RTCDataChannel.send()

The send() method of the RTCDataChannel interface sends data across the data channel to the remote peer. This can be done any time except during the initial process of creating the underlying transport channel. Data sent before connecting is buffered if possible (or an error occurs if it's not possible), and is also buffered if sent while the connection is closing or closed.

Syntax

RTCDataChannel.send(data);

Parameters

data

The data to transmit across the connection. This may be a USVString, a Blob, an ArrayBuffer, or an ArrayBufferView.

Exceptions

InvalidStateError

Since the data channel uses a separate transport channel from the media content, it must establish its own connection; if it hasn't finished doing so (that is, its readyState is "connecting"), this error occurs without sending or buffering the data.

NetworkError

The specified data would need to be buffered, and there isn't room for it in the buffer. In this scenario, the underlying transport is immediately closed.

Example

In this example, a routine called sendMessage() is created; it accepts an object as input and sends to the remote peer, over the RTCDataChannel, a JSON string with the specified object and a time stamp.

var pc = new RTCPeerConnection();
var dc = pc.createDataChannel("BackChannel");

function sendMessage(msg) {
  let obj = {
    "message": msg,
    "timestamp": new Date()
  }
  dc.send(JSON.stringify(obj));
}

Specifications

Browser compatibility

[1] The interface is called DataChannel and not RTCDataChannel in Firefox. However, a binding has been in place since Firefox 24 so that either name will work.

[2] WebRTC was available behind a flag in Chrome 28 for Android, and was enabled by default starting in Chrome 29.

See also

• WebRTC
• RTCDataChannel
• RTCDataChannel.readyState
• close event