TextTrackList.onremovetrack - Web APIs 编辑

The TextTrackList onremovetrack event handler is called when the removetrack event occurs, indicating that a text track has been removed from the media element, and therefore also from the TextTrackList.

The event is passed into the event handler in the form of a TrackEvent object, whose track property identifies the track that was removed from the media element's TextTrackList.

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

Syntax

TextTrackList.onremovetrack = eventHandler;

Value

Set onremovetrack to a function that accepts as input a TrackEvent object which indicates in its track property which text track has been removed from the media element.

Example

This simple example just fetches the current number of text tracks in the first media element whenever a track is removed from the media element.

document.querySelectorAll("video, audio")[0].textTracks.onremovetrack = function(event) {
  myTrackCount = document.querySelectorAll("video, audio")[0].textTracks.length;
};

The current number of text tracks remaining in the media element is obtained from TextTrackList property length.

Specifications