RTCPeerConnection: idpvalidationerror event - Web APIs
an idpvalidationerror event informs the target, a rtcpeerconnection object's onidpvalidationerror event handler, that the identity provider (idp) encountered an error while validating an identity assertion.
... an idpvalidationerror event informs the target, a rtcpeerconnection object's onidpvalidationerror event handler, that the identity provider (idp) encountered an error while validating an identity assertion.
...peerconnection object's onidpvalidationerror event handler, that the identity provider (idp) encountered an error while validating an identity assertion.
...tityerrorevent event handler property onidpvalidationerror warning: this event is no longer used; instead, you can detect a validation error by detecting when the promise returned by rtcpeerconnection.peeridentity is rejected.

RTCPeerConnection.onidpassertionerror - Web APIs
the rtcpeerconnection.onidpassertionerror event handler is a property containing the code to execute whent the idpassertionerror event, of type rtcidentityerrorevent, is received by this rtcpeerconnection.
...ent, of type rtcidentityerrorevent, is received by this rtcpeerconnection.
...ned by rtcpeerconnection.peeridentity.
...ax peerconnection.onidpassertionerror = function; values function is the name of a user-defined function, without the () suffix or any parameters, or an anonymous function declaration, such as function(event) {...}.

RTCPeerConnection.onidpvalidationerror - Web APIs
the rtcpeerconnection.onidpvalidationerror event handler is a property containing the code to execute whent the idpvalidationerror event, of type rtcidentityerrorevent, is received by this rtcpeerconnection.
...f type rtcidentityerrorevent, is received by this rtcpeerconnection.
...nection.peeridentity to be rejected.
... peerconnection.onidpvalidationerror = function; values function is the name of a user-defined function, without the () suffix or any parameters, or an anonymous function declaration, such as function(event) {...}.

Sensor.onerror - Web APIs
the onerror eventhandler is called when an error occurs on one of the child interfaces of the sensor interface.
... the onerror eventhandler is called when an error occurs on one of the child interfaces of the sensor interface.
... the onerror eventhandler is called when an error occurs on one of the child interfaces of the sensor interface.
...eventhandler is called when an error occurs on one of the child interfaces of the sensor interface.

SpeechRecognitionError.error - Web APIs
the error read-only property of the speechrecognitionerror interface returns the type of error raised.
... the error read-only property of the speechrecognitionerror interface returns the type of error raised.
... the error read-only property of the speechrecognitionerror interface returns the type of error raised.
...acy or user preference.

SpeechRecognitionError.message - Web APIs
the message read-only property of the speechrecognitionerror interface returns a message describing the error in more detail.
... the message read-only property of the speechrecognitionerror interface returns a message describing the error in more detail.
... the message read-only property of the speechrecognitionerror interface returns a message describing the error in more detail.
... interface was renamed to speechrecognitionerrorevent in the web speech api specification.

WebSocket.onerror - Web APIs
the websocket interface's onerror event handler property is a function which gets called when an error occurs on the websocket.
... the websocket interface's onerror event handler property is a function which gets called when an error occurs on the websocket.
... the websocket interface's onerror event handler property is a function which gets called when an error occurs on the websocket.
...ventlistener().

GeolocationPositionError.code - Web APIs
the geolocationpositionerror.code read-only property is an unsigned short representing the error code.
... the geolocationpositionerror.code read-only property is an unsigned short representing the error code.
...on of the geolocation failed because one or several internal sources of position returned an internal error.

GeolocationPositionError.message - Web APIs
the geolocationpositionerror.message read-only property returns a human-readable domstring describing the details of the error.
... the geolocationpositionerror.message read-only property returns a human-readable domstring describing the details of the error.
... the geolocationpositionerror.message read-only property returns a human-readable domstring describing the details of the error.

HTMLCanvasElement: webglcontextcreationerror event - Web APIs
the webglcontextcreationerror event of the webgl api is fired if the user agent is unable to create a webglrenderingcontext context.
...xt context.
...as = document.getelementbyid('canvas'); canvas.addeventlistener('webglcontextcreationerror', function(e) { console.log(e.statusmessage || 'unknown error'); }, false); var gl = canvas.getcontext('webgl'); // logs statusmessage or "unknown error" if unable to create webgl context specifications specification status comment webgl 1.0the definition of 'webglcontextcreationerror' in that specification.

HTMLMediaElement.onerror - Web APIs
the onerror property of the htmlmediaelement interface is the eventhandler for processing error events.
... the onerror property of the htmlmediaelement interface is the eventhandler for processing error events.
...m of error occurs while attempting to load or perform the media.

Notification.onerror - Web APIs
note: this feature is available in web workers.
... note: this feature is available in web workers.
...error property of the notification interface specifies an event listener to receive error events.

ServiceWorkerContainer.onerror - Web APIs
the onerror property of the serviceworkercontainer interface is an event handler fired whenever an error event occurs in the associated service workers.
... the onerror property of the serviceworkercontainer interface is an event handler fired whenever an error event occurs in the associated service workers.
... the onerror property of the serviceworkercontainer interface is an event handler fired whenever an error event occurs in the associated service workers.

SpeechRecognition.onerror - Web APIs
the onerror property of the speechrecognition interface represents an event handler that will run when a speech recognition error occurs (when the error event fires.) syntax myspeechrecognition.onerror = function() { ...
... the onerror property of the speechrecognition interface represents an event handler that will run when a speech recognition error occurs (when the error event fires.) syntax myspeechrecognition.onerror = function() { ...
...n when a speech recognition error occurs (when the error event fires.) syntax myspeechrecognition.onerror = function() { ...

SpeechSynthesisUtterance.onerror - Web APIs
the onerror property of the speechsynthesisutterance interface represents an event handler that will run when an error occurs that prevents the utterance from being succesfully spoken (when the error event fires.) syntax speechsynthesisutteranceinstance.onerror = function() { ...
...etvoices(); ...
...0; i < voices.length ; i++) { if(voices[i].name === selectedoption) { utterthis.voice = voices[i]; } } synth.speak(utterthis); utterthis.onerror = function(event) { console.log('an error has occurred with the speech synthesis: ' + event.error); } inputtxt.blur(); } specifications specification status comment web speech apithe definition of 'onerror' in that specification.

XMLHttpRequestEventTarget.onerror - Web APIs
the xmlhttprequesteventtarget.onerror is the function called when an xmlhttprequest transaction fails due to an error.
... the xmlhttprequesteventtarget.onerror is the function called when an xmlhttprequest transaction fails due to an error.
... the xmlhttprequesteventtarget.onerror is the function called when an xmlhttprequest transaction fails due to an error.

nsIDOMGeoPositionError
the nsidomgeopositionerror interface represents an error that occurred while performing geolocation operations.
... the nsidomgeopositionerror interface represents an error that occurred while performing geolocation operations.

NDEFReader.onerror - Web APIs
the onerror property of ndefreader interface of the web nfc api is called whenever an error occurs during reading of nfc tags, e.g.
... the onerror property of ndefreader interface of the web nfc api is called whenever an error occurs during reading of nfc tags, e.g.

PaymentValidationErrors - Web APIs
the paymentvalidationerrors dictionary represents objects providing information about any and all errors that occurred while processing a payment request.
... the paymentvalidationerrors dictionary represents objects providing information about any and all errors that occurred while processing a payment request.

SpeechRecognitionErrorEvent.error - Web APIs
the error read-only property of the speechrecognitionerrorevent interface returns the type of error raised.
...acy or user preference.

SpeechRecognitionErrorEvent.message - Web APIs
the message read-only property of the speechrecognitionerrorevent interface returns a message describing the error in more detail.
...peechrecognitionerrorevent interface returns a message describing the error in more detail.

XDomainRequest.onerror - Web APIs
an event handler which is called when an xdomainrequest encounters an error.
... an event handler which is called when an xdomainrequest encounters an error.

onerror - Archive of obsolete content
« xul reference home onerror type: script code this event is sent to an image element when an error occurs loading the image.

onerrorcommand - Archive of obsolete content
« xul reference home onerrorcommand type: script code this event handler is called when an error occurs when selecting a result from the popup.

onerror - Web APIs
the filereader onerror handler receives an event object, not an error object, as a parameter, but an error can be accessed from the filereader object, as instanceoffilereader.error // callback from a <input type="file" onchange="onchange(event)"> function onchange(event) { var file = event.target.files[0]; var reader = new filereader(); reader.onerror = function(event) { alert("failed to read file!\n\n" + reader.error); reader.abort(); // (...does this do anything useful in an onerror handler?) }; reader.readastext(file); } ...

FileHandle.onerror - Web APIs
this feature is non-standard and is not on a standards track.

LockedFile.onerror - Web APIs
this feature is non-standard and is not on a standards track.

Index - Web APIs
22 abstractworker api, abstract, abstractworker, interface, reference, sharedworker, web workers, web workers api, worker the abstractworker interface of the web workers api is an abstract interface that defines properties and methods that are common to all types of worker, including not only the basic worker, but also serviceworker and sharedworker.
...orker, web workers, web workers api, worker the abstractworker interface of the web workers api is an abstract interface that defines properties and methods that are common to all types of worker, including not only the basic worker, but also serviceworker and sharedworker.
...pi, worker the abstractworker interface of the web workers api is an abstract interface that defines properties and methods that are common to all types of worker, including not only the basic worker, but also serviceworker and sharedworker.
...And 91 more matches

Using IndexedDB - Web APIs
osest lower integer and the transaction may not start, nor the upgradeneeded event trigger.
...// don't do this, as the version will be rounded to 2 generating handlers the first thing you'll want to do with almost all of the requests you generate is to add success and error handlers: request.onerror = function(event) { // do something with request.errorcode!
... if everything succeeds, a success event (that is, a dom event whose type property is set to "success") is fired with request as its target.
...And 15 more matches

passwords - Archive of obsolete content
ter the url.
...1.0 401 authorization required server: apache/1.3.27 www-authenticate: basic realm="exampleco login" the corresponding values for the credential (excluding username and password) should be: url: "http://www.example.com" realm: "exampleco login" oncomplete and onerror this api is explicitly asynchronous, so all its functions take two callback functions as additional options: oncomplete and onerror.
...m="exampleco login" the corresponding values for the credential (excluding username and password) should be: url: "http://www.example.com" realm: "exampleco login" oncomplete and onerror this api is explicitly asynchronous, so all its functions take two callback functions as additional options: oncomplete and onerror.
...And 6 more matches

RTCPeerConnection - Web APIs
tively gathering candidates—changes.onidentityresult the rtcpeerconnection.onidentityresult event handler is a property containing the code to execute when the identityresult event, of type rtcidentityevent, is received by this rtcpeerconnection.
...ntityresult the rtcpeerconnection.onidentityresult event handler is a property containing the code to execute when the identityresult event, of type rtcidentityevent, is received by this rtcpeerconnection.
...ing the code to execute when the identityresult event, of type rtcidentityevent, is received by this rtcpeerconnection.
...And 6 more matches

indexed-db - Archive of obsolete content
experimental exposes the indexeddb api to add-ons.
...dow.indexeddb.open("mydatabase"); request.onerror = function(event) { console.log("failure"); }; request.onsuccess = function(event) { console.log("success"); }; because your main add-on code can't access the dom, you can't do this.
...r: the button labeled "add" adds the title of the current tab to a database, while the button labeled "list" lists all the titles in the database.
...And 4 more matches

