the success or failure of an operation, returning true or false respectively.components.lastresultcomponents.managercomponents.manager is a convenience reflection ...
...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.

mozIStorageService
exceptions thrown ns_error_failure an error occurred attempting to open the database.
...exceptions thrown ns_error_invalid_arg if astoragekey is invalid.
...exceptions thrown ns_error_failure an error occurred attempting to open the database.

nsIAccessibleHyperText
exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree.
... exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree.
... return value missing description exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree.

nsIBrowserSearchService
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.
... exceptions thrown ns_error_failure if newindex is out of bounds, or if engine is hidden.

nsIChannelEventSink
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.
...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.
... 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.

nsIFocusManager
setting this to null or to a non-top-level window throws an ns_error_invalid_arg exception.
...void clearfocus( in nsidomwindow awindow ); parameters awindow exceptions thrown ns_error_invalid_arg if awindow is null.
...exceptions thrown ns_error_invalid_arg if awindow is null.

nsIJumpListBuilder
exceptions thrown ns_error_not_available on all calls if taskbar functionality is not supported by the operating system.
...exceptions thrown ns_error_unexpected on internal errors.
...exceptions thrown ns_error_unexpected on internal errors.

nsIMsgFilter
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.
... throws an exception if the action is not label attribute nsmsglabelvalue label; junkscore attribute long junkscore; strvalue attribute autf8string strvalue; customid // action id if type is custom attribute acstring customid; customaction // custom action associated with customid // (which must be set prior to reading this attribute) readonly attribute nsimsgfiltercustomaction customaction; methods addterm() void nsimsgfilter::addterm ( in nsmsgsearchattribvalue attrib, in nsmsgsearchopvalue op, in nsimsgsearchvalue value, in boolean booleanand, in acstring arbitraryheader ) getterm() void nsimsgfilter::getterm ( in long termindex, in nsmsgsearchattribvalue attrib, in nsmsg...

nsIMsgRuleAction
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.
... throws an exception if the action is not label attribute nsmsglabelvalue label; // junkscore throws an exception if the action type is not junkscore attribute long junkscore; attribute autf8string strvalue; // action id if type is custom attribute acstring customid; // custom action associated with customid // (which must be set prior to reading this attribute) readonly attribute nsimsgfiltercustomaction customaction; }; ...

nsIMutableArray
exceptions thrown ns_error_failure when a weak reference is requested, but the element does not support nsiweakreference.
... exceptions thrown ns_error_failure when a weak reference is requested, but the element does not support nsiweakreference.
... exceptions thrown ns_error_failure when a weak reference is requested, but the element does not support nsiweakreference.

nsISeekableStream
exceptions thrown ns_base_stream_closed if called on a closed stream.
...exceptions thrown ns_base_stream_closed if called on a closed stream.
...exceptions thrown ns_base_stream_closed if called on a closed stream.

nsISessionStore
exceptions thrown this method throws a ns_error_illegal_value exception if the key doesn't exist.
... return value exceptions thrown ns_error_invalid_arg when aindex does not map to a closed window.
... 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".

nsIThread
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.
... exceptions thrown ns_error_unexpected the method was called when this thread wasn't the current thread.
... exceptions thrown ns_error_unexpected this method was called when this thread wasn't the current thread.

nsIToolkitProfileService
exceptions thrown ns_error_unexpected an unexpected error condition occurred.
...exceptions thrown ns_error_out_of_memory an error occurred trying to allocate the memory buffer used to construct the profile list.
...exceptions thrown ns_error_failure no matching profile was found.

nsIWebBrowserPersist
exceptions thrown ns_error_invalid_arg one or more arguments was invalid.
... exceptions thrown ns_error_invalid_arg one or more arguments was invalid.
...all arguments and exceptions are identical to saveuri, with the exception of aisprivate which is used to indicate the private nature of the operation.

nsIWebProgress
exceptions thrown ns_error_failure indicates that there is no associated dom window.
... exceptions thrown ns_error_invalid_arg indicates that alistener was either null or that it does not support weak references.
... exceptions thrown ns_error_failure indicates that alistener was not registered.

nsIXULTemplateQueryProcessor
exceptions thrown ns_error_unexpected if generateresults() has already been called.
...exceptions thrown ns_error_invalid_arg if aquery is invalid.
... exceptions thrown ns_error_invalid_arg if the datasource is not supported.

nsIAbCard/Thunderbird3
exceptions thrown ns_error_not_available<tt> if the named property does not exist.
... exceptions thrown ns_error_not_available<tt> if the named property does not exist.
... exceptions thrown ns_error_illegal_value type not recognized.

XPIDL
attributes support all of the properties of methods with the exception of optional_argc, as this does not make sense for attributes.
...an exception to the above rule is if the parameter has the iid_is property (a special case for some queryinterface-like operations).
...finally, as an exception to everything already mentioned, for attribute getters and setters the jscontext *cx comes before any other arguments.

CData
this will throw a typeerror exception if the value can't be converted.
... if the 8-bit string contains invalid encoded character, a typeerror exception is thrown.
... if the 8-bit string contains invalid encoded character, no exception is thrown.

PointerType
exceptions thrown typeerror thrown if the parameter isn't a ctype.
...if converting the data fails, a typeerror exception is thrown.
...this will throw a typeerror exception if the value can't be converted.

Debugger.Environment - Firefox Developer Tools
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.
... 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.
... this is not an invocation function; if this call would cause debuggee code to run, this call throws a debugger.debuggeewouldrun exception.

Blob.arrayBuffer() - Web APIs
exceptions while this method doesn't throw exceptions, it may reject the promise.
... this can happen, for example, if the reader used to fetch the blob's data throws an exception.
... any exceptions thrown while getting the data will be converted into rejections.

DOMMatrixReadOnly - Web APIs
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).
...otherwise, a typeerror exception is thrown.
...otherwise, a typeerror exception is thrown.

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 ...
... 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 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 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 interne...

HTMLTableRowElement - Web APIs
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.
...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.
... the methods insertcell and deletecell can raise exceptions.

HTMLTableSectionElement - Web APIs
if the given position is greater (or equal as it starts at zero) than the amount of rows in the section, or is smaller than 0, it raises a domexception with the indexsizeerror value.
...if the given position is greater (or equal as it starts at zero) than the amount of rows in the section, or is smaller than -1, it raises a domexception with the indexsizeerror value.
... obsolete the methods insertrow and deleterow can raise exceptions.

Working with the History API - Web APIs
but there is one important exception: after using history.pushstate(), calling history.back() does not raise a popstate event.
...if you pass a state object whose serialized representation is larger than this to pushstate(), the method will throw an exception.
...the new url must be of the same origin as the current url; otherwise, pushstate() will throw an exception.

IDBCursorSync - Web APIs
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.
...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.
... 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
method overview idbdatabasesync open (in domstring name, in domstring description, in optional boolean modifydatabase) raises (idbdatabaseexception); methods open() opens and returns a connection to a database.
... idbdatabasesync open ( in domstring name, in domstring description ) raises (idbdatabaseexception); parameters name the name for the database.
... exceptions this method can raise an idbdatabaseexception with the following codes: non_transient_err if the name parameter is not valid.

IDBIndex.getAll() - Web APIs
if it is lower than 0 or greater than 232-1 a typeerror exception will be thrown.
... exceptions this method may raise a domexception of the following types: exception description transactioninactiveerror this idbindex's transaction is inactive.
... a typeerror exception is thrown if the count parameter is not between 0 and 232-1 included.

IDBIndex.getAllKeys() - Web APIs
if it is lower than 0 or greater than 232-1 a typeerror exception will be thrown.
... exceptions this method may raise a domexception of the following types: exception description transactioninactiveerror this idbindex's transaction is inactive.
... a typeerror exception is thrown if the count parameter is not between 0 and 232-1 included.

IDBObjectStore.getAll() - Web APIs
if it is lower than 0 or greater than 232-1 a typeerror exception will be thrown.
... exceptions this method may raise a domexception of one of the following types: exception description transactioninactiveerror this idbobjectstore's transaction is inactive.
... a typeerror exception is thrown if the count parameter is not between 0 and 232-1 included.

LocalFileSystemSync - Web APIs
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.
... 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.
... exceptions this method can raise a fileexception with the following codes: exception description encoding_err the syntax of the url was invalid.

MediaRecorder.onerror - Web APIs
the error object is of type mediarecordererrorevent, and its error property contains a domexception object that describes the error that occurred.
...this exception can also occur when a request is made on a source that has been deleted or removed.
...it returns either the mediarecorder or the name of the error that occurred if any exceptions are thrown during the setup process.

Node.removeChild() - Web APIs
if child is actually not a child of the element node, the method throws 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'.

