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.
Note: Different browsers have different limitations on the size of the message you can send. Specifications exist to define how to automatically fragment large messages, but not all browsers implement them, and those that do have various additional restrictions. This will get less complicated over time, but for now, if you have questions, see Understanding message size limits in Using WebRTC data channels.
Syntax
RTCDataChannel.send(data);
Parameters
data
-
The data to transmit across the connection. This may be a
USVString
, aBlob
, anArrayBuffer
, or anArrayBufferView
.
Return value
undefined
.
Exceptions
InvalidStateError
DOMException
-
Thrown when the data channel has not finished establishing its own connection (that is, its
readyState
isconnecting
). The data channel must establish its own connection because it uses a transport channel separate from that of the media content. This error occurs without sending or buffering thedata
. NetworkError
DOMException
-
Thrown when 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. TypeError
DOMException
-
Thrown if the specified
data
is too large for the other peer to receive. Since there are multiple techniques for breaking up large data into smaller pieces for transfer, it's possible to encounter scenarios in which the other peer does not support the same ones. For example, if one peer is a modern browser that supports using theEOR
(End of Record) flag to indicate when a received message is the last piece of a multi-part object sent usingsend()
. For more information about message size restrictions, see Understanding message size limits in Using WebRTC data channels.
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
Specification |
---|
WebRTC 1.0: Real-Time Communication Between Browsers # dom-rtcdatachannel-send |
Browser compatibility
BCD tables only load in the browser