Using Web Workers - Web APIs
ed), not shared.
...to call many different functions both on the main page and in the worker, you can create a system which groups everything together.
...r class that takes the url of the worker, a default listener, and an error handler, and this class is going to keep track of a list of listeners and help us communicate with the worker: function queryableworker(url, defaultlistener, onerror) { var instance = this, worker = new worker(url), listeners = {}; this.defaultlistener = defaultlistener || function() {}; if (onerror) {worker.onerror = onerror;} this.postmessage = function(message) { worker.postmessage(message); } this.terminate = function() { worker.terminate(); } } then we add the methods of adding/removing listeners: this.addlisteners = function(name, listener) { listeners[name] = listener; } this.removelisteners = function(name) { delete listeners[name]; } her...
...And 4 more matches

constructor - JavaScript
provide your own constructor, then a default constructor will be supplied for you.
...constructor() {} if your class is a derived class, the default constructor calls the parent constructor, passing along any arguments that were provided: constructor(...args) { super(...args); } that enables code like this to work: class validationerror extends error { printcustomermessage() { return `validation failed :-( (details: ${this.message})`; } } try { throw new validationerror("not a valid phone number"); } catch (error) { if (error instanceof validationerror) { console.log(error.name); // this is error instead of validationerror!
...return `validation failed :-( (details: ${this.message})`; } } try { throw new validationerror("not a valid phone number"); } catch (error) { if (error instanceof validationerror) { console.log(error.name); // this is error instead of validationerror!
...And 4 more matches

Optional chaining (?.) - JavaScript
this position as well: someinterface?.custommethod?.() dealing with optional callbacks or event handlers if you use callbacks or fetch methods from an object with a destructuring assignment, you may have non-existent values that you cannot call as functions unless you have tested their existence.
...acks or event handlers if you use callbacks or fetch methods from an object with a destructuring assignment, you may have non-existent values that you cannot call as functions unless you have tested their existence.
...f you use callbacks or fetch methods from an object with a destructuring assignment, you may have non-existent values that you cannot call as functions unless you have tested their existence.
...And 4 more matches

nsIDOMGeoGeolocation
hrows an exception when importing, try using this: var geolocation = components.classes["@mozilla.org/geolocation;1"] .getservice(components.interfaces.nsisupports); method overview void clearwatch(in unsigned short watchid); void getcurrentposition(in nsidomgeopositioncallback successcallback, [optional] in nsidomgeopositionerrorcallback errorcallback, [optional] in nsidomgeopositionoptions options); unsigned short watchposition(in nsidomgeopositioncallback successcallback, [optional] in nsidomgeopositionerrorcallback errorcallback, [optional] in nsidomgeopositionoptions options); attributes attribute ty...
...r.
...lling for new position identifiers and cease invoking callbacks.
...And 3 more matches

JavaScript Debugger Service - Archive of obsolete content
ervice); jsd.on(); // enables the service till firefox 3.6, for 4.x use asyncon if (jsd.ison) jsd.off(); // disables the service hooks jsd operates using the events hook mechanism.
... jsd operates using the events hook mechanism.
...or] returns false jsd.debughook = { onexecute: function(frame, type, rv) { // your function here } }; jsd.enumeratescripts({ // the enumeratescript method will be called once for every script jsd knows about enumeratescript: function(script) { // your function here } }); a simple stack trace here, we will show how to implement a simple javascript stack trace using the jsd.
...And 2 more matches

Application cache implementation overview
st download”.
...cycle is stopped.
...s is passed to the original update via manifestcheckcompleted method.
...And 2 more matches

DOMException - Web APIs
e: not_found_err) notsupportederror the operation is not supported.
... value and constant name).
...t was placed against a transaction that is currently not active or is finished (no legacy code value and constant name).
...And 2 more matches

Client-side storage - Learn web development
e your database (for example, by changing the table structure), you have to run your code again with an increased version number, different schema specified inside the onupgradeneeded handler (see below), etc.
...un your code again with an increased version number, different schema specified inside the onupgradeneeded handler (see below), etc.
...'database failed to open'); }; // onsuccess handler signifies that the database opened successfully request.onsuccess = function() { console.log('database opened successfully'); // store the opened database object in the db variable.
...t entry titleinput.value = ''; bodyinput.value = ''; }; // report on the success of the transaction completing, when everything is done transaction.oncomplete = function() { console.log('transaction completed: database modification finished.'); // update the display of data to show the newly added item, by running displaydata() again.

The Publicity Stream API
ll doable?] the javascript library should be included from: https://myapps.mozillalabs.com/jsapi/publicity.js all apis related to open web applications are accessed under the navigator.apps object.
...publicitystream() and helps determine the results for getuserrecommendedapps().
...server is unreachable activityparseerror - if the activity contains syntax errors (not proper json) invalidactivity - if the activity contains semantic errors (i.e.
... way (please use your own server for any in-app social aspects).

Index
position information is available.
....watchposition().
...com api reference, xpcom interface reference the nsidomgeopositioncoords interface describes a geographical location.
...491 nsidomgeopositionerror dom, geolocation, interfaces, interfaces:scriptable, xpcom, xpcom interface reference the nsidomgeopositionerror interface represents an error that occurred while performing geolocation operations.

FileHandle API - Web APIs
peration always writes content at the end of the file.
...a(); getmeta.onsuccess = function () { var size = this.result.size; // the reading operation will start with the byte at index 0 in the file myfile.location = 0; // start a reading operation for the whole file content var reading = myfile.readastext(size); reading.onsuccess = function () { console.log('the content of the file is:'); console.log(this.result); } reading.onerror = function () { console.log('something goes wrong in the reading process: ' + this.error); } } file snapshot in many cases it can be handy to get a snapshot of the file.
...ar progress = document.queryselector('progress'); var myfile = myfilehandle.open('readonly'); // let's read a 1gb file var action = myfile.readasarraybuffer(1000000000); action.onprogress = function (event) { if (progress) { progress.value = event.loaded; progress.max = event.total; } } action.onsuccess = function () { console.log('yeah \o/ just read a 1gb file'); } action.onerror = function () { console.log('oups :( unable to read a 1gb file') } file storage when a file handle is created, the associated file only exists as a "temporary file" as long as you hold the filehandle instance.
...ill be safe.

IDBDatabase - Web APIs
neventname property of this interface.
...s and error cases, and create a new object store in the case that an upgrade is needed (idbdatabase).
...the task // list with all the to-do list data already in the idb displaydata(); }; // this event handles the event whereby a new version of // the database needs to be created either one has not // been created before, or a new version number has been // submitted via the window.indexeddb.open line above dbopenrequest.onupgradeneeded = function(event) { var db = event.target.result; db.onerror = function(event) { note.innerhtml += '<li>error loading database.</li>'; }; // create an objectstore for this database using // idbdatabase.createobjectstore var objectstore = db.createobjectstore("todolist", { keypath: "tasktitle" }); // define what data items the objectstore will contain objectstore.createindex("hours", "hours", { unique: false }); objectstore.createindex...
... yeschrome android full support 31firefox android full support 50opera android full support yessafari ios full support 10.3samsung internet android full support 2.0onerrorchrome full support 24 full support 24 no support 23 — 24prefixed prefixed implemented with the vendor prefix: webkitedge full support 12firefox full support 16 full support ...

IDBRequest: error event - Web APIs
the error handler is executed when an error caused a request to fail.
...rror examples this example opens a database and tries to add a record, listening for the error event for the add() operation (this will occur if, for example, a record with the given tasktitle already exists): // open the database const dbopenrequest = window.indexeddb.open('todolist', 4); dbopenrequest.addeventlistener('upgradeneeded', event => { const db = event.target.result; db.onerror = () => { console.log('error creating database'); }; // create an objectstore for this database var objectstore = db.createobjectstore('todolist', { keypath: 'tasktitle' }); // define what data items the objectstore will contain objectstore.createindex('hours', 'hours', { unique: false }); objectstore.createindex('minutes', 'minutes', { unique: false }); objectstore.createinde...
...t'], 'readwrite'); const objectstore = transaction.objectstore('todolist'); const newitem = { tasktitle: 'my task', hours: 10, minutes: 10, day: 10, month: 'january', year: 2020 }; const objectstorerequest = objectstore.add(newitem); objectstorerequest.addeventlistener('error', () => { console.log(`error adding new item: ${newitem.tasktitle}`); }); }); the same example, using the onerror property instead of addeventlistener(): // open the database const dbopenrequest = window.indexeddb.open('todolist', 4); dbopenrequest.onupgradeneeded = event => { const db = event.target.result; db.onerror = () => { console.log('error creating database'); }; // create an objectstore for this database var objectstore = db.createobjectstore('todolist', { keypath: 'tasktitle' }); ...
...b = dbopenrequest.result; // open a read/write db transaction, ready for adding the data const transaction = db.transaction(['todolist'], 'readwrite'); const objectstore = transaction.objectstore('todolist'); const newitem = { tasktitle: 'my task', hours: 10, minutes: 10, day: 10, month: 'january', year: 2020 }; const objectstorerequest = objectstore.add(newitem); objectstorerequest.onerror = () => { console.log(`error adding new item: ${newitem.tasktitle}`); }; }; ...

IDBRequest - Web APIs
plain words, all asynchronous methods return a request object.
...factory.open unless an upgrade is needed.
...ese events using addeventlistener() or by assigning an event listener to the oneventname property of this interface.
...ase asynchronously and make a request; onerror and onsuccess functions are included to handle the success and error cases.

RTCDataChannel: error event - Web APIs
a webrtc error event is sent to an rtcdatachannel object's onerror error handler when an error occurs on the data channel.
... a webrtc error event is sent to an rtcdatachannel object's onerror error handler when an error occurs on the data channel.
...information may be output.
...r type has a different set of information output.

RTCPeerConnection.setRemoteDescription() - Web APIs
rror the rtcpeerconnection is closed, or it's in a state which isn't compatible with the specified description's type.
...d description's type.
...dating existing code.
...ss, the successcallback will be called; in case of failure, the errorcallback will be called.

Promises - Archive of obsolete content
r promises, its standard usage is very easy to adapt to a promise-based approach.
... }); let data = resp.target.response; // use the response to construct form data object for the // second request.
...: let addon = yield new promise(accept => addonmanager.getaddonbyid(addon_id, accept)); let dir = yield new promise(accept => addon.getdatadirectory(accept)); xmlhttprequest function request(url, options) { return new promise((resolve, reject) => { let xhr = new xmlhttprequest; xhr.onload = event => resolve(event.target); xhr.onerror = reject; let defaultmethod = options.data ?

Browser Feature Detection - Archive of obsolete content
le cellspacing="0">'); for (i = 0; i < features.length; i++) { if (features[i].supported) document.write('<tr><td>' + features[i].name + '<\/td><td>' + features[i].supported + '<\/td><\/tr>'); else document.write('<tr><td>' + features[i].name + '<\/td><td style="background-color:red">' + features[i].supported + '<\/td><\/tr>'); } document.write('<\/table>'); } var oldonerror = window.onerror; // suppress error messages...
... { if (features[i].supported) document.write('<tr><td>' + features[i].name + '<\/td><td>' + features[i].supported + '<\/td><\/tr>'); else document.write('<tr><td>' + features[i].name + '<\/td><td style="background-color:red">' + features[i].supported + '<\/td><\/tr>'); } document.write('<\/table>'); } var oldonerror = window.onerror; // suppress error messages...
...onerror = null; document.write('<p><b> your browser ' + navigator.useragent + '<\/b><\/p>'); generatereport(document, 'domcore1', 'document'); generatereport(document, 'domcore2', 'document'); generatereport(document, 'domhtml', 'document'); generatereport(document.body.style, 'domcss1', 'document.body.style'); generatereport(document.body.style, 'domcss2', 'document.body.style'); window.onerror = oldonerror; see also browser detection and cross browser support comparison of layout engines web specifications supported in opera 9 what's new in internet explorer 7 (script) original document information author(s): (unknown) last updated date: updated march 16, 2003 copyright information: copyright © 2001-2003 netscape.

nsIMicrosummaryObserver
es.
...updated gets passed to this handler.
...ry ); parameters microsummary the microsummary whose content has just been updated.

nsIUpdateCheckListener
ation.
...mplete() called when the update check is completed.
...request request, [array, size_is(updatecount)] in nsiupdate updates, in unsigned long updatecount ); parameters request the nsixmlhttprequest object handling the update check.

nsIWifiListener
e is implemented by clients interested in receiving notifications when the list of available wifi access points changes.
...ng alen); void onerror(in long error); methods onchange() called when the list of available access points changes.
... available access points changes.

