WebSocket#

class WebSocket extends EventTarget

Annotations: @SupportedBrowser.new(SupportedBrowser.CHROME), @SupportedBrowser.new(SupportedBrowser.FIREFOX), @SupportedBrowser.new(SupportedBrowser.IE, '10'), @SupportedBrowser.new(SupportedBrowser.SAFARI), @Unstable.new(), @Native.new("WebSocket")

Use the WebSocket interface to connect to a WebSocket, and to send and receive data on that WebSocket.

To use a WebSocket in your web app, first create a WebSocket object, passing the WebSocket URL as an argument to the constructor.

var webSocket = new WebSocket('ws://127.0.0.1:1337/ws');

To send data on the WebSocket, use the send method.

if (webSocket != null && webSocket.readyState == WebSocket.OPEN) {
  webSocket.send(data);
} else {
  print('WebSocket not connected, message $data not sent');
}

To receive data on the WebSocket, register a listener for message events.

webSocket.onMessage.listen((MessageEvent e) {
  receivedData(e.data);
});

The message event handler receives a MessageEvent object as its sole argument. You can also define open, close, and error handlers, as specified by Events.

For more information, see the WebSockets section of the library tour and Introducing WebSockets, an HTML5Rocks.com tutorial.

Inheritance

Object → EventTarget → WebSocket

Constructors#

WebSocket() factory#

factory WebSocket(String url, [ Object? protocols])

Implementation

factory WebSocket(String url, [Object? protocols]) {
  if (protocols != null) {
    return WebSocket._create_1(url, protocols);
  }
  return WebSocket._create_2(url);
}

Properties#

binaryType read / write#

String? get binaryType

Implementation

String? get binaryType native;

set binaryType(String? value) native;

bufferedAmount no setter#

int? get bufferedAmount

Implementation

int? get bufferedAmount native;

extensions no setter#

String? get extensions

Implementation

String? get extensions native;

hashCode no setter inherited#

int get hashCode

Inherited from Interceptor.

Implementation

int get hashCode => Primitives.objectHashCode(this);

on no setter inherited#

Events get on

This is an ease-of-use accessor for event streams which should only be used when an explicit accessor is not available.

Inherited from EventTarget.

Implementation

Events get on => new Events(this);

onClose no setter#

Stream<CloseEvent> get onClose

Stream of close events handled by this WebSocket.

Implementation

Stream<CloseEvent> get onClose => closeEvent.forTarget(this);

onError no setter#

Stream<Event> get onError

Stream of error events handled by this WebSocket.

Implementation

Stream<Event> get onError => errorEvent.forTarget(this);

onMessage no setter#

Stream<MessageEvent> get onMessage

Stream of message events handled by this WebSocket.

Implementation

Stream<MessageEvent> get onMessage => messageEvent.forTarget(this);

onOpen no setter#

Stream<Event> get onOpen

Stream of open events handled by this WebSocket.

Implementation

Stream<Event> get onOpen => openEvent.forTarget(this);

protocol no setter#

String? get protocol

Implementation

String? get protocol native;

readyState no setter#

int get readyState

Implementation

int get readyState native;

runtimeType no setter inherited#

Type get runtimeType

Inherited from Interceptor.

Implementation

Type get runtimeType =>
    getRuntimeTypeOfInterceptorNotArray(getInterceptor(this), this);

url no setter#

String? get url

Implementation

String? get url native;

Methods#

addEventListener() inherited#

void addEventListener( String type, dynamic Function(Event event)? listener, [ bool? useCapture, ]);

Inherited from EventTarget.

Implementation

void addEventListener(
  String type,
  EventListener? listener, [
  bool? useCapture,
]) {
  &#47;&#47; TODO(leafp): This check is avoid a bug in our dispatch code when
  &#47;&#47; listener is null.  The browser treats this call as a no-op in this
  &#47;&#47; case, so it's fine to short-circuit it, but we should not have to.
  if (listener != null) {
    _addEventListener(type, listener, useCapture);
  }
}

close()#

void close([ int? code, String? reason])

Implementation

void close([int? code, String? reason]) native;

dispatchEvent() inherited#

bool dispatchEvent(Event event)

Inherited from EventTarget.

Implementation

bool dispatchEvent(Event event) native;

noSuchMethod() inherited#

dynamic noSuchMethod(Invocation invocation)

Invoked when a nonexistent method or property is accessed.

A dynamic member invocation can attempt to call a member which doesn't exist on the receiving object. Example:

dynamic object = 1;
object.add(42); // Statically allowed, run-time error

This invalid code will invoke the noSuchMethod method of the integer 1 with an Invocation representing the .add(42) call and arguments (which then throws).

Classes can override noSuchMethod to provide custom behavior for such invalid dynamic invocations.

A class with a non-default noSuchMethod invocation can also omit implementations for members of its interface. Example:

class MockList<T> implements List<T> {
  noSuchMethod(Invocation invocation) {
    log(invocation);
    super.noSuchMethod(invocation); // Will throw.
  }
}
void main() {
  MockList().add(42);
}

This code has no compile-time warnings or errors even though the MockList class has no concrete implementation of any of the List interface methods. Calls to List methods are forwarded to noSuchMethod, so this code will log an invocation similar to Invocation.method(#add, [42]) and then throw.

If a value is returned from noSuchMethod, it becomes the result of the original invocation. If the value is not of a type that can be returned by the original invocation, a type error occurs at the invocation.

The default behavior is to throw a NoSuchMethodError.

Inherited from Interceptor.

Implementation

dynamic noSuchMethod(Invocation invocation) {
  throw NoSuchMethodError.withInvocation(this, invocation);
}

removeEventListener() inherited#

void removeEventListener( String type, dynamic Function(Event event)? listener, [ bool? useCapture, ]);

Inherited from EventTarget.

Implementation

void removeEventListener(
  String type,
  EventListener? listener, [
  bool? useCapture,
]) {
  &#47;&#47; TODO(leafp): This check is avoid a bug in our dispatch code when
  &#47;&#47; listener is null.  The browser treats this call as a no-op in this
  &#47;&#47; case, so it's fine to short-circuit it, but we should not have to.
  if (listener != null) {
    _removeEventListener(type, listener, useCapture);
  }
}