WebSocketTransformer class Null safety

The WebSocketTransformer provides the ability to upgrade a HttpRequest to a WebSocket connection. It supports both upgrading a single HttpRequest and upgrading a stream of HttpRequests.

To upgrade a single HttpRequest use the static upgrade method.

HttpServer server;
server.listen((request) {
  if (...) {
    WebSocketTransformer.upgrade(request).then((websocket) {
  } else {
    // Do normal HTTP request processing.

To transform a stream of HttpRequest events as it implements a stream transformer that transforms a stream of HttpRequest into a stream of WebSockets by upgrading each HttpRequest from the HTTP or HTTPS server, to the WebSocket protocol.

server.transform(new WebSocketTransformer()).listen((webSocket) => ...);

This transformer strives to implement WebSockets as specified by RFC6455.

Implemented types


WebSocketTransformer({dynamic protocolSelector(List<String> protocols)?, CompressionOptions compression = CompressionOptions.compressionDefault})
Create a new WebSocketTransformer.


hashCode int
The hash code for this object.
runtimeType Type
A representation of the runtime type of the object.


bind(Stream<HttpRequest> stream) Stream<WebSocket>
Transforms the provided stream.
cast<RS, RT>() StreamTransformer<RS, RT>
Provides a StreamTransformer<RS, RT> view of this stream transformer.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
toString() String
A string representation of this object.


operator ==(Object other) bool
The equality operator.

Static Methods

isUpgradeRequest(HttpRequest request) bool
Checks whether the request is a valid WebSocket upgrade request.
upgrade(HttpRequest request, {dynamic protocolSelector(List<String> protocols)?, CompressionOptions compression = CompressionOptions.compressionDefault}) Future<WebSocket>
Upgrades an HttpRequest to a WebSocket connection. If the request is not a valid WebSocket upgrade request an HTTP response with status code 500 will be returned. Otherwise the returned future will complete with the WebSocket when the upgrade process is complete.