PaymentResponse.retry() - Web APIs
the promise is rejected with an appropriate exception value if the payment fails again.
...see the list of exceptions for show() for further details.
... 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(); } await payresponse.complete("success"); } catch(err) { /* handle the exception */ } } examples try { await paymentrequest.retry(errorfields); } catch (domexception err) { ...

RTCPeerConnection.createAnswer() - Web APIs
failurecallback an rtcpeerconnectionerrorcallback which will be passed a single domexception object explaining why the request to create an answer failed.
... exceptions notreadableerror the identity provider wasn't able to provide an identity assertion.
... operationerror generation of the sdp failed for some reason; this is a general failure catch-all exception.

RTCPeerConnection.createOffer() - Web APIs
errorcallback an rtcpeerconnectionerrorcallback which will be passed a single domexception object explaining why the request to create an offer failed.
... exceptions these exceptions are returned by rejecting the returned promise.
... your rejection handler should examine the received exception to determine which occurred.

SVGStyleElement - Web APIs
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.
... 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.
... 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.

SourceBuffer.mode - Web APIs
if you try to set the mode property value to segments when the initial value is sequence, an exception will be thrown.
... 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.

URL() - Web APIs
if the given base url or the resulting url are not valid urls, the javascript typeerror exception is thrown.
... 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.
...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...

Using Web Workers - Web APIs
you can run whatever code you like inside the worker thread, with some exceptions.
...in addition, workers may use xmlhttprequest for network i/o, with the exception that the responsexml and channel attributes on xmlhttprequest always return null.
... 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).

Specificity - CSS: Cascading Style Sheets
the !important exception when an important rule is used on a style declaration, this declaration overrides any other declarations.
...-implications-of-using-important-in-css https://stackoverflow.com/questions/9245353/what-does-important-in-css-mean https://stackoverflow.com/questions/5701149/when-to-use-important-property-in-css https://stackoverflow.com/questions/11178673/how-to-override-important https://stackoverflow.com/questions/2042497/when-to-use-important-to-save-the-day-when-working-with-css the :is() and :not() exceptions the matches-any pseudo-class :is() and the negation pseudo-class :not() are not considered a pseudo-class in the specificity calculation.
...appears on the screen like this: the :where() exception the specificity-adjustment pseudo-class :where() always has its specificity replaced with zero.

Browser detection using the user agent - HTTP
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.
... most browsers set the name and version in the format browsername/versionnumber, with the notable exception of internet explorer.
... blink chrome/xyz rendering engine version most rendering engines put the version number in the renderingengine/versionnumber token, with the notable exception of gecko.

Proxy Auto-Configuration (PAC) file - HTTP
example 2 as above, but use proxy for local servers which are outside the firewall if there are hosts (such as the main web server) that belong to the local domain but are outside the firewall and are only reachable through the proxy server, those exceptions can be handled using the localhostordomainis() function: function findproxyforurl(url, host) { if ( (isplainhostname(host) || dnsdomainis(host, ".mozilla.org")) && !localhostordomainis(host, "www.mozilla.org") && !localhostordoaminis(host, "merchant.mozilla.org") ) { return "direct"; } else { return "proxy w3proxy.mozilla.org:8080; direct"; } } the above example wil...
...l 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.

Iterators and generators - JavaScript
console.log(sequence.next().value); // 2 console.log(sequence.next().value); // 3 console.log(sequence.next().value); // 5 console.log(sequence.next().value); // 8 console.log(sequence.next(true).value); // 0 console.log(sequence.next().value); // 1 console.log(sequence.next().value); // 1 console.log(sequence.next().value); // 2 you can force a generator to throw an exception by calling its throw() method and passing the exception value it should throw.
... this exception will be thrown from the current suspended context of the generator, as if the yield that is currently suspended were instead a throw value statement.
... if the exception is not caught from within the generator, it will propagate up through the call to throw(), and subsequent calls to next() will result in the done property being true.

Inheritance and the prototype chain - JavaScript
the only exception to the getting and setting behavior rules is when there is an inherited property with a getter or a setter.
...// (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.
...it does not throw an exception.

Error - JavaScript
the error object can also be used as a base object for user-defined exceptions.
...for client-side exceptions, see exception handling statements.
...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.

EvalError() constructor - JavaScript
this exception is not thrown by javascript anymore, however the evalerror object remains for compatibility.
...the name of the file containing the code that caused the exception linenumber optional.
... the line number of the code that caused the exception examples evalerror is not used in the current ecmascript specification and will thus not be thrown by the runtime.

Web audio codec guide - Web media technologies
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.
... note: compatibility information described here is generally correct as of the time this article was written; however, there may be caveats and exceptions.
...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.

Introduction to using XPath in JavaScript - XPath
note that, if the xpathexpression contains a namespace prefix, this will result in a domexception being thrown with the code namespace_err.
...mber to a string for display, the xpath interface will not automatically convert the numerical result if the stringvalue property is requested, so the following code will not work: var paragraphcount = document.evaluate('count(//p)', document, null, xpathresult.any_type, null ); alert( 'this document contains ' + paragraphcount.stringvalue + ' paragraph elements' ); instead, it will return an exception with the code ns_dom_type_error.
... 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.

indexed-db - Archive of obsolete content
domexception provides more detailed information about an exception.
... see the domexception documentation.

selection - Archive of obsolete content
setting the selection when there is no current selection throws an exception.
...setting the selection when there is no current selection throws an exception.

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 console.

util/deprecate - Archive of obsolete content
it does not raise an exception, but just displays the error message and continues to execute the function.
... it does not raise an exception, but just displays the error message and returns.

Chrome Authority - Archive of obsolete content
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.
... for example, none of the following code will be matched by the manifest scanner, leading to exceptions at runtime, when the require() call is prohibited from importing the named modules: // all of these will fail!

File I/O - Archive of obsolete content
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.

JavaScript Debugger Service - Archive of obsolete content
note that onerror is called for every exception.
..., 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
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.
...we never use actual tab characters, with the exception of makefiles, which will be covered later on.

Setting up an extension development environment - Archive of obsolete content
you might also want to set dom.report_all_js_exceptions = true.
... see exception logging in javascript for details.

cert_override.txt - Archive of obsolete content
cert_override.txt is a text file generated in the user profile to store certificate exceptions specified by the user.
...since there is no way to add easily an exception in a xulrunner 1.9 project, you can open the page in firefox, accept the certificate, then copy the cert_override.txt to the xulrunner application profile.

XML in Mozilla - Archive of obsolete content
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.

Getting File Information - Archive of obsolete content
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.

Introduction to XUL - Archive of obsolete content
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.
...rare exceptions to this rule are bugs.

Writing Skinnable XUL and CSS - Archive of obsolete content
there is one notable exception to this rule.
...exceptions to this rule must be approved in order to be allowed into the product.

LiveConnect - Archive of obsolete content
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 exceptions how do java and javascript catch exceptions generated by the other party?

Troubleshooting XForms Forms - Archive of obsolete content
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.

Hoisting - MDN Web Docs Glossary: Definitions of Web-related terms
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.

WAI-ARIA basics - Learn web development
we will clearly mention any exceptions to this.
... note: most browsers will throw a security exception if you try to do an xmlhttprequest call from a file:// url, e.g.

Web fonts - Learn web development
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.
...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.

What is a URL? - Learn web development
in practice, there are some exceptions, the most common being a url pointing to a resource that no longer exists or that has moved.
... 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).

Drawing graphics - Learn web development
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.
... 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.

Starting our Svelte Todo list app - Learn web development
</label> </h2> <input type="text" id="todo-0" autocomplete="off" class="input input__lg" /> <button type="submit" disabled="" class="btn btn__primary btn__lg"> add </button> </form> <!-- filter --> <div class="filters btn-group stack-exception"> <button class="btn toggle-btn" aria-pressed="true"> <span class="visually-hidden">show</span> <span>all</span> <span class="visually-hidden">tasks</span> </button> <button class="btn toggle-btn" aria-pressed="false"> <span class="visually-hidden">show</span> <span>active</span> <span class="visually-hidden">tasks</span> </button> <button c...
... 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
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.
...the exception is progress meters, which are guaranteed to fire event_show and event_hide events when they are displayed or hidden.

Browser chrome tests
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.

Cross Process Object Wrappers
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.
...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.

Limitations of chrome scripts
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.
...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.

How to get a stacktrace with WinDbg
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'.
... a: if you see 'int 3' after either of those exceptions, you will need to execute the following commands in windbg.

CustomizableUI.jsm
customizableui will catch exceptions.
... 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.

FileUtils.jsm
starting in gecko 38.0, passing mode_append without mode_truncate will throw an exception.
... starting in gecko 38.0, passing mode_append without mode_truncate will throw an exception.

OS.File for the main thread
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.
...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.

PromiseWorker.jsm
throw new customerror('meow'); } the converted message will be posted back to the main thread, and it will be converted again to error object, with frommsg function specified for the error in exceptionhandlers property.
...myworker.exceptionhandlers['customerror'] = customerror.frommsg; this is seen in a simple demo at github :: promiseworker custom errors demo - worker side setup.

