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RTCIceTransport: gatheringstatechange event

A gatheringstatechange event is sent to an RTCIceTransport when its ICE candidate gathering state changes.

The gathering state, whose actual status can be found in the transport object's gatheringState property, indicates whether or not the ICE agent has begun gathering candidates, and if so, if it has finished doing so.

The key difference between gatheringstatechange and icegatheringstatechange is that the latter represents the overall state of the connection including every RTCIceTransport used by every RTCRtpSender and every RTCRtpReceiver on the entire connection. In contrast, gatheringstatechange represents changes to the candidate gathering state for a single transport.

This event is not cancelable and does not bubble.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

js

addEventListener("gatheringstatechange", (event) => {});

ongatheringstatechange = (event) => {};

Event type

A generic Event.

Examples

This example creates a handler for gatheringstatechange events on each RTCRtpSender associated with a given RTCPeerConnection. Here, the addEventListener() method is called to add a listener for gatheringstatechange events:

js

pc.getSenders().forEach((sender) => {
  sender.transport.iceTransport.addEventListener(
    "gatheringstatechange",
    (ev) => {
      let transport = ev.target;

      if (transport.gatheringState === "complete") {
        /* this transport has finished gathering candidates,
        but others may still be working on it */
      }
    },
    false,
  );
});

Likewise, you can use the ongatheringstatechange event handler property:

js

pc.getSenders().forEach((sender) => {
  sender.transport.iceTransport.ongatheringstatechange = (ev) => {
    let transport = ev.target;

    if (transport.gatheringState === "complete") {
      /* this transport has finished gathering candidates,
         but others may still be working on it */
    }
  };
});

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
gatheringstatechange_event 75 79 No No 62 15.4 75 75 No 54 15.4 11.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/RTCIceTransport/gatheringstatechange_event