RTCPeerConnection.onicecandidate

The RTCPeerConnection.onicecandidate property is an EventHandler which specifies a function to be called when the icecandidate event occurs on an RTCPeerConnection instance. This happens whenever the local ICE agent needs to deliver a message to the other peer through the signaling server. This lets the ICE agent perform negotiation with the remote peer without the browser itself needing to know any specifics about the technology being used for signaling; simply implement this method to use whatever messaging technology you choose to send the ICE candidate to the remote peer.

Syntax

RTCPeerConnection.onicecandidate = eventHandler;

Value

This should be set to a function which you provide that accepts as input an RTCPeerConnectionIceEvent object representing the icecandidate event. The function should deliver the ICE candidate, whose SDP can be found in the event's candidate property, to the remote peer through the signaling server.

If the event's candidate property is null, ICE gathering has finished.

Example

The example below, which is based on the code from the article Signaling and video calling, sets up a handler for icecandidate events to send the candidates to the remote peer.

Example and sequence of icecandidate events happening:

13:28:58.561 ice RTCPeerConnectionIceEvent {isTrusted: true, candidate: RTCIceCandidate, type: "icecandidate", …}
13:28:58.562 ice RTCPeerConnectionIceEvent {isTrusted: true, candidate: RTCIceCandidate, type: "icecandidate", …}
13:28:58.660 ice RTCPeerConnectionIceEvent {isTrusted: true, candidate: RTCIceCandidate, type: "icecandidate", …}
13:28:58.661 ice RTCPeerConnectionIceEvent {isTrusted: true, candidate: RTCIceCandidate, type: "icecandidate", …}
13:28:58.661 ice RTCPeerConnectionIceEvent {isTrusted: true, candidate: null, type: "icecandidate", …}

pc.onicecandidate = function(event) {
  if (event.candidate) {
    // Send the candidate to the remote peer
  } else {
    // All ICE candidates have been sent
  }
}

Specifications

Browser compatibility

See also

• The icecandidate event and its type, RTCPeerConnectionIceEvent.