WebSocket class abstract

A two-way communication object for WebSocket clients. Establishes a WebSocket connection, sends data or streams of data to the server, and receives data from the server.

This class mirrors the native Dart WebSocket API from the dart:io library. The benefit is that it's platform agnostic and can be used on the server or in the browser - so you can write libraries or APIs that can run in either place just by building them on WebSocket.

To establish a connection, use the static connect method:

import 'package:w_transport/w_transport.dart';

main() async {
  Uri uri = Uri.parse('ws://echo.websocket.org');
  WSocket webSocket = await WSocket.connect(uri);
}

Once the connection has been established, data can be sent to server and the connection can be listened to. WSocket is a stream and a stream sink, so sending and receiving data is the same as interacting with a sink and a stream, respectively.

Uri uri = Uri.parse('ws://echo.websocket.org');
WSocket webSocket = await WSocket.connect(uri);

// Send data
String data = 'data';
Stream stream = ...;
webSocket.add(data);
webSocket.addStream(stream);

// Receive data
webSocket.listen((data) {
  print(data);
});

Finally, you can determine when the web socket connection has been closed in a few different ways:

Uri uri = Uri.parse('ws://echo.websocket.org');
WSocket webSocket = await WSocket.connect(uri);

// "done" is a Future
webSocket.done.then((_) { ... });

// calling "close()" returns the same Future
webSocket.close().then((_) { ... });

// registering an "onDone()" handler also works
webSocket.listen((_) {}, onDone: () { ... });

Note: In order to leverage SockJS, you will need to load the sockjs.js library first. See https://github.com/workiva/sockjs_client_wrapper#usage

Implemented types

Implementers

MockWSocket

Constructors

WebSocket()

Properties

closeCode → int?: The close code set when the WebSocket connection is closed. If there is no close code available this property will be null.
no setter
closeReason → String?: The close reason set when the WebSocket connection is closed. If there is no close reason available this property will be null.
no setter
done → Future<Null>: Future that resolves when this WebSocket connection has completely closed.
no setteroverride
first → Future: The first element of this stream.
no setterinherited
hashCode → int: The hash code for this object.
no setterinherited
isBroadcast → bool: Whether this stream is a broadcast stream.
no setterinherited
isEmpty → Future<bool>: Whether this stream contains any elements.
no setterinherited
last → Future: The last element of this stream.
no setterinherited
length → Future<int>: The number of elements in this stream.
no setterinherited
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
single → Future: The single element of this stream.
no setterinherited

Methods

add(dynamic message) → void: Sends a message over the WebSocket connection.
override
addError(Object errorEvent, [StackTrace? stackTrace]) → void: Add an error to the sink. This will cause the WebSocket connection to close.
override
addStream(Stream stream) → Future<Null>: Adds a stream of data to send over the WebSocket connection. This will wait for the stream to complete, sending each element as it is received.
override
any(bool test(dynamic element)) → Future<bool>: Checks whether test accepts any element provided by this stream.
inherited
asBroadcastStream({void onListen(StreamSubscription subscription)?, void onCancel(StreamSubscription subscription)?}) → Stream: Returns a multi-subscription stream that produces the same events as this.
inherited
asyncExpand<E>(Stream<E>? convert(dynamic event)) → Stream<E>: Transforms each element into a sequence of asynchronous events.
inherited
asyncMap<E>(FutureOr<E> convert(dynamic event)) → Stream<E>: Creates a new stream with each data event of this stream asynchronously mapped to a new event.
inherited
cast<R>() → Stream<R>: Adapt this stream to be a Stream<R>.
inherited
close([int? code, String? reason]) → Future<Null>: Closes the WebSocket connection. Optionally set code and reason to send close information to the remote peer.
override
contains(Object? needle) → Future<bool>: Returns whether needle occurs in the elements provided by this stream.
inherited
distinct([bool equals(dynamic previous, dynamic next)?]) → Stream: Skips data events if they are equal to the previous data event.
inherited
drain<E>([E? futureValue]) → Future<E>: Discards all data on this stream, but signals when it is done or an error occurred.
inherited
elementAt(int index) → Future: Returns the value of the indexth data event of this stream.
inherited
every(bool test(dynamic element)) → Future<bool>: Checks whether test accepts all elements provided by this stream.
inherited
expand<S>(Iterable<S> convert(dynamic element)) → Stream<S>: Transforms each element of this stream into a sequence of elements.
inherited
firstWhere(bool test(dynamic element), {dynamic orElse()?}) → Future: Finds the first element of this stream matching test.
inherited
fold<S>(S initialValue, S combine(S previous, dynamic element)) → Future<S>: Combines a sequence of values by repeatedly applying combine.
inherited
forEach(void action(dynamic element)) → Future<void>: Executes action on each element of this stream.
inherited
handleError(Function onError, {bool test(dynamic error)?}) → Stream: Creates a wrapper Stream that intercepts some errors from this stream.
inherited
join([String separator = ""]) → Future<String>: Combines the string representation of elements into a single string.
inherited
lastWhere(bool test(dynamic element), {dynamic orElse()?}) → Future: Finds the last element in this stream matching test.
inherited
listen(void onData(dynamic event)?, {Function? onError, void onDone()?, bool? cancelOnError}) → StreamSubscription: Adds a subscription to this stream.
inherited
map<S>(S convert(dynamic event)) → Stream<S>: Transforms each element of this stream into a new stream event.
inherited
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
pipe(StreamConsumer streamConsumer) → Future: Pipes the events of this stream into streamConsumer.
inherited
reduce(dynamic combine(dynamic previous, dynamic element)) → Future: Combines a sequence of values by repeatedly applying combine.
inherited
singleWhere(bool test(dynamic element), {dynamic orElse()?}) → Future: Finds the single element in this stream matching test.
inherited
skip(int count) → Stream: Skips the first count data events from this stream.
inherited
skipWhile(bool test(dynamic element)) → Stream: Skip data events from this stream while they are matched by test.
inherited
take(int count) → Stream: Provides at most the first count data events of this stream.
inherited
takeWhile(bool test(dynamic element)) → Stream: Forwards data events while test is successful.
inherited
timeout(Duration timeLimit, {void onTimeout(EventSink sink)?}) → Stream: Creates a new stream with the same events as this stream.
inherited
toList() → Future<List>: Collects all elements of this stream in a List.
inherited
toSet() → Future<Set>: Collects the data of this stream in a Set.
inherited
toString() → String: A string representation of this object.
inherited
transform<S>(StreamTransformer<dynamic, S> streamTransformer) → Stream<S>: Applies streamTransformer to this stream.
inherited
where(bool test(dynamic event)) → Stream: Creates a new stream from this stream that discards some elements.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Static Methods

connect(Uri uri, {Map<String, dynamic>? headers, Iterable<String>? protocols, TransportPlatform? transportPlatform}) → Future<WebSocket?>: Create a new WebSocket connection. The given uri must use the scheme ws or wss.
getGlobalEventMonitor() → GlobalWebSocketMonitor: Returns a monitor that provides streams of events for all WebSockets constructed via w_transport.