Mozilla DOM Hacking Guide
static nsresult throwjsexception(jscontext *cx, nsresult aresult);: help me!
...a bad conversion exception would be thrown.

A brief guide to Mozilla preferences
the only exception to this is user.js .
...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.

PR_Poll
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.
... pr_poll_except: fd has an exception condition.

Rhino Debugger
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.

Rhino scopes and contexts
remember to put the exit() call in a finally block if you're executing code that could throw an exception.
...any attempt to modify sealed object throws an exception.

Rhino serialization
exceptions will be thrown if foo or foo.prototype cannot be found the scopes used in either scriptableoutputstream or scriptableinputstream.
...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.

Rhino shell
seal(object) seal the specified object so any attempt to add, delete or modify its properties would throw an exception.
... js> runcommand("bad_command", "--bad-arg", opt) js: "<stdin>", line 18: uncaught javascript exception: java.io.ioexception: bad_command: not found js> // passing explicit environment to the system shell js> runcommand("sh", "-c", "echo $env1 $env2", { env: {env1: 100, env2: 200}}) 100 200 0 js> // use args option to provide additional command arguments js> var arg_array = [1, 2, 3, 4]; js> runcommand("echo", { args: arg_array}) 1 2 3 4 0 examples for windows are similar: js> // invoke shell co...

Invariants
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.
... with a few exceptions (known to brendan and probably jst and mrbkap), we never call a jsapi callback with a property locked.

SpiderMonkey Internals
(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.

JS_DefineProperty
(exception: if attrs contains the jsprop_readonly flag, the setter will never be called, as property assignment will fail before it gets that far.
...on error or exception, it returns false.

JS_SetBranchCallback
if the callback raises an exception using js_setpendingexception() and returns js_false, then the javascript engine propagates the exception to the script that was executing at the time.
... if the callback returns js_false without raising an exception, then the javascript engine immediately stops running the script with an uncatchable error.

JS_SetElement
on error or exception, js_setelement returns false.
...on error or exception, js_setelement returns false and the value left in *vp is unspecified.

JS_SetOptions
mxr id search for jsoption_native_branch_callback jsoption_dont_report_uncaught when returning from the outermost api call, prevent uncaught exceptions from being converted to error reports.
... mxr id search for jsoption_dont_report_uncaught jsoption_relimit added in spidermonkey 1.8 throw an exception if a regular expression backtracks more than n3 times, where n is the length of the input string.

JS_ThrowStopIteration
this article covers features introduced in spidermonkey js1.8 throw a stopiteration exception.
...the engine automatically catches the exception and exits the loop.

JS_ValueToNumber
if at any step an error or exception occurs, or conversion succeeds, the rest of the steps are skipped.
...on error or exception, it returns js_false, and the value left in *dp is undefined.

JS_ValueToSource
on error or exception, it returns null.
... this happens, for example, if v is an object and v.tosource() throws an exception.

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...
... 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 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 con...

SpiderMonkey 1.8
the main difference is that js_reportallocationoverflow throws an exception which the application may catch.
... js_throwstopiteration throws the appropriate stopiteration exception object for the given context.

TPS Tests
logger.asserttrue(condition, msg) asserts that condition is true, otherwise an exception is thrown and the test fails.
... logger.assertequal(val1, val2, msg) asserts that val1 is equal to val2, otherwise an exception is thrown and the test fails.

Using components
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.
...] 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] } ...

jsdIStackFrame
setting or getting this attribute on any other context will throw a ns_error_no_interface exception.
...once a jsdistackframe has been invalidated all method and property accesses will throw a ns_error_not_available exception.

nsIAccessibleImage
exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree.
... exceptions thrown ns_error_failure indicates that the accessible is unattached from the accessible tree.

nsIAccessibleSelectable
exceptions thrown ns_error_failure if the specified object is not selectable.
... exceptions thrown ns_error_failure if the specified object is not selectable.

nsIAnnotationService
it throwns an exception if the annotation is not set.
...it throwns an exception if the annotation is not set.

nsIApplicationCacheChannel
exceptions thrown ns_error_already_opened if set after calling asyncopen() on the channel.
...exceptions thrown ns_error_already_opened if set after calling asyncopen() on the channel.

nsIAuthModule
exceptions thrown ns_error_not_implemented if the underlying authentication mechanism does not support security layers.
... exceptions thrown ns_error_not_implemented if the underlying authentication mechanism does not support security layers.

nsIAuthPrompt2
note: this method may throw any exception when the prompt fails to queue, for example because of out-of-memory error.
... note: exceptions thrown from this function will be treated like a return value of false.

nsIBidiKeyboard
exceptions thrown ns_error_failure if no right-to-left keyboards are installed.
... exceptions thrown ns_error_failure if no right-to-left keyboards are installed.

nsIBinaryInputStream
exceptions thrown ns_error_failure if it can't read alength bytes.
... exceptions thrown ns_error_failure if it can't read alength bytes.

nsICacheService
exceptions thrown ns_error_not_implemented this method is deprecated.
... 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.

nsICategoryManager
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.
... exceptions thrown ns_error_not_available indicates that either the category or entry is undefined.

nsIChannel
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.
... exceptions thrown ns_error_in_progress if the channel is reopened.

nsICommandLine
exceptions thrown ns_error_invalid_arg the specified index is out of bounds.
...exceptions thrown ns_error_invalid_arg the specified flag has no value.

nsIConverterOutputStream
a value of 0x0000 will cause an exception to be thrown upon attempts to write unsupported characters.
... exceptions thrown ns_error_loss_of_significant_data if areplacementcharacter is not encodable in the selected character encoding and an attempt is made to write the character.

nsIDOMHTMLTimeRanges
exceptions thrown index_size_err the specified index is not valid.
...exceptions thrown index_size_err the specified index is not valid.

nsIDOMWindowUtils
exceptions thrown ns_error_not_available there is no current inner window displaydpi float the dpi of the display.
...if two or more key_flag_location_* is specified, this method will throw an exception.

nsIDroppedLinkHandler
exceptions thrown missing exception missing description droplink() given a drop event, determines the link being dragged.
... 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.

nsIJetpack
special messages if an exception goes uncaught in the jetpack process, it will be reported to the chrome process via a message with the name core:exception.
... the message comes with one argument, which represents the exception object that was thrown.

nsINavBookmarksService
exceptions thrown invalid argument exception if it can not find a folder with the given id.
... exceptions thrown if anewindex is out of bounds.

nsIProtocolProxyService
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.
... exceptions thrown ns_error_not_available if there is no alternate proxy available.

nsIRequestObserver
note: an exception thrown from onstartrequest has the side-effect of causing the request to be canceled.
...note: an exception thrown from onstoprequest is generally ignored.

nsISHistory
exceptions thrown ns_ok history entry for the index is obtained successfully.
... exceptions thrown ns_error_failure numentries is invalid or out of bounds with the size of history.

nsIScriptError
exceptionflag 0x2 an exception was thrown for this case - exception-aware hosts can ignore this.
...as addon author i would recommend using "chrome javascript" for logging exceptions caused by addon code.

nsIScriptableUnescapeHTML
exceptions thrown ns_error_failure unable to append the text to the element.
... exceptions thrown ns_error_failure unable to convert the string.

nsIStringBundleOverride
an exception is thrown if the key has not been overridden.
... however, no exception is thrown if the original string bundle did not have the key.

nsIUTF8ConverterService
exceptions thrown ns_error_uconv_noconv when there is no decoder for acharset or error code of nsiunicodedecoder in case of conversion failure.
...exceptions thrown ns_error_uconv_noconv when there is no decoder for acharset or error code of nsiunicodedecoder in case of conversion failure.

nsIUUIDGenerator
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.
... exceptions thrown ns_error_failure if a uuid cannot be generated (for example if an underlying source of randomness is not available) example generating a uuid var uuidgenerator = components.classes["@mozilla.org/uuid-generator;1"] .getservice(components.interfaces.nsiuuidgenerator); var uuid = uuidgenerator.generateuuid(); var uuidstring = uuid.tostring(); ...

nsIXmlRpcFault
extensions/xml-rpc/idl/nsixmlrpcclient.idlscriptable an xml-rpc exception.
... xml-rpc server fault codes are returned wrapped in this; access it using nsixpconnect.getpendingexception->data.

nsIZipReader
exceptions thrown ns_error_illegal_value on many but not all invalid apattern values.
...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
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...
... note: the database engine does not support nested transactions, so attempting to start a transaction when one is already active will throw an exception.

Getting Started Guide
nscomptr helps you write code that is leak-proof, exception safe, and significantly less verbose than you would with raw xpcom interface pointers.
...nscomptr is designed to be used with xpcom interfaces, so don't use it with non-interfaces with specific exceptions described below.