EventSource: error event - Web APIs
the error event of the eventsource api is fired when a connection with an event source fails to be opened.
...ion with an event source fails to be opened.
...ails to be opened.

FileSystemEntry - Web APIs
ame.
...care of the browser-specific prefixes.
...rowser-specific prefixes.

Geolocation API - Web APIs
rning the updated location.
...nposition instance is returned by a successful call to one of the methods contained inside geolocation, inside a success callback, and contains a timestamp plus a geolocationcoordinates object instance.
...ed by a successful call to one of the methods contained inside geolocation, inside a success callback, and contains a timestamp plus a geolocationcoordinates object instance.

IDBDatabase: error event - Web APIs
the error event is fired on idbdatabase when a request returns an error and the event bubbles up to the connection object.
...est.result; db.addeventlistener('error', () => { console.log(`error adding new item: ${newitem.tasktitle}`); }); // open a read/write db transaction, ready for adding the data const transaction = db.transaction(['todolist'], 'readwrite'); const objectstore = transaction.objectstore('todolist'); const objectstorerequest = objectstore.add(newitem); }; the same example, using the onerror property instead of addeventlistener(): // open the database const dbopenrequest = window.indexeddb.open('todolist', 4); dbopenrequest.onupgradeneeded = (event) => { const db = event.target.result; // create an objectstore for this database const objectstore = db.createobjectstore('todolist', { keypath: 'tasktitle' }); // define what data items the objectstore will contain objectsto...
...', { unique: false }); objectstore.createindex('day', 'day', { unique: false }); objectstore.createindex('month', 'month', { unique: false }); objectstore.createindex('year', 'year', { unique: false }); }; dbopenrequest.onsuccess = (event) => { const newitem = { tasktitle: 'my task', hours: 10, minutes: 10, day: 10, month: 'january', year: 2020 }; const db = dbopenrequest.result; db.onerror = () => { console.log(`error adding new item: ${newitem.tasktitle}`); }; // open a read/write db transaction, ready for adding the data const transaction = db.transaction(['todolist'], 'readwrite'); const objectstore = transaction.objectstore('todolist'); const objectstorerequest = objectstore.add(newitem); }; ...

IDBRequest.error - Web APIs
his error, for example, if you try to add a new key that already exists in the record.
...e request failed and the result is not available, the invalidstateerror exception is thrown.
...ate the notified value in the object to "yes" data.notified = "yes"; // create another request that inserts the item // back into the database var updatetitlerequest = objectstore.put(data); // when this new request succeeds, run the displaydata() // function again to update the display updatetitlerequest.onsuccess = function() { displaydata(); }; }; objectstoretitlerequest.onerror = function() { // if an error occurs with the request, log what it is console.log("there has been an error with retrieving your data: " + objectstoretitlerequest.error); }; specifications specification status comment indexed database api 2.0the definition of 'error' in that specification.

IDBTransaction: error event - Web APIs
the error event is fired on idbtransaction when a request returns an error and the event bubbles up to the transaction object.
...odolist'], 'readwrite'); transaction.addeventlistener('error', () => { console.log(`error adding new item: ${newitem.tasktitle}`); }); const objectstore = transaction.objectstore('todolist'); const newitem = { tasktitle: 'my task', hours: 10, minutes: 10, day: 10, month: 'january', year: 2020 }; const objectstorerequest = objectstore.add(newitem); }; the same example, using the onerror property instead of addeventlistener(): // open the database const dbopenrequest = window.indexeddb.open('todolist', 4); dbopenrequest.onupgradeneeded = (event) => { const db = event.target.result; // create an objectstore for this database const objectstore = db.createobjectstore('todolist', { keypath: 'tasktitle' }); // define what data items the objectstore will contain objectsto...
...ore.createindex('day', 'day', { unique: false }); objectstore.createindex('month', 'month', { unique: false }); objectstore.createindex('year', 'year', { unique: false }); }; dbopenrequest.onsuccess = (event) => { const db = dbopenrequest.result; // open a read/write db transaction, ready for adding the data const transaction = db.transaction(['todolist'], 'readwrite'); transaction.onerror = () => { console.log(`error adding new item: ${newitem.tasktitle}`); }; const objectstore = transaction.objectstore('todolist'); const newitem = { tasktitle: 'my task', hours: 10, minutes: 10, day: 10, month: 'january', year: 2020 }; const objectstorerequest = objectstore.add(newitem); }; ...

IDBTransaction - Web APIs
signing an event listener to the oneventname property of this interface.
...tes: 30, day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready to add data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of opening the transaction transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed: database modification finished.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.
... yeschrome android full support yesfirefox android full support 22opera android full support 14safari ios full support 8samsung internet android full support yesonerrorchrome full support 24 full support 24 full support 23prefixed prefixed implemented with the vendor prefix: webkitedge full support 12firefox full support 16 f...

MediaRecorder: error event - Web APIs
the mediarecorder interface's error event is fired when an error occurs: for example because recording wasn't allowed or was attempted using an unsupported codec.
...diarecorder interface's error event is fired when an error occurs: for example because recording wasn't allowed or was attempted using an unsupported codec.
...amples using addeventlistener to listen for error events: async function record() { const stream = await navigator.mediadevices.getusermedia({audio: true}); const recorder = new mediarecorder(stream); recorder.addeventlistener('error', (event) => { console.error(`error recording stream: ${event.error.name}`) }); recorder.start(); } record(); the same, but using the onerror event handler property: async function record() { const stream = await navigator.mediadevices.getusermedia({audio: true}); const recorder = new mediarecorder(stream); recorder.onerror = (event) => { console.error(`error recording stream: ${event.error.name}`) }; recorder.start(); } record(); specifications specification status mediastream recor...

RTCDataChannel - Web APIs
losing property is an eventhandler which specifies a function to be called by the browser when the closing event is received by the rtcdatachannel.
...andler which specifies a function to be called by the browser when the closing event is received by the rtcdatachannel.
... the rtcdatachannel interface sends data across the data channel to the remote peer.

RTCError - Web APIs
erty is a long integer identifying the line number of the sdp on which the syntax error occurred.
...sdp at which the error occurred.
...splayed using a function called showmyalertmessage(), which stands in for whatever output mechanism this code might use.

RTCErrorEvent.error - Web APIs
erty is a long integer identifying the line number of the sdp on which the syntax error occurred.
...sdp at which the error occurred.
...splayed using a function called showmyalertmessage(), which stands in for whatever output mechanism this code might use.

RTCIdentityErrorEvent - Web APIs
the rtcidentityerrorevent interface represents an error associated with the identity provider (idp).
... the rtcidentityerrorevent interface represents an error associated with the identity provider (idp).
...ring giving the url where the user can complete the authentication.

RTCRtpSender.setParameters() - Web APIs
ied; this value is used to ensure that setparameters() can only be called to alter changes made by a specific previous call to getparameters().
... you cannot change the number of encoding options once the sender has been created.
...ncodings has changed from the current list's order.

SpeechRecognition: error event - Web APIs
the error event of the web speech api speechrecognition object is fired when a speech recognition error occurs.
... the error event of the web speech api speechrecognition object is fired when a speech recognition error occurs.
...lable no interface speechrecognitionerrorevent event handler property onerror examples you can use the error event in an addeventlistener method: var recognition = new webkitspeechrecognition() || new speechrecognition(); recognition.addeventlistener('error', function(event) { console.log('speech recognition error detected: ' + event.error'); }); or use the onerror event handler property: recognition.onerror = function(event) { console.log('speech recognition error detected: ' + event.error'); } specifications specification status comment web speech apithe definition of 'speech recognition events' in that specification.

SpeechSynthesisUtterance: error event - Web APIs
the error event of the web speech api speechsynthesisutterance object is fired when an error occurs that prevents the utterance from being succesfully spoken.
...m being succesfully spoken.
...les no cancelable no interface speechsynthesiserrorevent event handler property onerror examples you can use the error event in an addeventlistener method: utterthis.addeventlistener('error', function(event) { console.log('an error has occurred with the speech synthesis: ' + event.error'); }); or use the onerror event handler property: utterthis.onerror = function(event) { console.log('an error has occurred with the speech synthesis: ' + event.error'); } specifications specification status comment web speech apithe definition of 'speech synthesis utterance events' in that specification.

XMLHttpRequest: error event - Web APIs
the error event is fired when the request encountered an error.
...ut class="xhr abort" type="button" name="xhr" value="click to start xhr (abort)" /> </div> <textarea readonly class="event-log"></textarea> css .event-log { width: 25rem; height: 4rem; border: 1px solid black; margin: .5rem; padding: .2rem; } input { width: 11rem; margin: .5rem; } js const xhrbuttonsuccess = document.queryselector('.xhr.success'); const xhrbuttonerror = document.queryselector('.xhr.error'); const xhrbuttonabort = document.queryselector('.xhr.abort'); const log = document.queryselector('.event-log'); function handleevent(e) { log.textcontent = log.textcontent + `${e.type}: ${e.loaded} bytes transferred\n`; } function addlisteners(xhr) { xhr.addeventlistener('loadstart', handleevent); xhr.addeventlistener('load', handleevent); ...
...deventlistener('error', handleevent); xhr.addeventlistener('abort', handleevent); } function runxhr(url) { log.textcontent = ''; const xhr = new xmlhttprequest(); addlisteners(xhr); xhr.open("get", url); xhr.send(); return xhr; } xhrbuttonsuccess.addeventlistener('click', () => { runxhr('https://mdn.mozillademos.org/files/16553/dgszyjnxcaipwzy.jpg'); }); xhrbuttonerror.addeventlistener('click', () => { runxhr('https://somewhere.org/i-dont-exist'); }); xhrbuttonabort.addeventlistener('click', () => { runxhr('https://mdn.mozillademos.org/files/16553/dgszyjnxcaipwzy.jpg').abort(); }); result specifications specification status comment xmlhttprequest living standard ...

Web APIs
rectoryentry filesystemdirectoryreader filesystementry filesystementrysync filesystemfileentry filesystemflags filesystemsync focusevent fontface fontfaceset fontfacesetloadevent formdata formdataentryvalue formdataevent fullscreenoptions g gainnode gamepad gamepadbutton gamepadevent gamepadhapticactuator geolocation geolocationcoordinates geolocationposition geolocationpositionerror geometryutils gestureevent globaleventhandlers gyroscope h htmlanchorelement htmlareaelement htmlaudioelement htmlbrelement htmlbaseelement htmlbasefontelement htmlbodyelement htmlbuttonelement htmlcanvaselement htmlcollection htmlcontentelement htmldlistelement htmldataelement htmldatalistelement htmldetailselement htmldialogelement htmldivelement htmldocument htmlelement htmlembedele...
...flineaudiocontext offscreencanvas orientationsensor oscillatornode overconstrainederror p pagetransitionevent paintworklet pannernode parentnode passwordcredential path2d payererrors paymentaddress paymentcurrencyamount paymentdetailsbase paymentdetailsupdate paymentitem paymentmethodchangeevent paymentrequest paymentrequestevent paymentrequestupdateevent paymentresponse paymentvalidationerrors pbkdf2params performance performanceentry performanceeventtiming performanceframetiming performancelongtasktiming performancemark performancemeasure performancenavigation performancenavigationtiming performanceobserver performanceobserverentrylist performancepainttiming performanceresourcetiming performanceservertiming performancetiming periodicwave permissionstatus permissions photocapa...
...s securitypolicyviolationevent selection sensor sensorerrorevent serviceworker serviceworkercontainer serviceworkerglobalscope serviceworkermessageevent serviceworkerregistration serviceworkerstate shadowroot sharedworker sharedworkerglobalscope slottable sourcebuffer sourcebufferlist speechgrammar speechgrammarlist speechrecognition speechrecognitionalternative speechrecognitionerror speechrecognitionerrorevent speechrecognitionevent speechrecognitionresult speechrecognitionresultlist speechsynthesis speechsynthesiserrorevent speechsynthesisevent speechsynthesisutterance speechsynthesisvoice staticrange stereopannernode storage storageestimate storageevent storagemanager storagequota stylepropertymap stylepropertymapreadonly stylesheet stylesheetlist s...

