TextTrackList: addtrack event - Web APIs | MDN (original) (raw)
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The addtrack event is fired when a track is added to a TextTrackList.
Syntax
Use the event name in methods like addEventListener(), or set an event handler property.
js
addEventListener("addtrack", (event) => { })
onaddtrack = (event) => { }
Event type
A TrackEvent. Inherits from Event.
Event properties
In addition to the properties listed below, properties from the parent interface, Event, are available.
track Read only
The TextTrack object to which the event refers.
Examples
Using addEventListener():
js
const mediaElement = document.querySelector("video, audio");
mediaElement.textTracks.addEventListener("addtrack", (event) => {
console.log(`Text track: ${event.track.label} added`);
});
Using the onaddtrack event handler property:
js
const mediaElement = document.querySelector("video, audio");
mediaElement.textTracks.onaddtrack = (event) => {
console.log(`Text track: ${event.track.label} added`);
};
Specifications
| Specification |
|---|
| HTML # event-media-addtrack |
| HTML # handler-tracklist-onaddtrack |
Browser compatibility
See also
- Related events: removetrack, change
- This event on VideoTrackList targets: addtrack
- This event on AudioTrackList targets: addtrack
- This event on MediaStream targets: addtrack
- Media Capture and Streams API
- WebRTC