Using the Gecko SDK
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).
...(note: nspr is the one exception to this rule.

Index
85 error reporting tools thunderbird currently, thunderbird tends to eat a lot of exceptions.
...bug 493414), but in the meantime, it would be helpful to be able to get useful output on stderr about exceptions, events and pretty-printed objects.

Using tab-modal prompts
es here', input, 'check text, if no text, checkbox is not shown', check]); //this here is just an alert, showing the values of the prompt prompt.alert.apply(null, ['title not shown in modal', 'user clicked ok: ' + ok + '\n' + 'checked: ' + check.value + '\ninput value: ' + input.value]); note: because the prompts are shown in a tab, if the tab is closed while the prompt is open it will throw an exception.
... /* exception: prompt aborted by user undefined:425 */ ...

Declaring and Using Callbacks
k constructor, the second is used as the this parameter: function myjscallback() { alert(this.message); }; var receiver = { message: 'hi there!' }; var callback = funcptrtype(myjscallback, receiver); // alerts with 'hi there' when the callback is invoked if three arguments are passed to the callback constructor, the third argument is used as a sentinel value which the callback returns if an exception is thrown.
... the sentinel value must be convertible to the return type of the callback: function myjscallback() { throw "uh oh"; }; var callback1 = funcptrtype(myjscallback, null, -1); // returns -1 to the native caller when the exception is thrown.

Working with data
note: if type.size is undefined, creating a new object this way will throw a typeerror exception.
...join() will throw an exception if the resulting number exceeds 64 bits in length.

FunctionType
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.
... exceptions thrown typeerror func is not either pointer value or javascript function.

Tutorial: Show Allocations Per Call Path - Firefox Developer Tools
dbg.uncaughtexceptionhook = handleuncaughtexception; // find the current tab's main content window.
... 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.

Debugger.Object - Firefox Developer Tools
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.
...if the referent is not a global object, throw a typeerror exception.

Index - Firefox Developer Tools
118 access debugging in add-ons the following items are accessible in the context of chrome://browser/content/debugger.xul (or, in version 23 beta, chrome://browser/content/devtools/debugger.xul): 119 breaking on 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.

Animation.finish() - Web APIs
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.
... 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.

AudioContext() - Web APIs
exceptions notsupportederror the specified samplerate isn't supported by the context.
... 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".

AudioNode.connect() - Web APIs
otherwise, a notsupportederror exception is thrown.
... exceptions indexsizeerror the value specified as outputindex or inputindex doesn't correspond to an existing input or output.

AudioParam.setValueCurveAtTime() - Web APIs
every value in the array must be a finite number; if any value is nan, infinity, or -infinity, a typeerror exception is thrown.
... exceptions invalidstateerror the specified array of values has fewer than 2 items in it.

AudioWorkletNode.onprocessorerror - Web APIs
this occurs when the underlying audioworkletprocessor behind the node throws an exception in its constructor, the process method, or any user-defined class method.
... once an exception is thrown, the processor (and thus the node) will output silence throughout its lifetime.

CSSPrimitiveValue.getCounterValue() - Web APIs
if this css value doesn't contain a counter value, a domexception is raised.
... exceptions type description domexception an invalid_access_err is raised if the css value doesn't contain a counter value (e.g.

CSSPrimitiveValue.getFloatValue() - Web APIs
if this css value doesn't contain a float value or can't be converted into the specified unit, a domexception is raised.
... 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.

CSSPrimitiveValue.getRGBColorValue() - Web APIs
if this css value doesn't contain a rgb color value, a domexception is raised.
... exceptions type description domexception an invalid_access_err is raised if the attached property can't return an rgb color value (i.e.

CSSPrimitiveValue.getRectValue() - Web APIs
if this css value doesn't contain a rect value, a domexception is raised.
... exceptions type description domexception an invalid_access_err is raised if the css value doesn't contain a rect value.

CSSPrimitiveValue.getStringValue() - Web APIs
if this css value doesn't contain a string value, a domexception is raised.
... exceptions type description domexception an invalid_access_err is raised if the css value doesn't contain a string value.

CSSPrimitiveValue.setFloatValue() - Web APIs
if the property attached to this value can't accept the specified unit or the float value, the value will be unchanged and a domexception will be raised.
... 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.

CSSPrimitiveValue.setStringValue() - Web APIs
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.
... 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.

CanvasCaptureMediaStreamTrack.requestFrame() - Web APIs
syntax stream.requestframe(); return value undefined usage notes there is currently an issue flagged in the specification pointing out that at this time, no exceptions are being thrown if the canvas isn't origin-clean.
... this may change in the future, so it would be wise to plan ahead and watch for exceptions such as securityerror (although the specific error that might be thrown is not mentioned in the spec, this is a likely candidate).

Crypto.getRandomValues() - Web APIs
exceptions this method can throw an exception under error conditions.
... domexception (name: quotaexceedederror) the requested length exceeds 65,536 bytes.

DOMMatrix - Web APIs
otherwise, a typeerror exception is thrown.
...otherwise, a typeerror exception is thrown.

DirectoryReaderSync - Web APIs
if (!data.cmd || data.cmd != 'list') { return; } try { var fs = requestfilesystemsync(temporary, 1024*1024 /*1mb*/); getallentries(fs.root.createreader()); self.postmessage({entries: paths}); } catch (e) { onerror(e); } }; method overview entrysync readentries () raises (fileexception); method readentries() returns a lost of entries from a specific directory.
... entrysync readentries ( ) raises (fileexception); returns parameter none exceptions this method can raise a fileexception with the following codes: exception description not_found_err the directory does not exist.

Document.querySelector() - Web APIs
this string must be a valid css selector string; if it isn't, a syntax_err exception is thrown.
... exceptions syntax_err the syntax of the specified selectors is invalid.

Document.querySelectorAll() - Web APIs
this string must be a valid css selector string; if it's not, a syntaxerror exception is thrown.
... exceptions syntaxerror the syntax of the specified selectors string is not valid.

Document - Web APIs
mozilla also define some non-standard methods: document.execcommandshowhelp()obsolete since gecko 14 this method never did anything and always threw an exception, so it was removed in gecko 14.0 (firefox 14.0 / thunderbird 14.0 / seamonkey 2.11).
... document.querycommandtext()obsolete since gecko 14 this method never did anything but throw an exception, and was removed in gecko 14 (firefox 14 / thunderbird 14 / seamonkey 2.11).

Document Object Model (DOM) - Web APIs
dom interfaces attr cdatasection characterdata childnode comment customevent document documentfragment documenttype domerror domexception domimplementation domstring domtimestamp domstringlist domtokenlist element event eventtarget htmlcollection mutationobserver mutationrecord namednodemap node nodefilter nodeiterator nodelist nondocumenttypechildnode parentnode processinginstruction selection range text textdecoder textencoder timeranges treewalker url window worker xmldocument obsolete do...
...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
exceptions syntaxerror an attempt was made to set outerhtml using an html string which is not valid.
...many browsers will also throw an exception.

Element.querySelector() - Web APIs
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.
... exceptions syntaxerror the specified selectors are invalid.

Element.querySelectorAll() - Web APIs
this string must be a valid css selector string; if it's not, a syntaxerror exception is thrown.
... exceptions syntaxerror the syntax of the specified selectors string is not valid.

Element.requestFullscreen() - Web APIs
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.

Event.initEvent() - Web APIs
— 17notes notes before firefox 17, a call to this method after the dispatching of the event raised an exception instead of doing nothing.ie full support yesopera full support yessafari full support yeswebview android full support yeschrome android full support yesfirefox android ...
...— 17notes notes before firefox 17, a call to this method after the dispatching of the event raised an exception instead of doing nothing.opera android full support yessafari ios full support yessamsung internet android full support yeslegend full support full supportdeprecated.

EventTarget.dispatchEvent() - Web APIs
exceptions exceptions thrown by event handlers are reported as uncaught exceptions.
... the event handlers run on a nested callstack; they block the caller until they complete, but exceptions do not propagate to the caller.

FetchEvent.request - Web APIs
the code also handles exceptions thrown from the serviceworkerglobalscope.fetch operation.
... note that an http error response (e.g., 404) will not trigger an exception.

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 ...
... 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 no support no supportexperimental.

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 ...
... 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 no support no supportexperimental.

HTMLInputElement.stepDown() - Web APIs
if the form control is non time, date, or numeric in nature, and therefore does not support the step attribute (see the list of supported input types in the the table above), or if the step value is set to any, an invalidstateerror exception is thrown.
...throws an invalid_state_err exception: if the method is not applicable to for the current type value, if the element has no step value, if the value cannot be converted to a number, if the resulting value is above the max or below the min.

HTMLMediaElement.play() - Web APIs
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).
... other exceptions may be reported, depending on browser implementation details, media player implementation, and so forth.

HTMLMediaElement - Web APIs
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.
...using any other size results in an exception being thrown.

