RTCIceTransport: selectedcandidatepairchange event

A selectedcandidatepairchange event is sent to an RTCIceTransport when the ICE agent selects a new pair of candidates that describe the endpoints of a viable connection. The pair of candidates is in turn described by an RTCIceCandidatePair object which contains one RTCIceCandidate representing the local end of the connection, and another representing the remote end of the connection.

Together, the candidates can be used to establish a connection to be used by the RTCIceTransport, and, by extension, by an RTCPeerConnection.

Examples

This example creates an event handler for selectedcandidatepairchange that updates a display providing the user information about the progress of the ICE negotiation for an RTCPeerConnection called pc.

let iceTransport = pc.getSenders[0].transport.iceTransport;
let localProtoElem = document.getElementById("local-protocol");
let remoteProtoElem = document.getElementById("remote-protocol");

iceTransport.addEventListener("selectedcandidatepairchange", ev => {
  let pair = iceTransport.getSelectedCandidatePair();
  localProtoElem.innerText = pair.local.protocol.toUpperCase();
  remoteProtoElem.innerText = pair.remote.protocol.toUpperCase();
}, false)

This can also be done by setting the onselectedcandidatepairchange event handler property directly.

let iceTransport = pc.getSenders[0].transport.iceTransport;
let localProtoElem = document.getElementById("local-protocol");
let remoteProtoElem = document.getElementById("remote-protocol");

iceTransport.onselectedcandidatepairchange = ev => {
  let pair = iceTransport.getSelectedCandidatePair();
  localProtoElem.innerText = pair.local.protocol.toUpperCase();
  remoteProtoElem.innerText = pair.remote.protocol.toUpperCase();
}

Specifications

Browser compatibility

See also

• WebRTC API
• WebRTC connectivity
• RTCIceTransport.onselectedcandidatepairchange

Related RTCIceTransport events

• statechange
• gatheringstatechange

Related RTCPeerConnection events

• negotiationneeded
• signalingstatechange
• iceconnectionstatechange
• icegatheringstatechange
• connectionstatechange