RTCPeerConnection: addstream event

{{APIRef("WebRTC")}}{{Deprecated_Header}}{{Non-standard_Header}}

The obsolete addstream event is sent to an {{domxref("RTCPeerConnection")}} when new media, in the form of a {{domxref("MediaStream")}} object, has been added to it.

[!WARNING] This event has been removed from the WebRTC specification. You should instead watch for the {{domxref("RTCPeerConnection.track_event", "track")}} event, which is sent for each media track added to the RTCPeerConnection.

You can, similarly, watch for streams to be removed from the connection by monitoring the {{domxref("RTCPeerConnection.removestream_event", "removestream")}} event.

This event is not cancelable and does not bubble.

Syntax

Use the event name in methods like {{domxref("EventTarget.addEventListener", "addEventListener()")}}, or set an event handler property.

addEventListener("addstream", (event) => { })

onaddstream = (event) => { }

Event type

A {{domxref("MediaStreamEvent")}}. Inherits from {{domxref("Event")}}.

{{InheritanceDiagram("MediaStreamEvent")}}

Event properties

A {{domxref("MediaStreamEvent")}} being an {{domxref("Event")}}, this event also implements these properties.

• {{domxref("MediaStreamEvent.stream")}} {{ReadOnlyInline}}
  • : Contains the {{domxref("MediaStream")}} containing the stream associated with the event.

Examples

This example looks to determine if the user's browser supports the {{domxref("RTCPeerConnection.track_event", "track")}} event. If it does, a track event listener is set up; otherwise, an addstream event listener is set up. pc is an RTCPeerConnection.

if (pc.addTrack !== undefined) {
  pc.ontrack = (ev) => {
    ev.streams.forEach((stream) => doAddStream(stream));
  };
} else {
  pc.onaddstream = (ev) => {
    doAddStream(ev.stream);
  };
}

This calls a function doAddStream() once for each stream being added to the {{domxref("RTCPeerConnection")}}, regardless of whether the browser sends addstream or track.

You can also use the {{domxref("EventTarget.addEventListener", "addEventListener()")}} method to set an event listener:

pc.addEventListener("addstream", (ev) => doAddStream(ev.stream), false);

Browser compatibility

{{Compat}}

See also

• WebRTC API
• {{domxref("RTCPeerConnection.addStream()")}}
• {{domxref("MediaStreamEvent")}}