HTMLSelectElement.add() - Web APIs
exceptions a domerror of the type hierarchyrequesterror if the item passed to the method is an ancestor of the htmlselectelement.
... obsolete the method now throws an not_found_err exception if the item of the before parameter is not a child of this element.

History.pushState() - Web APIs
if you pass a state object whose serialized representation is larger than this to pushstate(), the method will throw an exception.
...the new url must be of the same origin as the current url; otherwise, pushstate() will throw an exception.

History - Web APIs
calling this method to go back beyond the first page in the session history has no effect and doesn't raise an exception.
... calling this method to go forward beyond the most recent page in the session history has no effect and doesn't raise an exception.

IDBDatabase.transaction() - Web APIs
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.
... 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.

IDBFactory.cmp() - Web APIs
this throws an exception if either of the values is not a valid key.
... 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.

IDBObjectStore.getAllKeys() - Web APIs
if it is lower than 0 or greater than 232-1 a typeerror exception will be thrown.
... exceptions this method may raise a domexception of one of the following types: exception description transactioninactiveerror this idbobjectstore's transaction is inactive.

IDBTransaction.commit() - Web APIs
if it is called on a transaction that is not active, it throws an invalidstateerror domexception.
... exceptions exception description invalidstateerror the transaction state is not active.

IDBTransaction.error - Web APIs
in chrome 48+/firefox 58+ this property returns a domexception because domerror has been removed from the dom standard.
...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
an uncaught exception in the request's success/error handler.
... idbtransaction.error read only returns a domexception indicating the type of error that occured when there is an unsuccessful transaction.

KeyframeEffect.setKeyframes() - Web APIs
two exceptional css properties are: float, which must be written as cssfloat since "float" is a reserved word in javascript.
... 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.

LocalFileSystem - Web APIs
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.
... returns void exceptions this method can raise an fileerror with the following code: exception description encoding_err the syntax of the url was invalid.

Location: assign() - Web APIs
if the assignment can't happen because of a security violation, a domexception of the security_error type is thrown.
... if the provided url is not valid, a domexception of the syntax_error type is thrown.

Location: replace() - Web APIs
if the assignment can't happen because of a security violation, a domexception of the security_error type is thrown.
... if the provided url is not valid, a domexception of the syntax_error type is thrown.

MediaDevices.getDisplayMedia() - Web APIs
exceptions rejections of the returned promise are made by passing a domexception error object to the promise's failure handler.
... possible errors are: aborterror an error or failure that doesn't match any of the other exceptions below occurred.

MediaRecorder.start() - Web APIs
exceptions errors that can be detected immediately are thrown as dom exceptions.
...this exception may also be delivered as an error event if the security options for the source media change after recording begins.

MediaRecorderErrorEvent - Web APIs
it is an event object that encapsulates a reference to a domexception describing the error that occurred.
... error read only a domexception containing information about the error that occurred.

MediaSource.duration - Web APIs
exceptions the following exceptions may be thrown when setting a new value for this property.
... exception explanation invalidaccesserror an attempt was made to set a duration value that was negative, or nan.

Capabilities, constraints, and settings - Web APIs
there are exceptions, and we'll get to those shortly.
...if either call to json.parse() throws an exception, handleerror() is called to output the error message to the log.

Navigator.getBattery() - Web APIs
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.
... notallowederror note: no user agent currently throws this exception, but the specification describes the following behaviors: this document is not allowed to use this feature.

Node - Web APIs
in some cases, a particular feature of the base node interface may not apply to one of its child interfaces; in that case, the inheriting node may return null or throw an exception, depending on circumstances.
... for example, attempting to add children to a node type that cannot have children will throw an exception.

NodeIterator.detach() - Web APIs
once this method had been called, calls to other 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.

ParentNode.querySelector() - Web APIs
this string must be a valid compound selector list supported by the browser; if it's not, a syntaxerror exception is thrown.
... exceptions syntaxerror the syntax of the specified selectors string is not valid.

ParentNode.querySelectorAll() - Web APIs
this string must be a valid css selector string; if it's not, a syntaxerror exception is thrown.
... exceptions syntaxerror the syntax of the specified selectors string is not valid.

PaymentRequest.show() - Web APIs
exceptions aborterror the returned promise rejects with an aborterror if the user agent is already showing a payment panel.
... 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.

PaymentResponse.complete() - Web APIs
if an error occurs, the promise instead rejects, returning one of the exceptions listed below.
... exceptions aborterror the document in which the payment request is taking place became inactive while the user interface was shown.

Using the Payment Request API - Web APIs
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.
...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.

RTCError - Web APIs
it's based upon the standard domexception interface that describes general dom errors.
... properties in addition to the properties defined by the parent interface, domexception, rtcerror includes the following properties: errordetail read only a domstring specifying the webrtc-specific error code identifying the type of error that occurred.

RTCIceCandidate.RTCIceCandidate() - Web APIs
if any of the fields is invalid, parsing of the string silently aborts without throwing an exception.
... exceptions typeerror the specified rtcicecandidateinit has values of null in both the sdpmid and sdpmlineindex properties.

RTCIceCandidate.protocol - Web APIs
protocol is null by default if not specified properly in the sdp, but this is an error condition and will result in a thrown exception when you call rtcpeerconnection.addicecandidate().
... note: if protocol is null — and protocol is supported by the user agent — passing the candidate to addicecandidate() will fail, throwing an operationerror exception.

RTCPeerConnection.addIceCandidate() - Web APIs
receives as input a domexception object describing why failure occurred.
... 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.

RTCPeerConnection.getStats() - Web APIs
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.
...the callback receives as input the exception (a domexception object describing the error which occurred.

RTCPeerConnection.setLocalDescription() - Web APIs
it is passed a single domexception object explaining why the request failed.
... 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.

RTCRtpTransceiver.direction - Web APIs
exceptions when setting the value of direction, the following exceptions can occur: invalidstateerror either the receiver's rtcpeerconnection is closed or the rtcrtpreceiver is stopped.
... usage notes setting the direction when you change the value of direction, an invalidstateerror exception will occur if the connection is closed or the receiver is stopped.

RTCRtpTransceiver.setCodecPreferences() - Web APIs
return value undefined exceptions invalidaccesserror the codecs list includes one or more codecs which are not supported by the transceiver.
...if any unsupported codecs are listed, the browser will throw an invalidaccesserror exception when you call this method.

SVGAnimationElement - Web APIs
if there is no current interval, then a domexception with code invalid_state_err is thrown.
...if the simple duration is undefined (e.g., the end time is indefinite), then a domexception with code not_supported_err is raised.

SVGMarkerElement - Web APIs
exceptions: a domexception with code no_modification_allowed_err is raised when the object itself is read only.
... exceptions: a domexception with code no_modification_allowed_err is raised when the object itself is read only.

SVGMatrix - Web APIs
many of svg's graphics operations utilize 2x3 matrices of the form: [a c e] [b d f] which, when expanded into a 3x3 matrix for the purposes of matrix arithmetic, become: [a c e] [b d f] [0 0 1] an svgmatrix object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown.
... 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.

SVGNumber - Web APIs
an svgnumber object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown.
... note: if the svgnumber is read-only, a domexception with the code no_modification_allowed_err is raised on an attempt to change the value.

SVGPreserveAspectRatio - Web APIs
an svgpreserveaspectratio object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown.
... 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.

SensorErrorEvent.SensorErrorEvent() - Web APIs
syntax sensorerrorevent = new sensorerrorevent(type, {error: domexception}); parameters type will always be 'sensorerrorevent'.
... options optional currently only one option is supported: error: an instance of domexception.

SensorErrorEvent.error - Web APIs
the error read-only property of the sensorerrorevent interface returns the domexception object passed in the event's contructor.
... syntax var domexception = sensorerrorevent.error; value a domexception.

ServiceWorkerGlobalScope.onfetch - Web APIs
the code also handles exceptions thrown from the fetch() operation.
... note that an http error response (e.g., 404) will not trigger an exception.

ServiceWorkerGlobalScope - Web APIs
the code also handles exceptions thrown from the fetch() operation.
... note that an http error response (e.g., 404) will not trigger an exception.

SourceBuffer.appendWindowEnd - Web APIs
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 less than or equal to sourcebuffer.appendwindowstart, or nan.

SourceBuffer.appendWindowStart - Web APIs
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 less than 0, or a value greater than or equal to sourcebuffer.appendwindowend.

SourceBuffer.timestampOffset - Web APIs
exceptions the following exceptions may be thrown when setting a new value for this property.
... exception explanation invalidstateerror one or more of the sourcebuffer objects in mediasource.sourcebuffers are being updated (i.e.

SourceBuffer.trackDefaults - Web APIs
exceptions the following exceptions may be thrown when setting a new value for this property.
... exception explanation invalidstateerror one or more of the sourcebuffer objects in mediasource.sourcebuffers are being updated (i.e.

