WebSocket test

index.html

<!-- Copyright 2015 the Dart project authors. All rights reserved.
     Use of this source code is governed by a BSD-style license
     that can be found in the LICENSE file. -->

<h2>A WebSocket test using echo.websocket.org</h2>

<br>

<p>Enter text to echo:</p>

<input type="text">

main.dart

// Copyright 2012 the Dart project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file.

import 'dart:html';

void main() {
  var wsTest = WebSocketTest('wss://echo.websocket.org');

  InputElement input = querySelector('input');
  input.onChange.listen((_) {
    wsTest.send(input.value);
    input.value = '';
  });
}

class WebSocketTest {
  final WebSocket _socket;
  final _timer = Stopwatch()..start();

  WebSocketTest(String url) : _socket = WebSocket(url) {
    print('Connecting to $url...');
    _startListening();
  }

  void send(String value) {
    print('==> $value');
    _socket.send(value);
    _timer.reset();
  }

  void _startListening() {
    _socket.onOpen.listen((e) {
      print('Connected!');
      send('Hello from Dart!');
    });

    _socket.onClose.listen((_) => print('Websocket closed.'));
    _socket.onError.listen((_) => print('Error opening connection.'));

    _socket.onMessage.listen((e) {
      print('<== ${e.data} [${_timer.elapsedMilliseconds}ms]');
    });
  }
}

styles.css

/* Copyright 2015 the Dart project authors. All rights reserved. */
/* Use of this source code is governed by a BSD-style license */
/* that can be found in the LICENSE file. */

input {
  width: 250px;
  margin-left: 2em;
}