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.on.message.add((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 WebSocketEvents.

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

@DocsEditable
/**
* 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.on.message.add((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 [WebSocketEvents].
*
* For more information, see the
* [WebSockets](http://www.dartlang.org/docs/library-tour/#html-websockets)
* section of the library tour and
* [Introducing WebSockets](http://www.html5rocks.com/en/tutorials/websockets/basics/),
* an HTML5Rocks.com tutorial.
*/
@DomName('WebSocket')
@SupportedBrowser(SupportedBrowser.CHROME)
@SupportedBrowser(SupportedBrowser.FIREFOX)
@SupportedBrowser(SupportedBrowser.IE, '10')
@SupportedBrowser(SupportedBrowser.SAFARI)
class WebSocket extends EventTarget native "WebSocket" {

 @DomName('WebSocket.closeEvent')
 @DocsEditable
 static const EventStreamProvider<CloseEvent> closeEvent = const EventStreamProvider<CloseEvent>('close');

 @DomName('WebSocket.errorEvent')
 @DocsEditable
 static const EventStreamProvider<Event> errorEvent = const EventStreamProvider<Event>('error');

 @DomName('WebSocket.messageEvent')
 @DocsEditable
 static const EventStreamProvider<MessageEvent> messageEvent = const EventStreamProvider<MessageEvent>('message');

 @DomName('WebSocket.openEvent')
 @DocsEditable
 static const EventStreamProvider<Event> openEvent = const EventStreamProvider<Event>('open');

 @DomName('WebSocket.WebSocket')
 @DocsEditable
 factory WebSocket(String url, [protocol_OR_protocols]) {
   if ((url is String || url == null) && !?protocol_OR_protocols) {
     return WebSocket._create_1(url);
   }
   if ((url is String || url == null) && (protocol_OR_protocols is List<String> || protocol_OR_protocols == null)) {
     return WebSocket._create_2(url, protocol_OR_protocols);
   }
   if ((url is String || url == null) && (protocol_OR_protocols is String || protocol_OR_protocols == null)) {
     return WebSocket._create_3(url, protocol_OR_protocols);
   }
   throw new ArgumentError("Incorrect number or type of arguments");
 }
 static WebSocket _create_1(url) => JS('WebSocket', 'new WebSocket(#)', url);
 static WebSocket _create_2(url, protocol_OR_protocols) => JS('WebSocket', 'new WebSocket(#,#)', url, protocol_OR_protocols);
 static WebSocket _create_3(url, protocol_OR_protocols) => JS('WebSocket', 'new WebSocket(#,#)', url, protocol_OR_protocols);

 /// Checks if this type is supported on the current platform.
 static bool get supported => JS('bool', 'typeof window.WebSocket != "undefined"');

 @DomName('WebSocket.CLOSED')
 @DocsEditable
 static const int CLOSED = 3;

 @DomName('WebSocket.CLOSING')
 @DocsEditable
 static const int CLOSING = 2;

 @DomName('WebSocket.CONNECTING')
 @DocsEditable
 static const int CONNECTING = 0;

 @DomName('WebSocket.OPEN')
 @DocsEditable
 static const int OPEN = 1;

 @JSName('URL')
 @DomName('WebSocket.URL')
 @DocsEditable
 final String Url;

 @DomName('WebSocket.binaryType')
 @DocsEditable
 String binaryType;

 @DomName('WebSocket.bufferedAmount')
 @DocsEditable
 final int bufferedAmount;

 @DomName('WebSocket.extensions')
 @DocsEditable
 final String extensions;

 @DomName('WebSocket.protocol')
 @DocsEditable
 final String protocol;

 @DomName('WebSocket.readyState')
 @DocsEditable
 final int readyState;

 @DomName('WebSocket.url')
 @DocsEditable
 final String url;

 @JSName('addEventListener')
 @DomName('WebSocket.addEventListener')
 @DocsEditable
 void $dom_addEventListener(String type, EventListener listener, [bool useCapture]) native;

 @DomName('WebSocket.close')
 @DocsEditable
 void close([int code, String reason]) native;

 @DomName('WebSocket.dispatchEvent')
 @DocsEditable
 bool dispatchEvent(Event evt) native;

 @JSName('removeEventListener')
 @DomName('WebSocket.removeEventListener')
 @DocsEditable
 void $dom_removeEventListener(String type, EventListener listener, [bool useCapture]) native;

 @DomName('WebSocket.send')
 @DocsEditable
 void send(data) native;

 @DomName('WebSocket.onclose')
 @DocsEditable
 Stream<CloseEvent> get onClose => closeEvent.forTarget(this);

 @DomName('WebSocket.onerror')
 @DocsEditable
 Stream<Event> get onError => errorEvent.forTarget(this);

 @DomName('WebSocket.onmessage')
 @DocsEditable
 Stream<MessageEvent> get onMessage => messageEvent.forTarget(this);

 @DomName('WebSocket.onopen')
 @DocsEditable
 Stream<Event> get onOpen => openEvent.forTarget(this);
}