Storage.setItem() - Web APIs
exceptions setitem() may throw an exception if the storage is full.
...(safari sets the quota to 0 bytes in private mode, unlike other browsers, which allow storage in private mode using separate data containers.) hence developers should make sure to always catch possible exceptions from setitem().

Storage Access API - Web APIs
in the case of breakage, site owners have often encouraged users to add their site as an exception or to disable the policy entirely.
...</iframe> the api is designed to limit the potential storage exceptions to origins for which the user has shown an intent to interact.

Writing a WebSocket server in Java - Web APIs
here's an implementation split into parts: import java.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, nos...
...uchalgorithmexception { 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.

Lighting a WebXR setting - Web APIs
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.
...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).

Using the Web Storage API - Web APIs
however, just asserting that that property exists may throw exceptions.
... here is a function that detects whether localstorage is both supported and available: function storageavailable(type) { var storage; try { storage = window[type]; var x = '__storage_test__'; storage.setitem(x, x); storage.removeitem(x); return true; } catch(e) { return e instanceof domexception && ( // everything except firefox e.code === 22 || // firefox e.code === 1014 || // test name field too, because code might not be present // everything except firefox e.name === 'quotaexceedederror' || // firefox e.name === 'ns_error_dom_quota_reached') && // acknowledge quotae...

The structured clone algorithm - Web APIs
things that don't work with structured clone function objects cannot be duplicated by the structured clone algorithm; attempting to throws a data_clone_err exception.
... cloning dom nodes likewise throws a data_clone_err exception.

Web Workers API - Web APIs
you can run whatever code you like inside the worker thread, with some exceptions.
... in addition, workers may use xmlhttprequest for network i/o, with the exception that the responsexml and channel attributes on xmlhttprequest always return null.

How to check the security state of an XMLHTTPRequest over SSL - Web APIs
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.
... try { errorclass = nsserrorsservice.geterrorclass(status); } catch (ex) { //catching security protocol exception errorclass = 'securityprotocol'; } if (errorclass == nsinsserrorsservice.error_class_bad_cert) { errtype = 'securitycertificate'; } else { errtype = 'securityprotocol'; } // nss_sec errors (happen below the base value because of negative vals) if ((status & 0xffff) < math.abs(nsinsserrorsservice.nss_sec_error_base)) { // the bases...

XMLSerializer.serializeToString() - Web APIs
exceptions typeerror the specified rootnode is not a compatible node type.
... 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.

XPathEvaluator.createExpression() - Web APIs
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.
... namespace_err if the expression contains namespace prefixes which cannot be resolved by the specified xpathnsresolver, a domexception of type namespace_error is raised.

XPathResult.iterateNext() - Web APIs
exceptions type_err in case xpathresult.resulttype is not unordered_node_iterator_type or ordered_node_iterator_type, an xpathexception of type type_err is thrown.
... invalid_state_err if the document is mutated since the result was returned, an xpathexception of type invalid_state_err is thrown.

XRSession.updateRenderState() - Web APIs
exceptions this method may throw any of the following exceptions.
... these are true exceptions, since this method does not return a promise.

XRSystem: isSessionSupported() - Web APIs
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.
... 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.

Cognitive accessibility - Accessibility
timed content should also be avoided, with exceptions for non-interactive synchronized media and real-time events.
...the exception to this is preserving data for more than 20 hours when no actions are taken.

Getting Started - Developer guides
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 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.

<input>: The Input (Form Input) element - HTML: Hypertext Markup Language
even if the above attributes are present, with the exception of required, and empty string will not lead to an error.
...aliditystate.typemismatch validitystate.patternmismatch validitystate.toolong validitystate.tooshort validitystate.rangeunderflow validitystate.rangeoverflow validitystate.stepmismatch validitystate.badinput validitystate.valid validitystate.customerror for each of these boolean properties, a value of true indicates that the specified reason validation may have failed is true, with the exception of the valid property, which is true if the element's value obeys all constraints.

<noframes>: The Frame Fallback element - HTML: Hypertext Markup Language
although most commonly-used browsers support frames, there are exceptions, including certain special-use browsers including some mobile browsers, as well as text-mode browsers.
... a <noframes> element can contain any html elements that are allowed within the body of an html document, with the exception of the <frameset> and <frame> elements, since using frames when they aren't supported doesn't make sense.

MIME types (IANA media types) - HTTP
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.
... 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).

Content-Security-Policy - HTTP
with a few exceptions, policies mostly involve specifying server origins and script endpoints.
... 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).

HTTP response status codes - HTTP
this has the same semantics as the 302 found http response code, with the exception that the user agent must not change the http method used: if a post was used in the first request, a post must be used in the second request.
...this has the same semantics as the 301 moved permanently http response code, with the exception that the user agent must not change the http method used: if a post was used in the first request, a post must be used in the second request.

Equality comparisons and sameness - JavaScript
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.
... 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.

Concurrency model and the event loop - JavaScript
legacy exceptions exist like alert or synchronous xhr, but it is considered a good practice to avoid them.
... beware: exceptions to the exception do exist (but are usually implementation bugs, rather than anything else).

Expressions and operators - JavaScript
the sole exceptions to type conversion within comparisons involve the === and !== operators, which perform strict equality and inequality comparisons.
...for example, when catching exceptions, you can branch to different exception-handling code depending on the type of exception thrown.

Grammar and types - JavaScript
an attempt to access an undeclared variable results in a referenceerror exception being thrown: var a; console.log('the value of a is ' + a); // the value of a is undefined console.log('the value of b is ' + b); // the value of b is undefined var b; // this one may puzzle you until you read 'variable hoisting' below console.log('the value of c is ' + c); // uncaught referenceerror: c is not defined let x; console.log('the value of x is ' + x); // the value of x is undefine...
... 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.

Using Promises - JavaScript
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.
... promises solve a fundamental flaw with the callback pyramid of doom, by catching all errors, even thrown exceptions and programming errors.

TypeError: can't access dead object - JavaScript
the javascript exception "can't access dead object" occurs when firefox disallows add-ons to keep strong references to dom objects after their parent document has been destroyed to improve in memory usage and to prevent memory leaks.
... if (components.utils.isdeadwrapper(window)) { // dead } unprivileged code has no access to component.utils and might just be able catch the exception.

TypeError: "x" is not a constructor - JavaScript
the javascript exception "is not a constructor" occurs when there was an attempt to use an object or a variable as a constructor, but that object or variable is not a constructor.
... this is not legal (the promise constructor is not being called correctly) and will throw a typeerror: this is not a constructor exception: return new promise.resolve(true); instead, use the promise.resolve() or promise.reject() static methods: // this is legal, but unnecessarily long: return new promise((resolve, reject) => { resolve(true); }) // instead, return the static method: return promise.resolve(true); return promise.reject(false); ...

Function.prototype.apply() - JavaScript
note: many older browsers—including chrome <17 and internet explorer <9—don't accept array-like objects, and will throw an exception.
...some engines will throw an exception.

InternalError() constructor - JavaScript
the name of the file containing the code that caused the exception linenumber optional.
... the line number of the code that caused the exception examples creating a new internalerror new internalerror("engine failure"); specifications not part of any standard.

Object.assign() - JavaScript
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 successful...
...console.log(target.foo); // 1, exception is thrown here.

Object.prototype.constructor - JavaScript
description all objects (with the exception of objects created with object.create(null)) will have a constructor property.
...*/ } 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.

handler.defineProperty() - JavaScript
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 return value from the defineproperty() handler will throw a typeerror exception.

ReferenceError() constructor - JavaScript
the name of the file containing the code that caused the exception.
...the line number of the code that caused the exception.

TypeError() constructor - JavaScript
the name of the file containing the code that caused the exception linenumber optional optional.
... the line number of the code that caused the exception examples catching a typeerror try { null.f() } catch (e) { console.log(e instanceof typeerror) // true console.log(e.message) // "null has no properties" console.log(e.name) // "typeerror" console.log(e.filename) // "scratchpad/1" console.log(e.linenumber) // 2 console.log(e.columnnumber) // 2 console.log(e.stack) // "@scratchpad/2:2:3\n" } creating a typeerror try { throw new typeerror('hello', "somefile.js", 10) } catch (e) { console.log(e instanceof typeerror) // true console.log(e.message) // "hello" console.log(e.name) // "typeerror" console.log(e.filename) // "somefile.js" console...

TypedArray.prototype.set() - JavaScript
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.
... exceptions a rangeerror, if the offset is set such as it would store beyond the end of the typed array.

URIError() constructor - JavaScript
the name of the file containing the code that caused the exception.
...the line number of the code that caused the exception.

WebAssembly.CompileError() constructor - JavaScript
filename optional the name of the file containing the code that caused the exception.
... linenumber optional the line number of the code that caused the exception.