Audio and Video Delivery - Developer guides
element: <video id="webcam" width="480" height="360"></video> next, if supported connect the webcam source to the video element: if (navigator.mediadevices) { navigator.mediadevices.getusermedia({ video: true, audio: false }) .then(function onsuccess(stream) { var video = document.getelementbyid('webcam'); video.autoplay = true; video.srcobject = stream; }) .catch(function onerror() { alert('there has been a problem retreiving the streams - are you running on file:/// or did you disallow access?'); }); } else { alert('getusermedia is not supported in this browser.'); } to find out more, read our mediadevices.getusermedia page.
... mediarecorder object, take the resulting output and feed it to your audio or video source*.
... data.push(e.data); }; recorder.start(); recorder.onerror = function(e) { throw e.error || new error(e.name); // e.name is ff non-spec } recorder.onstop = function(e) { var audio = document.createelement('audio'); audio.src = window.url.createobjecturl(new blob(data)); } settimeout(function() { rec.stop(); }, 5000); }) .catch(function onerror(error) { console.log(error.message); }); see mediarecorder api for more details.

DOM onevent handlers - Developer guides
'anchoronclick(event)'); log(`changed the property to: <code> ${el.onclick.tostring()} </code>`); log(`now even the html attribute has changed: <code> ${el.getattribute("onclick")} </code><br>`); result for historical reasons, some attributes/properties on the <body> and <frameset> elements instead set event handlers on their parent window object.
...et> elements instead set event handlers on their parent window object.
...ndow object.

Caching compiled WebAssembly modules - WebAssembly
st helper function contained inside instantiatecachedurl() — opendatabase() — creates an object store for storing wasm modules, and also handles clearing out the database if the dbversion is updated; it returns a promise resolving to the new database.
...upindatabase() — provides a simple promise-based operation for looking up the given url in the object store we created above.
...${url} was not found in wasm cache`); } }); } storing and instantiating modules next, we define a function storeindatabase() that fires off an async operation to store a given wasm module in a given database.

Connecting to Remote Content - Archive of obsolete content
json, html and plain text.
...d(null); in this example we demonstrate how to make a xmlhttprequest call in asynchronous mode.

Index - Archive of obsolete content
red in different ways for different xul input elements as listed below: 966 onclick xul attributes, xul reference no summary!
... 966 onclick xul attributes, xul reference no summary!

Monitoring WiFi access points - Archive of obsolete content
netscape.security.privilegemanager.enableprivilege('universalxpconnect'); var d = document.getelementbyid("d"); d.innerhtml = ""; for (var i=0; i<accesspoints.length; i++) { var a = accesspoints[i]; d.innerhtml += "<p>" + a.mac + " " + a.ssid + " " + a.signal + "</p>"; } var c = document.getelementbyid("c"); c.innerhtml = "<p>" + count++ + "</p>"; }, onerror: function (value) { alert("error: " +value); }, queryinterface: function(iid) { netscape.security.privilegemanager.enableprivilege('universalxpconnect'); if (iid.equals(components.interfaces.nsiwifilistener) || iid.equals(components.interfaces.nsisupports)) return this; throw components.results.ns_error_no_interface; }, } netscape.se...
... onchange() method (lines 13 through 27) begins by enabling universalxpconnect privileges, then clearing out the div (d) that will receive the updated list of access points.

Index - Archive of obsolete content
el xul attributes, xul reference no summary!
...logdisclosure xul attributes, xul reference no summary!

Textbox (XPFE autocomplete) - Archive of obsolete content
search, autocompletesearchparam, autofill, autofillaftermatch, autofill, completedefaultindex, crop, disableautocomplete, disableautocomplete, disabled, disablehistory, enablehistory, focused, forcecomplete, forcecomplete, highlightnonmatches, ignoreblurwhilesearching, ignoreblurwhilesearching, inputtooltiptext, label, maxlength, maxrows, minresultsforpopup, minresultsforpopup, nomatch, onchange, onerrorcommand, oninput, onsearchcomplete, ontextcommand, ontextentered, ontextrevert, ontextreverted, open, readonly, searchsessions, showcommentcolumn, showcommentcolumn, showpopup, size, tabindex, tabscrolling, tabscrolling, timeout, type, useraction, value properties accessible, alwaysopenpopup, autofill, autofillaftermatch, completedefaultindex, crop, disableautocomplete, disabled, e...
... id="findfile-window" title="find files" orient="horizontal" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"> <script type="text/javascript"> function myfunction(e){ /* do something cool here or just say the below */ alert(e.target.nodename); } </script> <textbox id="find-text" onchange="return myfunction(event);"/> </window> onerrorcommand type: script code this event handler is called when an error occurs when selecting a result from the popup.

image - Archive of obsolete content
e src attribute can be used to specify the url of the image.
...mum sizes using maxheight or maxwidth.

HTMLIFrameElement.download()
warning: removed in firefox 65.
...cified, the filename used will be the original filename, as specified in the url.

HTMLIFrameElement.getContentDimensions()
eelement interface retrieves the x and y dimensions of the content window.
...handles the failure case.

HTMLIFrameElement.purgeHistory()
elete cookies for a firefox os app, you could call clearbrowserdata() on the actual app itself.
...object that returns an onsuccess handler if the history is deleted, or an onerror handler if not.

Assert.jsm
undefined less(lhs, rhs, message); undefined lessorequal(lhs, rhs, message); undefined setreporter(reporterfunc); undefined report(failed, actual, expected, message, operator); constructor creates a new assert object.
...ndler function.

L20n Javascript API
xisting translations are buggy.
...the context instance can recover gracefully and try to fetch a translations from a fallback locale.

JS_SetErrorReporter
reporting function.
...} void onerror(const std::string& error) { // handle error } static void dispatcherror( jscontext* ctx, const char* message, jserrorreport* report) { auto rt = js_getruntime(ctx); auto rt_userdata = js_getruntimeprivate(rt); if (rt_userdata) { auto req = static_cast<myrequest*>(rt_userdata); req->onerror(message); } } }; see also mxr id search for js_geterrorreporter mxr id search for js_seterrorreporter bug 1277278 - js_seterrorreporter is renamed to js::setwarningreporter ...

nsIXMLHttpRequest
rface, as seen below in example 2, we can get access to this.
...f nsixmlhttprequest implements the interface nsidomeventtarget and that's how you're supported to add event listeners.

Clipboard.write() - Web APIs
key of the object passed to the clipboarditem constructor indicates the content type, the value indicates the content.
...then write() is called, specifying both a fulfilment function and an error function.

DirectoryReaderSync - Web APIs
m urls.
...error(e) { postmessage('error: ' + e.tostring()); } self.onmessage = function(e) { var data = e.data; // ignore everything else except our 'list' command.

Document - Web APIs
art event is sent, indicating that a css animation has started playing.
...nt, indicating that a css animation has started playing.

FileReader - Web APIs
has been completed.
...ional encoding name can be specified.

FileSystemDirectoryEntry - Web APIs
esystem || window.webkitrequestfilesystem; window.directoryentry = window.directoryentry || window.webkitdirectoryentry; ...
... function onfs(fs){ fs.root.getdirectory('documents', {create:true}, function(directoryentry){ //directoryentry.isfile === false //directoryentry.isdirectory === true //directoryentry.name === 'documents' //directoryentry.fullpath === '/documents' }, onerror); } // opening a file system with temporary storage window.requestfilesystem(temporary, 1024*1024 /*1mb*/, onfs, onerror); properties this interface has no properties of its own, but inherits properties from its parent interface, filesystementry.

GlobalEventHandlers - Web APIs
art event is sent, indicating that a css animation has started playing.
...nt, indicating that a css animation has started playing.

HTMLBodyElement - Web APIs
s not handled.
...his interface.

HTMLScriptElement - Web APIs
script> that hosts the following code (through document.currentscript).
... = url; } this next function, instead of prepending the new scripts immediately before the document.currentscript element, appends them as children of the <head> tag.

IDBDatabase.onabort - Web APIs
the onabort event handler of the idbdatabase interface handles the abort event, fired when a transaction is aborted and bubbles up to the connection object.
...to the connection object.

IDBDatabase.onversionchange - Web APIs
abase) was requested elsewhere (most probably in another window/tab on the same computer).
...abase.onversionchange = function(event) { ...

IDBObjectStore.createIndex() - Web APIs
g used to update the database structure if a database with a higher version number is loaded.
...with // all the to-do list data already in the idb displaydata(); }; // this handler fires when a new database is created and indicates // either that one has not been created before, or a new version // was submitted with window.indexeddb.open().

IDBObjectStore.deleteIndex() - Web APIs
eindex is used to create new indexes on the object store, after which we delete the unneeded old indexes with deleteindex().
...to-do list data already in the idb displaydata(); }; // this event handles the event whereby a new version of the database needs to be created // either one has not been created before, or a new version number has been submitted via the // window.indexeddb.open line above //it is only implemented in recent browsers dbopenrequest.onupgradeneeded = function(event) { var db = this.result; db.onerror = function(event) { note.innerhtml += '<li>error loading database.</li>'; }; // create an objectstore for this database var objectstore = db.createobjectstore("todolist", { keypath: "tasktitle" }); // define what data items the objectstore will contain objectstore.createindex("hours", "hours", { unique: false }); objectstore.createindex("minutes", "minutes", { unique: false...

IDBObjectStore - Web APIs
; // store the result of opening the database in db.
...s: 19, minutes: 30, day: 24, month: 'december', year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of the transaction completing, when everything is done transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.

IDBOpenDBRequest: blocked event - Web APIs
a versionchange transaction on the same database.
...ion const req2 = indexeddb.open('todolist', 5); // in this case the onblocked handler will be executed req2.addeventlistener('blocked', () => { console.log('request was blocked'); }); }; using the onblocked property: // open the database const dbopenrequest = window.indexeddb.open('todolist', 4); dbopenrequest.onupgradeneeded = (event) => { const db = event.target.result; db.onerror = () => { console.log('error creating database'); }; // create an objectstore for this database var objectstore = db.createobjectstore('todolist', { keypath: 'tasktitle' }); // define what data items the objectstore will contain objectstore.createindex('hours', 'hours', { unique: false }); objectstore.createindex('minutes', 'minutes', { unique: false }); objectstore.createinde...

IDBOpenDBRequest.onblocked - Web APIs
atabase is still in use (that is, not closed) somewhere, even after the versionchange event was sent.
...list data already in the idb displaydata(); }; // this event handles the event whereby a new version of the // database needs to be created.

IDBOpenDBRequest.onupgradeneeded - Web APIs
) var db; // request version 3 of the database.
... var yearindex = bookstore.createindex("by_year", "year"); } if (event.oldversion < 3) { // version 3 introduces a new object store for magazines with two indexes.

IDBOpenDBRequest - Web APIs
ing example you can see the onupgradeneeded handler being used to update the database structure if a database with a higher version number is loaded.
...o list data already in the idb displaydata(); }; // this event handles the event whereby a new version of // the database needs to be created either one has not // been created before, or a new version number has been // submitted via the window.indexeddb.open line above // it is only implemented in recent browsers dbopenrequest.onupgradeneeded = function(event) { var db = this.result; db.onerror = function(event) { note.innerhtml += '<li>error loading database.</li>'; }; // create an objectstore for this database var objectstore = db.createobjectstore("todolist", { keypath: "tasktitle" }); // define what data items the objectstore will contain objectstore.createindex("hours", "hours", { unique: false }); objectstore.createindex("minutes", "minutes", { unique: false...

