RTCDataChannel: message event

The WebRTC message event is sent to the onmessage event handler on an RTCDataChannel object when a message has been received from the remote peer.

Examples

For a given RTCDataChannel, dc, created for a peer connection using its createDataChannel() method, this code sets up a handler for incoming messages and acts on them by adding the data contained within the message to the current document as a new <p> (paragraph) element.

dc.addEventListener("message", ev => {
  let newParagraph = document.createElement("p");
  let textNode = document.createTextNode(event.data);
  newParagraph.appendChild(textNode);

  document.body.appendChild(newParagraph);
}, false);

Lines 2-4 create the new paragraph element and add the message data to it as a new text node. Line 6 appends the new paragraph to the end of the document's body.

You can also use an RTCDataChannel object's onmessage event handler property to set the event handler:

dc.onmessage = ev => {
  let newParagraph = document.createElement("p");
  let textNode = document.createTextNode(event.data);
  newParagraph.appendChild(textNode);

  document.body.appendChild(newParagraph);
}

Specifications

Browser compatibility

See also

• WebRTC API
• A simple RTCDataChannel example
• Related events: open, close, and error
• RTCDataChannel.send()