WebAssembly.LinkError() constructor - JavaScript
filename optional the name of the file containing the code that caused the exception.
... linenumber optional the line number of the code that caused the exception.

WebAssembly.RuntimeError() constructor - JavaScript
filename optional the name of the file containing the code that caused the exception.
... linenumber optional the line number of the code that caused the exception.

WebAssembly.instantiate() - JavaScript
exceptions if either of the parameters are not of the correct type or structure, a typeerror is thrown.
... exceptions if either of the parameters are not of the correct type or structure, a typeerror is thrown.

delete operator - JavaScript
exceptions throws typeerror in strict mode if the property is an own non-configurable property.
...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.

instanceof - JavaScript
examples demonstrating that string and date are of type object and exceptional cases the following code uses instanceof to demonstrate that string and date objects are also of type object (they are derived from object).
... however, objects created with the object literal notation are an exception here: although the prototype is undefined, instanceof object returns true.

typeof - JavaScript
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.
... 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.

yield - JavaScript
throw is used to throw an exception from the generator.
... this halts execution of the generator entirely, and execution resumes in the caller (as is normally the case when an exception is thrown).

Statements and declarations - JavaScript
throw throws a user-defined exception.
... try...catch marks a block of statements to try, and specifies a response, should an exception be thrown.

Strict mode - JavaScript
gnments, which would accidentally create global variables, instead throw an error in strict mode: 'use strict'; // assuming no global variable mistypedvariable exists mistypevariable = 17; // this line throws a referenceerror due to the // misspelling of variable second, strict mode makes assignments which would otherwise silently fail to throw an exception.
...in strict mode assigning to nan throws an exception.

<mstyle> - MathML
it accepts all attributes of all mathml presentation elements with some exceptions and additional attributes listed below.
... 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>.

Same-origin policy - Web security
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.
... these exceptions are nonstandard and unsupported in any other browser.

Cross-domain Content Scripts - Archive of obsolete content
suppose your content script includes a line like: // content-script.js: unsafewindow.mycustomapi = function () {}; if you have included the "cross-domain-content" key, when the page script tries to access mycustomapi this will result in a "permission denied" exception.

self - Archive of obsolete content
the exception is the context-menu module, which still uses postmessage.

Content Scripts - Archive of obsolete content
the exception is the context-menu module, which still uses postmessage.

Module structure of the SDK - Archive of obsolete content
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.

request - Archive of obsolete content
with the exception of response, all of a request object's properties correspond with the options in the constructor.

io/file - Archive of obsolete content
if the directory is not empty, an exception is thrown.

loader/sandbox - Archive of obsolete content
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.

system/unload - Archive of obsolete content
if object does not have the expected destructor method, then an exception is thrown when ensure() is called.

system/xul-app - Archive of obsolete content
with the exception of ids, each of these properties exposes the attribute of the same name on the nsixulappinfo interface.

ui/button/action - Archive of obsolete content
after that, any attempts to access any of its properties or to call any of its methods will throw exceptions.

ui/button/toggle - Archive of obsolete content
after that, any attempts to access any of its properties or to call any of its methods will throw exceptions.

util/match-pattern - Archive of obsolete content
the matchpattern constructor will throw an exception if you try to set any of these flags.

window/utils - Archive of obsolete content
the exception is the windows() function which returns an array of currently opened windows.

Unit Testing - Archive of obsolete content
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.

JS XPCOM - Archive of obsolete content
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|.

Common Pitfalls - Archive of obsolete content
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.

Default Preferences - Archive of obsolete content
doing so will cause mozilla to stop processing your preferences file without any notification, warning, error, or exception.

Jetpack Processes - Archive of obsolete content
core:exception(error) when an exception occurs in a jetpack script and is not caught, this message is sent to the parent.

Appendix F: Monitoring DOM changes - Archive of obsolete content
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.

Getting Started with Firefox Extensions - Archive of obsolete content
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.

Handling Preferences - Archive of obsolete content
{ return this._prefservice.getintpref("extensions.xulschoolhello.message.count"); }, increment : function() { let currentcount = this._prefservice.getintpref("extensions.xulschoolhello.message.count"); this._prefservice.setintpref("extensions.xulschoolhello.message.count", currentcount + 1); } one important thing to keep in mind is that the "get" methods of the service can throw an exception if the preference is not found.

Intercepting Page Loads - Archive of obsolete content
there may be other cases where accessing this property will throw an exception.

Local Storage - Archive of obsolete content
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.

The Box Model - Archive of obsolete content
a common exception to this rule is when your css is directly related to images, where you'll usually handle measurements in pixels (px).

Extensions support in SeaMonkey 2 - Archive of obsolete content
there are exceptions, but these are few and far between.

Tabbed browser - Archive of obsolete content
e as browser var above //can stylize tab like atab.style.backgroundcolor = 'blue'; //can stylize the tab like atab.style.fontcolor = 'red'; var browser = atab.linkedbrowser; //this is the browser within the tab //this is what the example in the previous section gives //end getting other useful stuff } else { components.utils.reporterror('exception: load context not found!!'); //this is likely no big deal as the channel proably has no associated window, ie: the channel was loading some resource.

Notes on HTML Reflow - Archive of obsolete content
there are exceptions to this rule: most notably, html tables may require more than one pass.

Same-origin policy for file: URIs - Archive of obsolete content
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.

Error Console - Archive of obsolete content
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.

Java in Firefox Extensions - Archive of obsolete content
list[0] = mydir; var envconfig = envconfigclass.newinstance(); arglist[1] = envconfig; // call our constructor with our arguments var env = constructor.newinstance(arglist); be aware that liveconnect, while now actively supported by sun has only recently been reimplemented for use in mozilla, so there may still be some bugs (though many prior liveconnect bugs, such as try-catch not catching java exceptions, the failure of auto-converting javascript arrays properly, etc., have now been fixed).

Basics - Archive of obsolete content
exception()this method does stuff.

Twitter - Archive of obsolete content
errorthrown is an exception object, if one was thrown.

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(...

Mozilla Application Framework in Detail - Archive of obsolete content
its ability to render web content correctly is exceptional.

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
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.

Frequently Asked Questions - Archive of obsolete content
for example we support svg exceptions and svgtransform objects.

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
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.

Writing textual data - Archive of obsolete content
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.

Anonymous Content - Archive of obsolete content
exceptions to the rule are noted below.

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...

How to Quit a XUL Application - Archive of obsolete content
components.interfaces.nsiappstartup.eforcequit : components.interfaces.nsiappstartup.eattemptquit; appstartup.quit(quitseverity); } </script> calling this function if there is an uncaught exception, to force the application to quit: <script> try { dosomething(); } catch (e) { quit(true); } </script> the "quit" menuitem should typically prompt the user if there is unsaved data: <menuitem label="quit" oncommand="quit(false);"/> ...

Index - Archive of obsolete content
this content will be copied for each matching result (though see below for an exception) and inserted into the document.

Actions - Archive of obsolete content
this content will be copied for each matching result (though see below for an exception) and inserted into the document.

Multiple Rule Example - Archive of obsolete content
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.

Templates - Archive of obsolete content
there are some small exceptions however.

XPCOM Interfaces - Archive of obsolete content
if you call queryinterface() on an object and the requested interface is not supported by an object, an exception is thrown.

XUL accessibility guidelines - Archive of obsolete content
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.

Building XULRunner with Python - Archive of obsolete content
unhandled exceptions are displayed in the javascript error console which can be opened usingxulrunner -jsconsole.

Archived Mozilla and build documentation - Archive of obsolete content
exception logging in javascript technical review completed.

2006-11-24 - Archive of obsolete content
he is receiving the following error: error: uncaught exception: [exception...

2006-11-24 - Archive of obsolete content
on how to interface with firefox using xpcom on a similar basis to how a developer can with internet explorer through it's com interface tutorals and references related to extension development tutorials on developing extensions which use the third party libraries for firefox references to mozilla api exposed javascript component + xmldocument not accessible a discussion on error: uncaught exception: permission denied to get property xmldocument.textcontent creating xpcom components a good discussion about "components.classes[cid] has no properties" error firefox http explanation about how firefox handles the http aspect meetings none during this week.

NPN_GetURLNotify - Archive of obsolete content
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_PostURLNotify - Archive of obsolete content
description npn_posturlnotify functions identically to npn_posturl, with these exceptions: npn_posturlnotify supports specifying headers when posting a memory buffer.

NPObject - Archive of obsolete content
functions npn_createobject() npn_retainobject() npn_releaseobject() npn_invoke() npn_invokedefault() npn_evaluate() npn_getproperty() npn_setproperty() npn_removeproperty() npn_hasproperty() npn_hasmethod() npn_setexception() see also npclass ...

NPAPI plugin reference - Archive of obsolete content
npn_setexception a plugin can call this function to indicate that a call to one of the plugin's npobjects generated an error.

Using workers in extensions - Archive of obsolete content
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).