IDBRequest: success event - Web APIs
bubbles no cancelable no interface event event handler property onsuccess examples this example tries to open a database and listens for the success event using addeventlistener(): // open the database const openrequest = window.indexeddb.open('todolist', 4); openrequest.onupgradeneeded = (event) => { const db = event.target.result; db.onerror = () => { console.log('error creating database'); }; // create an objectstore for this database var objectstore = db.createobjectstore('todolist', { keypath: 'tasktitle' }); // define what data items the objectstore will contain objectstore.createindex('hours', 'hours', { unique: false }); objectstore.createindex('minutes', 'minutes', { unique: false }); objectstore.createinde...
...jectstore.createindex('year', 'year', { unique: false }); }; openrequest.addeventlistener('success', (event) => { console.log('database opened successfully!'); }); the same example, but using the onsuccess event handler property: // open the database const openrequest = window.indexeddb.open('todolist', 4); openrequest.onupgradeneeded = (event) => { const db = event.target.result; db.onerror = () => { console.log('error creating database'); }; // create an objectstore for this database var objectstore = db.createobjectstore('todolist', { keypath: 'tasktitle' }); // define what data items the objectstore will contain objectstore.createindex('hours', 'hours', { unique: false }); objectstore.createindex('minutes', 'minutes', { unique: false }); objectstore.createinde...

IDBTransaction: abort event - Web APIs
ardware failure) quota exceeded.
...ort` transaction.addeventlistener('abort', () => { console.log('transaction was aborted'); }); // abort the transaction transaction.abort(); }; the same example, but assigning the event handler to the onabort property: // open the database const dbopenrequest = window.indexeddb.open('todolist', 4); dbopenrequest.onupgradeneeded = event => { const db = event.target.result; db.onerror = () => { console.log('error creating database'); }; // create an objectstore for this database var objectstore = db.createobjectstore('todolist', { keypath: 'tasktitle' }); // define what data items the objectstore will contain objectstore.createindex('hours', 'hours', { unique: false }); objectstore.createindex('minutes', 'minutes', { unique: false }); objectstore.createinde...

IDBTransaction: complete event - Web APIs
ete handler is executed when a transaction successfully completed.
...ansaction.objectstore('todolist'); const newitem = { tasktitle: 'my task', hours: 10, minutes: 10, day: 10, month: 'january', year: 2019 }; const objectstorerequest = objectstore.add(newitem); }; using the oncomplete property: // open the database const dbopenrequest = window.indexeddb.open('todolist', 4); dbopenrequest.onupgradeneeded = event => { const db = event.target.result; db.onerror = () => { console.log('error creating database'); }; // create an objectstore for this database var objectstore = db.createobjectstore('todolist', { keypath: 'tasktitle' }); // define what data items the objectstore will contain objectstore.createindex('hours', 'hours', { unique: false }); objectstore.createindex('minutes', 'minutes', { unique: false }); objectstore.createinde...

IDBTransaction.error - Web APIs
ished, is finished and successfully committed, or was aborted with the idbtransaction.abort method.
... day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of opening the transaction transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed: database modification finished.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error: ' + transaction.error + '</li>'; }; // create an object store on the transaction var objectstore = transaction.objectstore("todolist"); // add our newitem object to the object store var objectstorerequest = objectstore.add(newitem[0]); objectstorerequest.onsuccess = function(event) { // report t...

MediaRecorder.start() - Web APIs
tion is recorded into a single blob unless the requestdata() method is called to obtain the blob and trigger the creation of a new blob into which the media continues to be recorded.
... called to obtain the blob and trigger the creation of a new blob into which the media continues to be recorded.

MediaRecorder - Web APIs
ilable called to handle the dataavailable event, which is periodically triggered each time timeslice milliseconds of media have been recorded (or when the entire media has been recorded, if timeslice wasn't specified).
...dia recording ends, either when the mediastream ends — or after the mediarecorder.stop() method is called.

MediaRecorderErrorEvent.error - Web APIs
ead-only error property in the mediarecordererrorevent interface is a domexception object providing details about the exception that was thrown by a mediarecorder instance.
...ven mediastream, configured to buffer data into an array and to watch for errors.

Recording a media element - Web APIs
tion handles starting the recording process: function startrecording(stream, lengthinms) { let recorder = new mediarecorder(stream); let data = []; recorder.ondataavailable = event => data.push(event.data); recorder.start(); log(recorder.state + " for " + (lengthinms/1000) + " seconds..."); let stopped = new promise((resolve, reject) => { recorder.onstop = resolve; recorder.onerror = event => reject(event.name); }); let recorded = wait(lengthinms).then( () => recorder.state == "recording" && recorder.stop() ); return promise.all([ stopped, recorded ]) .then(() => data); } startrecording() takes two input parameters: a mediastream to record from and the length in milliseconds of the recording to make.
...he event handler simply pushes the blob onto the data array.

RTCPeerConnection.createAnswer() - Web APIs
iscouraged.
...ribing the newly-created answer.

RTCPeerConnection.createOffer() - Web APIs
gly discouraged.
...urned promise.

RTCPeerConnection.setLocalDescription() - Web APIs
e parameters for the older form of setlocaldescription() are described below, to aid in updating existing code.
...ccesscallback will be called; in case of failure, the errorcallback will be called.

Sensor APIs - Web APIs
ming requires three strategies.
...o use the sensor.

Using server-sent events - Web APIs
enerated.
...o event type) is sent.

WebGLContextEvent.statusMessage - Web APIs
the read-only webglcontextevent.statusmessage property contains additional event status information, or is an empty string if no additional information is available.
...nt status information, or is an empty string if no additional information is available.

WebRTC API - Web APIs
sters an identity provider (idp).
...der (idp).

WebSocket - Web APIs
pen 1 websocket.closing 2 websocket.closed 3 properties websocket.binarytype the binary data type used by the connection.
...itted.

Using the Web Speech API - Web APIs
ch was recognised that wasn't in the defined grammar, or an error occured.
...o be supposed to handle the first case mentioned, although note that at the moment it doesn't seem to fire correctly; it just returns whatever was recognised anyway: recognition.onnomatch = function(event) { diagnostic.textcontent = 'i didnt recognise that color.'; } speechrecognition.onerror handles cases where there is an actual error with the recognition successfully — the speechrecognitionerror.error property contains the actual error returned: recognition.onerror = function(event) { diagnostic.textcontent = 'error occurred in recognition: ' + event.error; } speech synthesis speech synthesis (aka text-to-speech, or tts) involves receiving synthesising text contained within an app to speech, and playing it out of a device's speaker or audio output connection.

Window - Web APIs
event handler property for change events on the window.
...windoweventhandlers.onunload called when the user navigates away from the page.

XDomainRequest - Web APIs
specifing the method (get/post) and url.
...xdomainrequest.onerror a handler for when a request has errored.

Synchronous and asynchronous requests - Web APIs
ile your request is being handled.
...ead file to a specified listener.

XMLHttpRequest: abort event - Web APIs
ut class="xhr abort" type="button" name="xhr" value="click to start xhr (abort)" /> </div> <textarea readonly class="event-log"></textarea> css .event-log { width: 25rem; height: 4rem; border: 1px solid black; margin: .5rem; padding: .2rem; } input { width: 11rem; margin: .5rem; } js const xhrbuttonsuccess = document.queryselector('.xhr.success'); const xhrbuttonerror = document.queryselector('.xhr.error'); const xhrbuttonabort = document.queryselector('.xhr.abort'); const log = document.queryselector('.event-log'); function handleevent(e) { log.textcontent = log.textcontent + `${e.type}: ${e.loaded} bytes transferred\n`; } function addlisteners(xhr) { xhr.addeventlistener('loadstart', handleevent); xhr.addeventlistener('load', handleevent); ...
...deventlistener('error', handleevent); xhr.addeventlistener('abort', handleevent); } function runxhr(url) { log.textcontent = ''; const xhr = new xmlhttprequest(); addlisteners(xhr); xhr.open("get", url); xhr.send(); return xhr; } xhrbuttonsuccess.addeventlistener('click', () => { runxhr('https://mdn.mozillademos.org/files/16553/dgszyjnxcaipwzy.jpg'); }); xhrbuttonerror.addeventlistener('click', () => { runxhr('https://somewhere.org/i-dont-exist'); }); xhrbuttonabort.addeventlistener('click', () => { runxhr('https://mdn.mozillademos.org/files/16553/dgszyjnxcaipwzy.jpg').abort(); }); result specifications specification status comment xmlhttprequest living standard ...

XMLHttpRequest: load event - Web APIs
ut class="xhr abort" type="button" name="xhr" value="click to start xhr (abort)" /> </div> <textarea readonly class="event-log"></textarea> css .event-log { width: 25rem; height: 4rem; border: 1px solid black; margin: .5rem; padding: .2rem; } input { width: 11rem; margin: .5rem; } js const xhrbuttonsuccess = document.queryselector('.xhr.success'); const xhrbuttonerror = document.queryselector('.xhr.error'); const xhrbuttonabort = document.queryselector('.xhr.abort'); const log = document.queryselector('.event-log'); function handleevent(e) { log.textcontent = log.textcontent + `${e.type}: ${e.loaded} bytes transferred\n`; } function addlisteners(xhr) { xhr.addeventlistener('loadstart', handleevent); xhr.addeventlistener('load', handleevent); ...
...deventlistener('error', handleevent); xhr.addeventlistener('abort', handleevent); } function runxhr(url) { log.textcontent = ''; const xhr = new xmlhttprequest(); addlisteners(xhr); xhr.open("get", url); xhr.send(); return xhr; } xhrbuttonsuccess.addeventlistener('click', () => { runxhr('https://mdn.mozillademos.org/files/16553/dgszyjnxcaipwzy.jpg'); }); xhrbuttonerror.addeventlistener('click', () => { runxhr('https://somewhere.org/i-dont-exist'); }); xhrbuttonabort.addeventlistener('click', () => { runxhr('https://mdn.mozillademos.org/files/16553/dgszyjnxcaipwzy.jpg').abort(); }); result specifications specification status comment xmlhttprequest living standard ...

XMLHttpRequest: loadend event - Web APIs
ut class="xhr abort" type="button" name="xhr" value="click to start xhr (abort)" /> </div> <textarea readonly class="event-log"></textarea> css .event-log { width: 25rem; height: 4rem; border: 1px solid black; margin: .5rem; padding: .2rem; } input { width: 11rem; margin: .5rem; } js const xhrbuttonsuccess = document.queryselector('.xhr.success'); const xhrbuttonerror = document.queryselector('.xhr.error'); const xhrbuttonabort = document.queryselector('.xhr.abort'); const log = document.queryselector('.event-log'); function handleevent(e) { log.textcontent = log.textcontent + `${e.type}: ${e.loaded} bytes transferred\n`; } function addlisteners(xhr) { xhr.addeventlistener('loadstart', handleevent); xhr.addeventlistener('load', handleevent); ...
...deventlistener('error', handleevent); xhr.addeventlistener('abort', handleevent); } function runxhr(url) { log.textcontent = ''; const xhr = new xmlhttprequest(); addlisteners(xhr); xhr.open("get", url); xhr.send(); return xhr; } xhrbuttonsuccess.addeventlistener('click', () => { runxhr('https://mdn.mozillademos.org/files/16553/dgszyjnxcaipwzy.jpg'); }); xhrbuttonerror.addeventlistener('click', () => { runxhr('https://somewhere.org/i-dont-exist'); }); xhrbuttonabort.addeventlistener('click', () => { runxhr('https://mdn.mozillademos.org/files/16553/dgszyjnxcaipwzy.jpg').abort(); }); result specifications specification status comment xmlhttprequest living standard ...

