WebTransport: datagrams property
The datagrams
read-only property of the WebTransport
interface returns a WebTransportDatagramDuplexStream
instance that can be used to send and receive datagrams — unreliable data transmission.
"Unreliable" means that transmission of data is not guaranteed, nor is arrival in a specific order. This is fine in some situations and provides very fast delivery. For example, you might want to transmit regular game state updates where each message supersedes the last one that arrives, and order is not important.
Note: This feature is available in Web Workers
Value
A WebTransportDatagramDuplexStream
object.
Examples
Writing an outgoing datagram
The WebTransportDatagramDuplexStream.writable
property returns a WritableStream
object that you can write data to using a writer, for transmission to the server:
js
const writer = transport.datagrams.writable.getWriter();
const data1 = new Uint8Array([65, 66, 67]);
const data2 = new Uint8Array([68, 69, 70]);
writer.write(data1);
writer.write(data2);
Reading an incoming datagram
The WebTransportDatagramDuplexStream.readable
property returns a ReadableStream
object that you can use to receive data from the server:
js
async function readData() {
const reader = transport.datagrams.readable.getReader();
while (true) {
const { value, done } = await reader.read();
if (done) {
break;
}
// value is a Uint8Array.
console.log(value);
}
}
Specifications
Specification |
---|
WebTransport # dom-webtransport-datagrams |
Browser compatibility
BCD tables only load in the browser