Using JavaScript Generators in Firefox - Archive of obsolete content
closegenerator(); // always have an extra yield at the end or you will see stopiteration // exceptions.

Debug - Archive of obsolete content
debug.setnonusercodeexceptions determines whether any try-catch blocks in this scope are to be treated by the debugger as user-unhandled.

Error.number - Archive of obsolete content
example the following example causes an exception to be thrown and displays the error code that is derived from the error number.

New in JavaScript 1.4 - Archive of obsolete content
new features in javascript 1.4 exception handling (throw and try...catch) in operator instanceof operator changed functionality in javascript 1.4 eval() changes (cannot be called indirectly and no longer a method of object) arguments not a property of functions deprecated function.arity in favor of function.length changes to liveconnect ...

New in JavaScript 1.5 - Archive of obsolete content
changed functionality in javascript 1.5 runtime errors are now reported as exceptions.

Reflect.enumerate() - Archive of obsolete content
exceptions a typeerror, if target is not an object.

LiveConnect Reference - Archive of obsolete content
jsexception the public class jsexception extends runtimeexception, and is thrown when javascript returns an error.

JavaArray - Archive of obsolete content
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.

JavaPackage - Archive of obsolete content
for example, the netscape package contains the package netscape.javascript; the netscape.javascript package contains the classes jsobject and jsexception.

Old Proxy API - Archive of obsolete content
if fix() returns undefined, the call throws a typeerror exception.

XForms Custom Controls - Archive of obsolete content
with rare exception, your control should only need to implement the nsixformsuiwidget interface.

Using the Right Markup to Invoke Plugins - Archive of obsolete content
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.

XQuery - Archive of obsolete content
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).

Using the DOM File API in chrome code - Extensions
if you pass a path to the file constructor from unprivileged code (such as web content), an exception will be thrown.

Audio for Web games - Game development
web audio api for games the web audio api is supported across all modern desktop and mobile browsers, with the exception of opera mini.

Base64 - MDN Web Docs Glossary: Definitions of Web-related terms
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.

Localization - MDN Web Docs Glossary: Definitions of Web-related terms
unit of measure (e.g., kilometers in europe, miles in u.s.) text direction (e.g., european languages are left-to-right, arabic right-to-left) capitalization in latin script (e.g., english uses capitals for weekdays, spanish uses lowercase) adaptation of idioms (e.g., "raining cats and dogs" makes no sense when translated literally) use of register (e.g., in japanese respectful speech differs exceptionally from casual speech) number format (e.g., 10 000,00 in germany vs.

Signature (functions) - MDN Web Docs Glossary: Definitions of Web-related terms
a signature can include: parameters and their types a return value and type exceptions that might be thrown or passed back information about the availability of the method in an object-oriented program (such as the keywords public, static, or prototype).

Syntax error - MDN Web Docs Glossary: Definitions of Web-related terms
an exception caused by the incorrect use of a pre-defined syntax.

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
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).

Organizing your CSS - Learn web development
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.

What do common web layouts contain? - Learn web development
there are complex designs and exceptions, of course.

The HTML5 input types - Learn web development
we'll note any exceptions.

Sending form data - Learn web development
no exception.

Styling web forms - Learn web development
they all do, with a strange exception — <input type="submit"> does not inherit from the parent paragraph in chrome.

Document and website structure - Learn web development
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.

Marking up a letter - Learn web development
in general, the letter should be marked up as an organization of headings and paragraphs, with the following exception.

Fetching data from the server - Learn web development
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.

Introduction to the server side - Learn web development
they generally don't use the same programming languages (the exception being javascript, which can be used on the server- and client-side).

TypeScript support in Svelte - Learn web development
replace the content of the filterbutton.svelte file with the following: <!-- components/filterbutton.svelte --> <script lang='ts'> import { filter } from '../types/filter.enum' export let filter: filter = filter.all </script> <div class="filters btn-group stack-exception"> <button class="btn toggle-btn" class:btn__primary={filter === filter.all} aria-pressed={filter === filter.all} on:click={()=> filter = filter.all} > <span class="visually-hidden">show</span> <span>all</span> <span class="visually-hidden">tasks</span> </button> <button class="btn toggle-btn" class:btn__primary={filter === filter.active} aria-pressed={filter === filter.active} o...

Componentizing our Svelte app - Learn web development
add the following content into the file: <script> export let filter = 'all' </script> <div class="filters btn-group stack-exception"> <button class="btn toggle-btn" class:btn__primary={filter === 'all'} aria-pressed={filter === 'all'} on:click={()=> filter = 'all'} > <span class="visually-hidden">show</span> <span>all</span> <span class="visually-hidden">tasks</span> </button> <button class="btn toggle-btn" class:btn__primary={filter === 'active'} aria-pressed={filter === 'active'} on:click={()=> filter = 'a...

Dynamic behavior in Svelte: working with variables and props - Learn web development
update it like this: <div class="filters btn-group stack-exception"> <button class="btn toggle-btn" class:btn__primary={filter === 'all'} aria-pressed={filter === 'all'} on:click={()=> filter = 'all'} > <span class="visually-hidden">show</span> <span>all</span> <span class="visually-hidden">tasks</span> </button> <button class="btn toggle-btn" class:btn__primary={filter === 'active'} aria-pressed={filter === 'active'} on:click={()=> filter = 'a...

Getting started with Vue - Learn web development
public: this directory contains static assets that are published, but not processed by webpack during build (with one exception; index.html gets some processing).

Setting up your own test automation environment - Learn web development
you can retrieve network, command, exception, and selenium logs for every test within your test build.

Chrome Worker Modules
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}.

Mozilla accessibility architecture
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.

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
when the indexing is done, open the log using "window > show view > other > general > error log" and check the summary and look for exceptions.

Interface Compatibility
one exception to this rule is apis which are explicitly shipped with mozilla prefixes as a technology preview.

Commenting IDL for better documentation
if the specified * quote number is invalid, an exception is thrown.

Reviewer Checklist
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.

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...

Limitations of frame scripts
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.

Communicating with frame scripts
the api is mostly symmetrical, with one major exception: frame scripts can send asynchronous or synchronous messages to chrome, but chrome can only send asynchronous messages to content.

Limitations of frame scripts
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.

Performance
under some circumstances it may even cause exceptions when attempting to register something twice under the same id.

Blocked: Custom cookie permission
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
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
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
the linter makes an exception for code that uses string literals that are hard coded in the source code, assuming benevolent developers.

CSS <display-xul> component
inline-grid obsolete since gecko 62 xul inline grid -moz-grid-group obsolete since gecko 62 xul grid group -moz-grid-line obsolete since gecko 62 xul grid line -moz-stack obsolete since gecko 62 xul stack -moz-inline-stack obsolete since gecko 62 xul inline stack -moz-deck obsolete since gecko 62 xul deck -moz-popup obsolete since gecko 62 xul popup all xul display values, with the exception of -moz-box and -moz-inline-box, have been removed in bug 1288572.

Implementing Download Resuming
the server is not using http 1.1), then accessing this attribute will throw an ns_error_not_resumable exception.

AsyncShutdown.jsm
for instance, at the end of phase profilebeforechange, no service is permitted to write to the profile directory (with the exception of telemetry).

DeferredTask.jsm
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.

Downloads.jsm
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.

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.

PerfMeasurement.jsm
page_faults uint64 the number of page exceptions the os handled.

Deferred
although the reason can be undefined, it is generally an error object, like in exception handling.

Deferred
although the reason can be undefined, it is generally an error object, like in exception handling.

Sqlite.jsm
if an exception is thrown by the onrow handler, the exception is logged and processing of subsequent rows occurs as if nothing happened.

XPCOMUtils.jsm
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.

Encodings for localization files
there are a few exceptions, though.

Mozilla Content Localized in Your Language
gender are there exceptions to standard gender conventions within your language?

Localizing with Mozilla Translator
there will be some exceptions.

What every Mozilla translator should know
there is one exception to this process.

Writing localizable code
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.

MathML3Testsuite
this exception also holds for obsolete features (such as macro, mode etc) or for other undefined behaviors (attribute href for example).

Mozilla Port Blocking
515 printer 526 tempo 530 courier 531 chat 532 netnews 540 uucp 556 remotefs 563 nntp+ssl 587 submission 601 syslog 636 ldap+ssl 993 imap+ssl 995 pop3+ssl 2049 nfs 4045 lockd 6000 x11 protocol specific exceptions each protocol handler can override the global blocked ports to allow it's own protocol to function.

Mozilla Web Developer FAQ
html-specific css exceptions do not apply.

Activity Monitor, Battery Status Menu and top
the exception is when the application is closed, in which case it disappears immediately.

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
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.

NSPR's Position On Abrupt Thread Termination
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.

Optimizing Applications For NSPR
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.

Monitors
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.

JSS Provider Notes
the verification is transparent to the application (unless it fails and throws an exception).