Web/API/AudioTrackList/onchange

The AudioTrackList property onchange is an event handler which is called when the change event occurs, indicating that one or more of the AudioTracks in the AudioTrackList have been enabled or disabled.

The event is passed into the event handler in the form of an Event object; the event doesn't provide any additional information. To determine the new state of media's tracks, you'll have to look at their AudioTrack.enabled flags.

Note: You can also add a handler for the change event using addEventListener().

Syntax

AudioTrackList.onchange = eventHandler;

Value

Set onchange to a function that should be called whenever tracks are enabled or disabled on the media element.

Example

This snippet establishes a handler for the change event that looks at each of the tracks in the list, calling a function to update the state of a user interface control that indicates the current state of the track.

var trackList = document.querySelector("video").audioTracks;

trackList.onchange = function(event) {
  trackList.forEach(function(track) {
    updateTrackEnabledButton(track.id, track.enabled);
  });
};

The updateTrackEnabledButton(), in this example, should be a function that finds a user interface control using the track's id (perhaps the app uses the track ID as the control element's ID) and the track's enabled flag to determine which state the control should be in now.

Specifications

Specification	Status	Comment
HTML Living StandardThe definition of 'AudioTrackList.onchange' in that specification.	Living Standard
HTML5The definition of 'AudioTrackList.onchange' in that specification.	Recommendation

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`onchange`	Chrome Full support 37 Disabled' Full support 37 Disabled' Disabled' From version 37: this feature is behind the `enable-experimental-web-platform-features` preference (needs to be set to `enabled`). To change preferences in Chrome, visit chrome://flags.	Edge Full support 79 Disabled' Full support 79 Disabled' Disabled' From version 79: this feature is behind the `enable-experimental-web-platform-features` preference (needs to be set to `enabled`). No support 12 — 79	Firefox Full support 33 Disabled' Full support 33 Disabled' Disabled' From version 33: this feature is behind the `media.track.enabled` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	IE Full support 10	Opera Full support 24 Disabled' Full support 24 Disabled' Disabled' From version 24: this feature is behind the `enable-experimental-web-platform-features` preference (needs to be set to `enabled`).	Safari Full support 6.1	WebView Android No support No	Chrome Android Full support 37 Disabled' Full support 37 Disabled' Disabled' From version 37: this feature is behind the `enable-experimental-web-platform-features` preference (needs to be set to `enabled`). To change preferences in Chrome, visit chrome://flags.	Firefox Android Full support 33 Disabled' Full support 33 Disabled' Disabled' From version 33: this feature is behind the `media.track.enabled` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	Opera Android Full support 24 Disabled' Full support 24 Disabled' Disabled' From version 24: this feature is behind the `enable-experimental-web-platform-features` preference (needs to be set to `enabled`).	Safari iOS Full support 7	Samsung Internet Android No support No

Legend

Full support: Full support
No support: No support
User must explicitly enable this feature.': User must explicitly enable this feature.

AudioTrackList.onchange by Mozilla Contributors is licensed under CC-BY-SA 2.5.