websocket.js

/**
 * socket.io
 * Copyright(c) 2011 LearnBoost <dev@learnboost.com>
 * MIT Licensed
 */

(function (exports, io, global) {

  /**
   * Expose constructor.
   */

  exports.websocket = WS;

  /**
   * The WebSocket transport uses the HTML5 WebSocket API to establish an
   * persistent connection with the Socket.IO server. This transport will also
   * be inherited by the FlashSocket fallback as it provides a API compatible
   * polyfill for the WebSockets.
   *
   * @constructor
   * @extends {io.Transport}
   * @api public
   */

  function WS (socket) {
    io.Transport.apply(this, arguments);
  };

  /**
   * Inherits from Transport.
   */

  io.util.inherit(WS, io.Transport);

  /**
   * Transport name
   *
   * @api public
   */

  WS.prototype.name = 'websocket';

  /**
   * Initializes a new `WebSocket` connection with the Socket.IO server. We attach
   * all the appropriate listeners to handle the responses from the server.
   *
   * @returns {Transport}
   * @api public
   */

  WS.prototype.open = function () {
    var query = io.util.query(this.socket.options.query)
      , self = this
      , Socket

    // if node
    Socket = require('ws');
    // end node

    if (!Socket) {
      Socket = global.MozWebSocket || global.WebSocket;
    }

    this.websocket = new Socket(this.prepareUrl() + query);

    this.websocket.onopen = function () {
      self.onOpen();
      self.socket.setBuffer(false);
    };
    this.websocket.onmessage = function (ev) {
      self.onData(ev.data);
    };
    this.websocket.onclose = function () {
      var isWebsocketClose = false;
      for (var socketKey in window.io.sockets){
        var socket = window.io.sockets[socketKey];
        if (socket.transport.name == self.name){
          isWebsocketClose = true;
          break;
        }
      }
      if (isWebsocketClose){
        self.onClose();
        self.socket.setBuffer(true);
      }
    };
    this.websocket.onerror = function (e) {
      self.onError(e);
    };

    return this;
  };

  /**
   * Send a message to the Socket.IO server. The message will automatically be
   * encoded in the correct message format.
   *
   * @returns {Transport}
   * @api public
   */

  WS.prototype.send = function (data) {
    this.websocket.send(data);
    return this;
  };

  /**
   * Payload
   *
   * @api private
   */

  WS.prototype.payload = function (arr) {
    for (var i = 0, l = arr.length; i < l; i++) {
      this.packet(arr[i]);
    }
    return this;
  };

  /**
   * Disconnect the established `WebSocket` connection.
   *
   * @returns {Transport}
   * @api public
   */

  WS.prototype.close = function () {
    this.websocket.close();
    return this;
  };

  /**
   * Handle the errors that `WebSocket` might be giving when we
   * are attempting to connect or send messages.
   *
   * @param {Error} e The error.
   * @api private
   */

  WS.prototype.onError = function (e) {
    this.socket.onError(e);
  };

  /**
   * Returns the appropriate scheme for the URI generation.
   *
   * @api private
   */
  WS.prototype.scheme = function () {
    return this.socket.options.secure ? 'wss' : 'ws';
  };

  /**
   * Checks if the browser has support for native `WebSockets` and that
   * it's not the polyfill created for the FlashSocket transport.
   *
   * @return {Boolean}
   * @api public
   */

  WS.check = function () {
    // if node
    return true;
    // end node
    return ('WebSocket' in global && !('__addTask' in WebSocket))
          || 'MozWebSocket' in global;
  };

  /**
   * Check if the `WebSocket` transport support cross domain communications.
   *
   * @returns {Boolean}
   * @api public
   */

  WS.xdomainCheck = function () {
    return true;
  };

  /**
   * Add the transport to your public io.transports array.
   *
   * @api private
   */

  io.transports.push('websocket');

})(
    'undefined' != typeof io ? io.Transport : module.exports
  , 'undefined' != typeof io ? io : module.parent.exports
  , this
);