The read-only
textTracks
property on
HTMLMediaElement
objects returns a
TextTrackList
object listing all of the
TextTrack
objects representing the media element's text tracks, in the same order as in
the list of text tracks.
You can detect when tracks are added to and removed from an
<audio>
or
<video>
element
using the
addtrack
and
removetrack
events. However, these
events aren't sent directly to the media element itself. Instead, they're sent to the
track list object of the
HTMLMediaElement
that corresponds to the type of track that was added to the element
The returned list is
live
; that is, as tracks are added to and removed from
the media element, the list's contents change dynamically. Once you have a reference to
the list, you can monitor it for changes to detect when new text tracks are added or
existing ones removed.
See
TextTrackList events
to learn
more about watching for changes to a media element's track list.