XMLHttpRequest: loadstart event - Web APIs
ut class="xhr abort" type="button" name="xhr" value="click to start xhr (abort)" /> </div> <textarea readonly class="event-log"></textarea> css .event-log { width: 25rem; height: 4rem; border: 1px solid black; margin: .5rem; padding: .2rem; } input { width: 11rem; margin: .5rem; } js const xhrbuttonsuccess = document.queryselector('.xhr.success'); const xhrbuttonerror = document.queryselector('.xhr.error'); const xhrbuttonabort = document.queryselector('.xhr.abort'); const log = document.queryselector('.event-log'); function handleevent(e) { log.textcontent = log.textcontent + `${e.type}: ${e.loaded} bytes transferred\n`; } function addlisteners(xhr) { xhr.addeventlistener('loadstart', handleevent); xhr.addeventlistener('load', handleevent); ...
...deventlistener('error', handleevent); xhr.addeventlistener('abort', handleevent); } function runxhr(url) { log.textcontent = ''; const xhr = new xmlhttprequest(); addlisteners(xhr); xhr.open("get", url); xhr.send(); return xhr; } xhrbuttonsuccess.addeventlistener('click', () => { runxhr('https://mdn.mozillademos.org/files/16553/dgszyjnxcaipwzy.jpg'); }); xhrbuttonerror.addeventlistener('click', () => { runxhr('https://somewhere.org/i-dont-exist'); }); xhrbuttonabort.addeventlistener('click', () => { runxhr('https://mdn.mozillademos.org/files/16553/dgszyjnxcaipwzy.jpg').abort(); }); result specifications specification status comment xmlhttprequest living standard ...

XMLHttpRequest: progress event - Web APIs
ut class="xhr abort" type="button" name="xhr" value="click to start xhr (abort)" /> </div> <textarea readonly class="event-log"></textarea> css .event-log { width: 25rem; height: 4rem; border: 1px solid black; margin: .5rem; padding: .2rem; } input { width: 11rem; margin: .5rem; } js const xhrbuttonsuccess = document.queryselector('.xhr.success'); const xhrbuttonerror = document.queryselector('.xhr.error'); const xhrbuttonabort = document.queryselector('.xhr.abort'); const log = document.queryselector('.event-log'); function handleevent(e) { log.textcontent = log.textcontent + `${e.type}: ${e.loaded} bytes transferred\n`; } function addlisteners(xhr) { xhr.addeventlistener('loadstart', handleevent); xhr.addeventlistener('load', handleevent); ...
...deventlistener('error', handleevent); xhr.addeventlistener('abort', handleevent); } function runxhr(url) { log.textcontent = ''; const xhr = new xmlhttprequest(); addlisteners(xhr); xhr.open("get", url); xhr.send(); return xhr; } xhrbuttonsuccess.addeventlistener('click', () => { runxhr('https://mdn.mozillademos.org/files/16553/dgszyjnxcaipwzy.jpg'); }); xhrbuttonerror.addeventlistener('click', () => { runxhr('https://somewhere.org/i-dont-exist'); }); xhrbuttonabort.addeventlistener('click', () => { runxhr('https://mdn.mozillademos.org/files/16553/dgszyjnxcaipwzy.jpg').abort(); }); result specifications specification status comment xmlhttprequest living standard ...

XMLHttpRequest - Web APIs
rtobsolete since gecko 22 this gecko-only feature, a boolean, was removed in firefox/gecko 22.
... javascript code, use open() instead.

SVG Event Attributes - SVG: Scalable Vector Graphics
upports, svg supports that as an event attribute, following the same requirements as for html event attributes.
...in, onend, onrepeat document event attributes onabort, onerror, onresize, onscroll, onunload document element event attributes oncopy, oncut, onpaste global event attributes oncancel, oncanplay, oncanplaythrough, onchange, onclick, onclose, oncuechange, ondblclick, ondrag, ondragend, ondragenter, ondragexit, ondragleave, ondragover, ondragstart, ondrop, ondurationchange, onemptied, onended, onerror, onfocus, oninput, oninvalid, onkeydown, onkeypress, onkeyup, onload, onloadeddata, onloadedmetadata, onloadstart, onmousedown, onmouseenter, onmouseleave, onmousemove, onmouseout, onmouseover, onmouseup, onmousewheel, onpause, onplay, onplaying, onprogress, onratechange, onreset, onresize, onscroll, onseeked, onseeking, onselect, onshow, onstalled, onsubmit, onsuspend, ontimeupdate, ontoggle, on...

tabs - Archive of obsolete content
a: "blah" } }); } }); the values are accessible to content scripts via the self.options property: // content-script.js alert(self.options.a); onmessage function a function called when the content worker receives a message from content scripts.

content/worker - Archive of obsolete content
loaded before those specified by the contentscript option.

core/promise - Archive of obsolete content
s defer function, which is where all promises ultimately come from.

Canvas code snippets - Archive of obsolete content
(); remotecanvas.load(); convert image files to base64 strings the following code gets a remote image and converts its content to data uri scheme.

Rosetta - Archive of obsolete content
"" : odicts[smimetype](oscript.text); obaton.parentnode.insertbefore(ocompiled, obaton); } function reqerror (oerror) { throw new urierror("the script " + oerror.target.src + " is not accessible."); } function reqsuccess () { createscript(this.refscript, this); } function getsource (oscript) { var oreq = new xmlhttprequest(); oreq.onload = reqsuccess; oreq.onerror = reqerror; oreq.refscript = oscript; oreq.open("get", oscript.src, true); oreq.send(null); } function parsescript (oscript) { if (oscript.hasattribute("type") && !rignoremimes.test(oscript.getattribute("type").tolowercase())) { oscript.hasattribute("src") ?

Displaying web content in an extension without security issues - Archive of obsolete content
linkinbrowser(event.target.href); } safe html manipulation functions when it comes to displaying the data, it is tempting to generate some html code and to insert it into the document via innerhtml.

How to convert an overlay extension to restartless - Archive of obsolete content
ch it from an interface: const xmlhttprequest = components.constructor("@mozilla.org/xmlextras/xmlhttprequest;1", "nsixmlhttprequest"); here's how to load a file using it: function loadfile(url,type,returnresult) { var request = new xmlhttprequest(); request.open("get", url, true); // async=true request.responsetype = type; request.onerror = function(event) { logerrormessage("error attempting to load: " + url); returnresult(null); }; request.onload = function(event) { if (request.response) returnresult(request.response); else request.onerror(event); }; request.send(); } loadfile("chrome://myaddon/content/filename.ext",datatype,function(data) { /* do stuff w...

Migrate apps from Internet Explorer to Mozilla - Archive of obsolete content
ds and properties for mozilla's xmlhttprequest.

Attribute (XUL) - Archive of obsolete content
t minresultsforpopup minwidth mode modifiers mousethrough movetoclick multiline multiple name negate newlines next noautofocus noautohide noinitialfocus nomatch norestorefocus object observes onbeforeaccept onbookmarkgroup onchange onclick onclosetab oncommand oncommandupdate ondialogaccept ondialogcancel ondialogclosure ondialogextra1 ondialogextra2 ondialoghelp onerror onerrorcommand onextra1 onextra2 oninput onload onnewtab onpageadvanced onpagehide onpagerewound onpageshow onpaneload onpopuphidden onpopuphiding onpopupshowing onpopupshown onsearchcomplete onselect ontextcommand ontextentered ontextrevert ontextreverted onunload onwizardback onwizardcancel onwizardfinish onwizardnext open ordinal orient pack pageid pageincrement...

Browser Detection and Cross Browser Support - Archive of obsolete content
e that users of browsers which do not support the level of javascript used in your content to turn off javascript in order to be able to use your content.

RDF in Mozilla FAQ - Archive of obsolete content
allows you to spy on a datasource's progress.

Async scripts for asm.js - Game development
ild(script); both are counted as 'inline' scripts and get compiled and then run immediately.

Handling common JavaScript problems - Learn web development
function returns false, then we run the code inside the second part of the conditional — this runs a function called loadscript(), which loads the polyfills into the page, then runs main() after the loading has finished.

HTMLIFrameElement.executeScript()
of the browser api requires a privileged app, and browser and/or embed-apps permissions, depending on what you want to do.

HTMLIFrameElement.getMuted()
browser <iframe> is currently muted.

HTMLIFrameElement.getScreenshot()
ms (this delay is defined by the gecko dom.browserelement.maxscreenshotdelayms preference).

HTMLIFrameElement.getVolume()
volume of the browser <iframe>.

IPDL Tutorial
t!

Http.jsm
postdata this can be: a string: send it as is an array of parameters: encode as form values null/undefined: no post data.

OS.File for the main thread
|data| return promise.then(function onsuccess(bytes) { return loop(pos + bytes); // ...

Examples
thisimagepromise.promise); myimage.onload = function() { loadthisimagepromise.resolve('succesfully loaded image at path = "' + path + '" the width of this image is = "' + this.naturalwidth + '".'); if (!this.naturalwidth) { loadthisimagepromise.reject('image loaded but it has 0 width at path = "' + path + '" the naturalwidth was 0'); } } myimage.onerror = function(e) { loadthisimagepromise.reject('an error occured while loading path = "' + path + '".

Sqlite.jsm
); } catch (err) { // an error occurred.

WebRequest.jsm
name string header name, for example "content-type" value string header value, for example "image/png" chrome incompatibilities although this api is modeled on chrome's webrequest extension api, there are some differences.

JS::CompileOptions
lycompileoptions method description bool mutederrors() const determines if errors are muted.

JSErrorReport
column unsigned zero-based column index in line in the source that caused the error.

nsIAbstractWorker
dom/interfaces/threads/nsidomworkers.idlscriptable this interface is an abstract interface used to implement the web workers architecture.

nsIDOMOfflineResourceList
items nsidomofflineresourcelist the list of dynamically-managed entries in the offline resource list.

nsIWorkerGlobalScope
de' of a worker.

nsIXMLHttpRequestEventTarget
ent listeners used when uploading data using the xmlhttprequest object.

nsIXMLHttpRequestUpload
this interface provides access to the features needed when uploading data using nsixmlhttprequest.

XPCOM Interface Reference
xt2dnsidomchromewindownsidomclientrectnsidomdesktopnotificationnsidomdesktopnotificationcenternsidomelementnsidomeventnsidomeventgroupnsidomeventlistenernsidomeventtargetnsidomfilensidomfileerrornsidomfileexceptionnsidomfilelistnsidomfilereadernsidomfontfacensidomfontfacelistnsidomgeogeolocationnsidomgeopositionnsidomgeopositionaddressnsidomgeopositioncallbacknsidomgeopositioncoordsnsidomgeopositionerrornsidomgeopositionerrorcallbacknsidomgeopositionoptionsnsidomglobalpropertyinitializernsidomhtmlaudioelementnsidomhtmlformelementnsidomhtmlmediaelementnsidomhtmlsourceelementnsidomhtmltimerangesnsidomjswindownsidommousescrolleventnsidommoznetworkstatsnsidommoznetworkstatsdatansidommoznetworkstatsmanagernsidommoztoucheventnsidomnshtmldocumentnsidomnavigatordesktopnotificationnsidomnodensidomoffliner...

XPCOM Interface Reference by grouping
browser autocomplete nsiautocompletecontroller nsiautocompleteinput nsiautocompletesearch console nsiconsolelistener nsiconsolemessage nsiconsoleservice document nsidocshell dom device nsidomgeogeolocation nsidomgeoposition nsidomgeopositionaddress nsidomgeopositioncallback nsidomgeopositioncoords nsidomgeopositionerror nsidomgeopositionerrorcallback nsidomgeopositionoptions nsidomglobalpropertyinitializer element nsidomchromewindow nsidomclientrect nsidomelement nsidomhtmlaudioelement nsidomhtmlformelement nsidomhtmlmediaelement nsidomhtmlsourceelement nsidomhtmltimeranges nsidomjswindow nsidomnode nsidomnshtmldocument nsidomstorageitem nsi...

