WebTransport: protocol property
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
Note: This feature is available in Web Workers.
The protocol read-only property of the WebTransport interface returns the application-specific protocol selected by the server.
The value is selected from those offered in the protocols constructor option.
Note that the value is set once the ready promise fulfills.
It is the empty string if protocols was not used, or if the server chose not to select one of the offered protocols.
Value
A string.
Defaults to "".
Examples
Requesting and reading a negotiated protocol
This example shows how to request a set of candidate protocols and read back the one the server selected.
js
const url = "https://example.com:4999/wt";
async function initTransport(url) {
const transport = new WebTransport(url, {
protocols: ["chat", "file-transfer"],
});
try {
// The connection can be used once ready fulfills
await transport.ready;
console.log(transport.protocol); // e.g. "chat", or "" if none was selected
return transport;
} catch (error) {
// Ready may reject if the offered protocols aren't supported
console.error(`Connection failed: ${error}`);
}
}
initTransport(url);
Specifications
| Specification |
|---|
| WebTransport # dom-webtransport-protocol |