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';

const echoUrl = 'wss://echo.websocket.org';

void main() {
  WebSocketTest wsTest = new WebSocketTest(echoUrl);

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

class WebSocketTest {
  WebSocket _socket;
  Stopwatch _timer;

  WebSocketTest(String url) {
    print("Connecting to ${url}…");
    _socket = new WebSocket(url);
    _startListening();
  }

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

  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((MessageEvent 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;
}