MailNews fakeserver
use is very small, most people shouldn't have to write an entirely new daemon and handler setup by themselves.

Debugger - Firefox Developer Tools
atement, or a new exception.

AbstractWorker - Web APIs
ctworker interface of the web workers api is an abstract interface that defines properties and methods that are common to all types of worker, including not only the basic worker, but also serviceworker and sharedworker.

Accelerometer.Accelerometer() - Web APIs
stent with the policies set on your server.

AddressErrors.organization - Web APIs
an object based on addresserrors includes an organization property when the address's organization property couldn't be validated.

AddressErrors.region - Web APIs
an object based on addresserrors includes a region property when the address's region property couldn't be validated.

AmbientLightSensor.illuminance - Web APIs
ng that would ever be shown to a user.

AmbientLightSensor - Web APIs
bientlightsensor() creates a new ambientlightsensor object.

CSS.registerProperty() - Web APIs
ing defined.

DOMError - Web APIs
or the string contains invalid characters.

Element: error event - Web APIs
the error event is fired on an element object when a resource failed to load, or can't be used.

Element.innerHTML - Web APIs
s case although this may look like a cross-site scripting attack, the result is harmless.

Element - Web APIs
iss the current open dialog.

EventSource - Web APIs
representing the state of the connection.

FileException - Web APIs
ter and adds several new error codes.

FileReader: error event - Web APIs
the error event is fired when the read failed due to an error (for example, because the file was not found or not readable).

FileSystemFileEntry.file() - Web APIs
le and calls a specified callback function with the received text (in a string object) once the read is completed.

FileSystemFileEntry - Web APIs
blob, appending text to it, and passing the blob to filewriter.write().

Geolocation.getCurrentPosition() - Web APIs
the geolocation.getcurrentposition() method is used to get the current position of the device.

Geolocation.watchPosition() - Web APIs
be called automatically each time the position of the device changes.

Using the Geolocation API - Web APIs
ur latitude and longitude } you can however get a number of other bits of information from a geolocationcoordinates object, including altitude, speed, what direction the device is facing, and an accuracy measure of the altitude, longitude, and latitude data.

HTMLCanvasElement - Web APIs
rol to an offscreencanvas object, either on the main thread or on a worker.

HTMLImageElement.complete - Web APIs
lete property before attempting to do its work.

HTMLImageElement - Web APIs
s properties from its parent, htmlelement.

HTMLMediaElement.error - Web APIs
xamining this object.

HTMLMediaElement: error event - Web APIs
the error event is fired when the resource could not be loaded due to an error (for example, a network connectivity problem).

Ajax navigation example - Web APIs
function filterurl (surl, sviewmode) { return surl.replace(rsearch, "") + ("?" + surl.replace(rhost, "&").replace(rview, sviewmode ?

IDBDatabase.close() - Web APIs
is connection once this method is called.

IDBDatabase: close event - Web APIs
database connection is unexpectedly closed.

IDBDatabase.createObjectStore() - Web APIs
tabase var request = window.indexeddb.open("todolist", 4); // this handler is called when a new version of the database // is created, either when one has not been created before // or when a new version number is submitted by calling // window.indexeddb.open().

IDBDatabase.name - Web APIs
database connection being opened, the resulting idbdatabase object being stored in a db variable, and the name property then being logged.

IDBDatabase.objectStoreNames - Web APIs
his feature is available in web workers.

IDBDatabase.transaction() - Web APIs
t with // all the to-do list data already in the idb displaydata(); }; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of opening the transaction transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed: database modification finished.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.

IDBDatabase.version - Web APIs
ed, this attribute is an empty string.

IDBFactory.deleteDatabase() - Web APIs
rsion 26, you can include a non-standard optional storage parameter that specifies whether you want to delete a permanent (the default value) indexeddb, or an indexeddb in temporary storage (aka shared pool.) return value a idbopendbrequest on which subsequent events related to this request are fired.

IDBFactory.open() - Web APIs
indow.msidbtransaction; window.idbkeyrange = window.idbkeyrange || window.webkitidbkeyrange || window.msidbkeyrange; // (mozilla has never prefixed these objects, so we don't // need window.mozidb*) // let us open version 4 of our database var dbopenrequest = window.indexeddb.open("todolist", 4); // these two event handlers act on the database being opened // successfully, or not dbopenrequest.onerror = function(event) { note.innerhtml += '<li>error loading database.</li>'; }; dbopenrequest.onsuccess = function(event) { note.innerhtml += '<li>database initialised.</li>'; // store the result of opening the database in the db // variable.

IDBFactory - Web APIs
on || window.msidbtransaction; window.idbkeyrange = window.idbkeyrange || window.webkitidbkeyrange || window.msidbkeyrange; // (mozilla has never prefixed these objects, so we don't need window.mozidb*) // let us open version 4 of our database var dbopenrequest = window.indexeddb.open("todolist", 4); // these two event handlers act on the database being opened successfully, or not dbopenrequest.onerror = function(event) { console.error("error loading database."); }; dbopenrequest.onsuccess = function(event) { console.info("database initialised."); // store the result of opening the database in the db variable.

IDBMutableFile - Web APIs
jects are bound to a fake file system built on top of indexeddb, such an object is created using the idbdatabase.createmutablefile method.

IDBObjectStore.add() - Web APIs
: 30, day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of the transaction completing, when everything is done transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.

IDBObjectStore.autoIncrement - Web APIs
: 30, day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of the transaction completing, when everything is done transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.

IDBObjectStore.clear() - Web APIs
form the object store cleardata(); }; function cleardata() { // open a read/write db transaction, ready for clearing the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of the transaction completing, when everything is done transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error: ' + transaction.error + '</li>'; }; // create an object store on the transaction var objectstore = transaction.objectstore("todolist"); // make a request to clear all the data out of the object store var objectstorerequest = objectstore.clear(); objectstorerequest.onsuccess = function(event) { /...

IDBObjectStore.delete() - Web APIs
rd from the database deletedata(); }; function deletedata() { // open a read/write db transaction, ready for deleting the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of the transaction completing, when everything is done transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error: ' + transaction.error + '</li>'; }; // create an object store on the transaction var objectstore = transaction.objectstore("todolist"); // make a request to delete the specified record out of the object store var objectstorerequest = objectstore.delete("walk dog"); objectstorerequest.onsuccess = fun...

IDBObjectStore.get() - Web APIs
e data from the database getdata(); }; function getdata() { // open a read/write db transaction, ready for retrieving the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of the transaction completing, when everything is done transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error: ' + transaction.error + '</li>'; }; // create an object store on the transaction var objectstore = transaction.objectstore("todolist"); // make a request to get a record by key from the object store var objectstorerequest = objectstore.get("walk dog"); objectstorerequest.onsuccess = function(event) ...

IDBObjectStore.indexNames - Web APIs
30, day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of the transaction completing, when everything is done transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.

IDBObjectStore.keyPath - Web APIs
: 30, day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of the transaction completing, when everything is done transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.

IDBObjectStore.name - Web APIs
: 30, day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of the transaction completing, when everything is done transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.

IDBObjectStore.transaction - Web APIs
: 30, day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of the transaction completing, when everything is done transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.

IDBTransaction.abort() - Web APIs
day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of opening the transaction transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed: database modification finished.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.

IDBTransaction.commit() - Web APIs
invalidstateerror the transaction state is not active.

IDBTransaction.db - Web APIs
, day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of opening the transaction transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed: database modification finished.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.

IDBTransaction.mode - Web APIs
, day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of opening the transaction transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed: database modification finished.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.

IDBTransaction.objectStore() - Web APIs
, day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of opening the transaction transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed: database modification finished.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.

IDBTransaction.onabort - Web APIs
, day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of opening the transaction transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed: database modification finished.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error: ' + transaction.error + '</li>'; }; // create an object store on the transaction var objectstore = transaction.objectstore("todolist"); // add our newitem object to the object store var objectstorerequest = objectstore.add(newitem[0]); objectstorerequest.onsuccess = function(event) { // report t...

IDBTransaction.oncomplete - Web APIs
, day: 24, month: "december", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of opening the transaction transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction completed: database modification finished.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error: ' + transaction.error + '</li>'; }; // create an object store on the transaction var objectstore = transaction.objectstore("todolist"); // add our newitem object to the object store var objectstorerequest = objectstore.add(newitem[0]); objectstorerequest.onsuccess = function(event) { // report t...

IDBVersionChangeEvent.newVersion - Web APIs
ebkitidbtransaction || window.msidbtransaction; window.idbkeyrange = window.idbkeyrange || window.webkitidbkeyrange || window.msidbkeyrange; // (mozilla has never prefixed these objects, // so we don't need window.mozidb*) // let us open version 4 of our database var dbopenrequest = window.indexeddb.open("todolist", 4); // these two event handlers act on the database being opened dbopenrequest.onerror = function(event) { note.innerhtml += '<li>error loading database.</li>'; }; dbopenrequest.onsuccess = function(event) { note.innerhtml += '<li>database initialised.</li>'; // store the result of opening the database in the db variable.

IDBVersionChangeEvent - Web APIs
on || window.msidbtransaction; window.idbkeyrange = window.idbkeyrange || window.webkitidbkeyrange || window.msidbkeyrange; // (mozilla has never prefixed these objects, so we don't need window.mozidb*) // let us open version 4 of our database var dbopenrequest = window.indexeddb.open("todolist", 4); // these two event handlers act on the database being opened successfully, or not dbopenrequest.onerror = function(event) { note.innerhtml += '<li>error loading database.</li>'; }; dbopenrequest.onsuccess = function(event) { note.innerhtml += '<li>database initialised.</li>'; // store the result of opening the database in the db variable.

Basic concepts - Web APIs
ishes, and the type of event you get lets you know if the operation succeeded or failed.

Checking when a deadline is due - Web APIs
year : year.value, notified : "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["todolist"], "readwrite"); // report on the success of opening the transaction transaction.oncomplete = function(event) { note.innerhtml += '<li>transaction opened for task addition.</li>'; }; transaction.onerror = function(event) { note.innerhtml += '<li>transaction not opened due to error.

LockedFile - Web APIs
.active read only a flag indicating if the file can be accessed (true) or not (false).

MediaError.code - Web APIs
_supported 4 the associated resource or media provider object (such as a mediastream) has been found to be unsuitable.

MediaError.message - Web APIs
arts of the code are displayed; you can see the complete source code here.

MediaRecorderErrorEvent() - Web APIs
the mediarecordererrorevent() constructor creates a new mediarecordererrorevent object that represents an error that occurred during the recording of media by the mediastream recording api.

MediaSource.endOfStream() - Web APIs
when the end of the stream is reached.

MediaStream Recording API - Web APIs
he source media stops playing.

NDEFReader - Web APIs
ndefreader.ndefreader() returns an ndefreader with configuration specified in the parameters or default ones if no parameters are specified.

Notification - Web APIs
t parameter of the constructor.

Using the Notifications API - Web APIs
fication instance: click triggered when the user clicks on the notification.

PaintWorklet.registerPaint - Web APIs
intworklet interface registers a class programmatically generate an image where a css property expects a file.

PaymentResponse.retry() - Web APIs
the paymentresponse interface's retry() method makes it possible to ask the user to retry a payment after an error occurs during processing.

Payment Request API - Web APIs
bject providing redacted address information that is provided as the methoddetails on the paymentmethodchange event sent to the paymentrequest when the user changes payment information.

PushManager.register() - Web APIs
cess or failure of the method call.

PushManager.unregister() - Web APIs
istration those objects are anonymous javascript objects with the following properties: pushendpoint a string representing the url of the unregistered endpoint.

