chrome-extensions-samples/_archive/apps/samples/websocket-server/index.js

function $(id) {
  return document.getElementById(id);
}

function log(text) {
  $('log').value += text + '\n';
}

var port = 9999;
var isServer = false;
if (http.Server && http.WebSocketServer) {
  // Listen for HTTP connections.
  var server = new http.Server();
  var wsServer = new http.WebSocketServer(server);
  server.listen(port);
  isServer = true;

  server.addEventListener('request', function(req) {
    var url = req.headers.url;
    if (url == '/')
      url = '/index.html';
    // Serve the pages of this chrome application.
    req.serveUrl(url);
    return true;
  });

  // A list of connected websockets.
  var connectedSockets = [];

  wsServer.addEventListener('request', function(req) {
    log('Client connected');
    var socket = req.accept();
    connectedSockets.push(socket);

    // When a message is received on one socket, rebroadcast it on all
    // connected sockets.
    socket.addEventListener('message', function(e) {
      for (var i = 0; i < connectedSockets.length; i++)
        connectedSockets[i].send(e.data);
    });

    // When a socket is closed, remove it from the list of connected sockets.
    socket.addEventListener('close', function() {
      log('Client disconnected');
      for (var i = 0; i < connectedSockets.length; i++) {
        if (connectedSockets[i] == socket) {
          connectedSockets.splice(i, 1);
          break;
        }
      }
    });
    return true;
  });
}

document.addEventListener('DOMContentLoaded', function() {
  log('This is a test of an HTTP and WebSocket server. This application is ' +
      'serving its own source code on port ' + port + '. Each client ' +
      'connects to the server on a WebSocket and all messages received on ' +
      'one WebSocket are echoed to all connected clients - i.e. a chat ' +
      'server. Enjoy!');
// FIXME: Wait for 1s so that HTTP Server socket is listening...
setTimeout(function() {
  var address = isServer ? 'ws://localhost:' + port + '/' :
      window.location.href.replace('http', 'ws');
  var ws = new WebSocket(address);
  ws.addEventListener('open', function() {
    log('Connected');
  });
  ws.addEventListener('close', function() {
    log('Connection lost');
    $('input').disabled = true;
  });
  ws.addEventListener('message', function(e) {
    log(e.data);
  });
  $('input').addEventListener('keydown', function(e) {
    if (ws && ws.readyState == 1 && e.keyCode == 13) {
      ws.send(this.value);
      this.value = '';
    }
  });
}, 1e3);
});