The TextTrack
interface—part of the API for handling WebVTT (text tracks on media presentations)—describes and controls the text track associated with a particular <track>
element.
Properties
This interface also inherits properties from EventTarget
.
TextTrack.activeCues
Read only- A
TextTrackCueList
object listing the currently active set of text track cues. Track cues are active if the current playback position of the media is between the cues' start and end times. TextTrack.cues
Read only- A
TextTrackCueList
which contains all of the track's cues. TextTrack.id
Read only- A
DOMString
which identifies the track, if it has one. If it doesn't have an ID, then this value is an empty string (""
). If theTextTrack
is associated with a<track>
element, then the track's ID matches the element's ID. TextTrack.inBandMetadataTrackDispatchType
Read only- Returns a
DOMString
which indicates the track's in-band metadata track dispatch type. needs details TextTrack.kind
Read only- Returns a
DOMString
indicating what kind of text track theTextTrack
describes. The value must be one of those in the TextTrackKind enum. TextTrack.label
Read only- A human-readable
DOMString
which contains the text track's label, if one is present; otherwise, this is an empty string (""
), in which case a custom label may need to be generated by your code using other attributes of the track, if the track's label needs to be exposed to the user. TextTrack.language
Read only- A
DOMString
which specifies the text language in which the text track's contents is written. The value must adhere to the format specified in the Tags for Identifying Languages (BCP 47) document from the IETF, just like the HTMLlang
attribute. For example, this can be"en-US"
for United States English or"pt-BR"
for Brazilian Portuguese. TextTrack.mode
- A
DOMString
specifying the track's current mode. Changing this property's value changes the track's current mode to match. Permitted values are listed under Text track mode constants below.
Event handlers
TextTrack.oncuechange
- A
EventHandler
specifying a function to be called when acuechange
event occurs. Handling these events lets you know when cues are entered and exited. A given text cue appears when the cue is entered and disappears when the cue is exited.
Methods
This interface also inherits methods from EventTarget
.
TextTrack.addCue()
- Adds a cue (specified as a
TextTrackCue
object to the track's list of cues. TextTrack.removeCue()
- Removes a cue (specified as a
TextTrackCue
object from the track's list of cues.
Example
tbd
Specifications
Specification | Status | Comment |
---|---|---|
WebVTT: The Web Video Text Tracks Format | Draft |
Browser compatibility
Feature | Chrome | Edge | Firefox (Gecko)[1] | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|---|
Basic support | 18 | 12 | 31 | 10 | 15 | 6 |
cuechange and oncuechange |
? | ? | 47 | ? | ? | ? |
Feature | Android | Chrome | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|
Basic support | 4.4 | 18 | 31 | ? | No support | No support | 7.1 |
cuechange and oncuechange |
? | ? | 47 | ? | No support | No support | ? |
[1] Firefox versions before FIrefox 50 didn't display captions when playing media without one or more video tracks being played.