RTCIceCandidate.address - Web APIs
address in the options object, but the address is automatically extracted from the candidate a-line, if it's formatted properly.

RTCIceCandidate.foundation - Web APIs
n be used to correlate candidates that are present on multiple rtcicetransport objects syntax var foundation = rtcicecandidate.foundation; value a domstring which uniquely identifies the candidate across all rtcicetransports on which it is available.

RTCIceCandidate.port - Web APIs
x var port = rtcicecandidate.port; value a 16-bit number indicating the port number on the device at the address indicated by ip at which the candidate's peer can be reached.

RTCIceCandidate.priority - Web APIs
alue indicating the priority of the candidate according to the remote peer.

RTCIceCandidate.protocol - Web APIs
itional information about the kind of tcp candidate represented by the object.

RTCIceCandidate.type - Web APIs
y the stun server to represent the candidate's peer anonymously.

RTCIdentityErrorEvent.idp - Web APIs
ovider (idp) generating the error response event.

RTCIdentityErrorEvent.loginUrl - Web APIs
ty provider (idp).

RTCIdentityErrorEvent.protocol - Web APIs
a domstring describing the idp protocol in use.

RTCPeerConnection.addIceCandidate() - Web APIs
o 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.createDataChannel() - Web APIs
5 bytes (bytes, rather than characters).

RTCPeerConnection.getIdentityAssertion() - Web APIs
the rtcpeerconnection.getidentityassertion() method initiates the gathering of an identity assertion.

RTCPeerConnection.setConfiguration() - Web APIs
changes are not additive; instead, the new values completely replace the existing ones.

RTCRtpSender.replaceTrack() - Web APIs
is not allowed (see things that require negotiation).

SVGElement: error event - Web APIs
the error event is fired when an svg element does not load properly or when an error occurs during script execution.

SVGElement - Web APIs
assigning an event listener to the equivalent on...

Sensor - Web APIs
ambientlightsensor gyroscope linearaccelerationsensor magnetometer orientationsensor properties sensor.activated read only returns a boolean indicating whether the sensor is active.

ServiceWorkerContainer - Web APIs
r.

Using Service Workers - Web APIs
ad = (url) => { return new promise((resolve, reject) => { var request = new xmlhttprequest(); request.open('get', url); request.responsetype = 'blob'; request.onload = () => { if (request.status == 200) { resolve(request.response); } else { reject(error('image didn\'t load successfully; error code:' + request.statustext)); } }; request.onerror = () => { reject(error('there was a network error.')); }; request.send(); }); } we return a new promise using the promise() constructor, which takes as an argument a callback function with resolve and reject parameters.

SharedWorker.port - Web APIs
er through a messageport object accessed using the sharedworker.port property — the port is started using its start() method: var myworker = new sharedworker('worker.js'); myworker.port.start(); for a full example, see our basic shared worker example (run shared worker.) specifications specification status comment html living standardthe definition of 'abstractworker.onerror' in that specification.

SharedWorker - Web APIs
ote: if sharedworker can be accessed from several browsing contexts, all those browsing contexts must share the exact same origin (same protocol, host and port).

SourceBuffer - Web APIs
m(), or sourcebuffer.remove() operation is currently in progress.

SpeechRecognition - Web APIs
fired when the user agent has started to capture audio.

SpeechSynthesisErrorEvent.error - Web APIs
etvoices(); ...

SpeechSynthesisErrorEvent - Web APIs
etvoices(); ...

SpeechSynthesisUtterance - Web APIs
listener to the oneventname property of this interface.

SubtleCrypto.decrypt() - Web APIs
o known as ciphertext).

SubtleCrypto.encrypt() - Web APIs
s the plaintext).

WebGL: 2D and 3D graphics for the web - Web APIs
webgl_compressed_texture_astc webgl_compressed_texture_atc webgl_compressed_texture_etc webgl_compressed_texture_etc1 webgl_compressed_texture_pvrtc webgl_compressed_texture_s3tc webgl_compressed_texture_s3tc_srgb webgl_debug_renderer_info webgl_debug_shaders webgl_depth_texture webgl_draw_buffers webgl_lose_context events webglcontextlost webglcontextrestored webglcontextcreationerror constants and types webgl constants webgl types webgl 2 webgl 2 is a major update to webgl which is provided through the webgl2renderingcontext interface.

A simple RTCDataChannel sample - Web APIs
eateoffer() .then(offer => localconnection.setlocaldescription(offer)) .then(() => remoteconnection.setremotedescription(localconnection.localdescription)) .then(() => remoteconnection.createanswer()) .then(answer => remoteconnection.setlocaldescription(answer)) .then(() => localconnection.setremotedescription(remoteconnection.localdescription)) .catch(handlecreatedescriptionerror); let's go through this line by line and decipher what it means.

WebSocket: error event - Web APIs
the error event is fired when a connection with a websocket has been closed due to an error (some data couldn't be sent for example).

Writing WebSocket client applications - Web APIs
destination doesn't allow access.

Writing a WebSocket server in C# - Web APIs
socket(wsuri); button.addeventlistener("click", onclickbutton); websocket.onopen = function (e) { writetoscreen("connected"); dosend("websocket rocks"); }; websocket.onclose = function (e) { writetoscreen("disconnected"); }; websocket.onmessage = function (e) { writetoscreen("<span>response: " + e.data + "</span>"); }; websocket.onerror = function (e) { writetoscreen("<span class=error>error:</span> " + e.data); }; function dosend(message) { writetoscreen("sent: " + message); websocket.send(message); } function writetoscreen(message) { output.insertadjacenthtml("afterbegin", "<p>" + message + "</p>"); } function onclickbutton() { var text = textarea.value; ...

Web Speech API - Web APIs
e details on using these features, see using the web speech api.

Window: error event - Web APIs
the error event is fired on a window object when a resource failed to load or couldn't be used — for example if a script has an execution error.

Worker - Web APIs
ions.) in firefox extensions, if you want to use workers with access to js-ctypes, use chromeworker object instead.

WorkerGlobalScope - Web APIs
indoworworkerglobalscope.issecurecontext read only returns a boolean indicating whether the current context is secure (true) or not (false).

HTML in XMLHttpRequest - Web APIs
{ if (!window.xmlhttprequest) { window.settimeout(function() { callback(false); }, 0); return; } var done = false; var xhr = new window.xmlhttprequest(); xhr.onreadystatechange = function() { if (this.readystate == 4 && !done) { done = true; callback(!!(this.responsexml && this.responsexml.title && this.responsexml.title == "&&<")); } } xhr.onabort = xhr.onerror = function() { if (!done) { done = true; callback(false); } } try { xhr.open("get", "detect.html"); xhr.responsetype = "document"; xhr.send(); } catch (e) { window.settimeout(function() { if (!done) { done = true; callback(false); } }, 0); } } the argument callback is a function that will be called asynchronously with t...

How to check the security state of an XMLHTTPRequest over SSL - Web APIs
ateerror'; break; case 4: // ssl_error_bad_certificate, ssl(4) errname = 'securitybadcertificateerror'; break; case 8: // ssl_error_unsupported_certificate_type, ssl(8) errname = 'securityunsupportedcertificatetypeerror'; break; case 9: // ssl_error_unsupported_version, ssl(9) errname = 'securityunsupportedtlsversionerror'; break; case 12: // ssl_error_bad_cert_domain, ssl(12) errname = 'securitycertificatedomainmismatcherror'; break; default: errname = 'securityerror'; break; } } } else { errtype = 'network'; switch (status) { // connect to host:port failed case 0x804b000c: // ns_error_connection_refused, network(13)...

XMLHttpRequest.upload - Web APIs
its process.

XMLHttpRequestEventTarget - Web APIs
mily="consolas,monaco,andale mono,monospace" fill="#4d4e53" text-anchor="middle" alignment-baseline="middle">xmlhttprequesteventtarget</text></a></svg></div> a:hover text { fill: #0095dd; pointer-events: all;} properties xmlhttprequesteventtarget.onabort contains the function to call when a request is aborted and the abort event is received by this object.

XRWebGLLayer() - Web APIs
configuration.

Parsing and serializing XML - Developer guides
essage console.log(odom.documentelement.nodename == "parsererror" ?

<body>: The Document Body element - HTML: Hypertext Markup Language
ks.

<img>: The Image Embed element - HTML: Hypertext Markup Language
image/webp .webp chrome, edge, firefox, opera the abbreviation for each format links to a longer description of the format, its capabilities, and detailed browser compatibility information; including which versions introduced support and specific special features that may have been introduced later.

<link>: The External Resource Link element - HTML: Hypertext Markup Language
events you can determine when a style sheet has been loaded by watching for a load event to fire on it; similarly, you can detect if an error has occurred while processing a style sheet by watching for an error event: <script> var mystylesheet = document.queryselector('#my-stylesheet'); mystylesheet.onload = function() { // do something interesting; the sheet has been loaded } mystylesheet.onerror = function() { console.log("an error occurred loading the stylesheet!"); } </script> <link rel="stylesheet" href="mystylesheet.css" id="my-stylesheet"> note: the load event fires once the stylesheet and all of its imported content has been loaded and parsed, and immediately before the styles start being applied to the content.

<script>: The Script element - HTML: Hypertext Markup Language
ntinuing to parse.

Global attributes - HTML: Hypertext Markup Language
ty purposes.

Feature-Policy: geolocation - HTTP
the http feature-policy header geolocation directive controls whether the current document is allowed to use the geolocation interface.

Feature-Policy - HTTP
rols whether the current document is allowed to use element.requestfullscreen().

Index - HTTP
ypeerror.

HTTP Index - HTTP
peerror.

Promise() constructor - JavaScript
ve(somevalue) // fulfilled // or // reject("failure reason") // rejected }); making functions return a promise to provide a function with promise functionality, have it return a promise: function myasyncfunction(url) { return new promise((resolve, reject) => { const xhr = new xmlhttprequest() xhr.open("get", url) xhr.onload = () => resolve(xhr.responsetext) xhr.onerror = () => reject(xhr.statustext) xhr.send() }); } specifications specification ecmascript (ecma-262)the definition of 'promise constructor' in that specification.

requiredFeatures - SVG: Scalable Vector Graphics
p://www.w3.org/tr/svg11/feature#basicfilter the browser supports the <filter>, <feblend>, <fecolormatrix>, <fecomponenttransfer>, <fecomposite>, <feflood>, <fegaussianblur>, <feimage>, <femerge>, <femergenode>, <feoffset>, <fetile>, <fefuncr>, <fefuncg>, <fefuncb> and <fefunca> elements http://www.w3.org/tr/svg11/feature#documenteventsattribute the browser supports the onunload, onabort, onerror, onresize, onscroll and onzoom attributes http://www.w3.org/tr/svg11/feature#graphicaleventsattribute the browser supports the onfocusin, onfocusout, onactivate, onclick, onmousedown, onmouseup, onmouseover, onmousemove, onmouseout and onload attributes http://www.w3.org/tr/svg11/feature#animationeventsattribute the browser supports the onbegin, onend, onrepeat and onload attributes ...

SVG Attribute reference - SVG: Scalable Vector Graphics
butetype, attributename animation timing attributes begin, dur, end, min, max, restart, repeatcount, repeatdur, fill animation value attributes calcmode, values, keytimes, keysplines, from, to, by, autoreverse, accelerate, decelerate animation addition attributes additive, accumulate event attributes animation event attributes onbegin, onend, onrepeat document event attributes onabort, onerror, onresize, onscroll, onunload global event attributes oncancel, oncanplay, oncanplaythrough, onchange, onclick, onclose, oncuechange, ondblclick, ondrag, ondragend, ondragenter, ondragexit, ondragleave, ondragover, ondragstart, ondrop, ondurationchange, onemptied, onended, onerror, onfocus, oninput, oninvalid, onkeydown, onkeypress, onkeyup, onload, onloadeddata, onloadedmetadata, onloadstart, ...