Engine.IO data loss on iOS devices

client.js

(function () {
  var container = document.getElementById('container');
  var socket = new eio('http://192.168.0.197:3000/', {
    transports: [ 'websocket' ]
  });

  socket.on('data', function (data) {
    var p = document.createElement('p');

    p.textContent = data;
    container.appendChild(p);
  });
  socket.on('close', function () {
    var p = document.createElement('p');

    p.textContent = 'close';
    container.appendChild(p);
  });
})();

engine.io.js

!function(e){if("object"==typeof exports&&"undefined"!=typeof module)module.exports=e();else if("function"==typeof define&&define.amd)define([],e);else{var f;"undefined"!=typeof window?f=window:"undefined"!=typeof global?f=global:"undefined"!=typeof self&&(f=self),f.eio=e()}}(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(_dereq_,module,exports){

module.exports =  _dereq_('./lib/');

},{"./lib/":2}],2:[function(_dereq_,module,exports){

module.exports = _dereq_('./socket');

/**
 * Exports parser
 *
 * @api public
 *
 */
module.exports.parser = _dereq_('engine.io-parser');

},{"./socket":3,"engine.io-parser":17}],3:[function(_dereq_,module,exports){
(function (global){
/**
 * Module dependencies.
 */

var transports = _dereq_('./transports');
var Emitter = _dereq_('component-emitter');
var debug = _dereq_('debug')('engine.io-client:socket');
var index = _dereq_('indexof');
var parser = _dereq_('engine.io-parser');
var parseuri = _dereq_('parseuri');
var parsejson = _dereq_('parsejson');
var parseqs = _dereq_('parseqs');

/**
 * Module exports.
 */

module.exports = Socket;

/**
 * Noop function.
 *
 * @api private
 */

function noop(){}

/**
 * Socket constructor.
 *
 * @param {String|Object} uri or options
 * @param {Object} options
 * @api public
 */

function Socket(uri, opts){
  if (!(this instanceof Socket)) return new Socket(uri, opts);

  opts = opts || {};

  if (uri && 'object' == typeof uri) {
    opts = uri;
    uri = null;
  }

  if (uri) {
    uri = parseuri(uri);
    opts.host = uri.host;
    opts.secure = uri.protocol == 'https' || uri.protocol == 'wss';
    opts.port = uri.port;
    if (uri.query) opts.query = uri.query;
  }

  this.secure = null != opts.secure ? opts.secure :
    (global.location && 'https:' == location.protocol);

  if (opts.host) {
    var pieces = opts.host.split(':');
    opts.hostname = pieces.shift();
    if (pieces.length) {
      opts.port = pieces.pop();
    } else if (!opts.port) {
      // if no port is specified manually, use the protocol default
      opts.port = this.secure ? '443' : '80';
    }
  }

  this.agent = opts.agent || false;
  this.hostname = opts.hostname ||
    (global.location ? location.hostname : 'localhost');
  this.port = opts.port || (global.location && location.port ?
       location.port :
       (this.secure ? 443 : 80));
  this.query = opts.query || {};
  if ('string' == typeof this.query) this.query = parseqs.decode(this.query);
  this.upgrade = false !== opts.upgrade;
  this.path = (opts.path || '/engine.io').replace(/\/$/, '') + '/';
  this.forceJSONP = !!opts.forceJSONP;
  this.jsonp = false !== opts.jsonp;
  this.forceBase64 = !!opts.forceBase64;
  this.enablesXDR = !!opts.enablesXDR;
  this.timestampParam = opts.timestampParam || 't';
  this.timestampRequests = opts.timestampRequests;
  this.transports = opts.transports || ['polling', 'websocket'];
  this.readyState = '';
  this.writeBuffer = [];
  this.callbackBuffer = [];
  this.policyPort = opts.policyPort || 843;
  this.rememberUpgrade = opts.rememberUpgrade || false;
  this.binaryType = null;
  this.onlyBinaryUpgrades = opts.onlyBinaryUpgrades;

  // SSL options for Node.js client
  this.pfx = opts.pfx || null;
  this.key = opts.key || null;
  this.passphrase = opts.passphrase || null;
  this.cert = opts.cert || null;
  this.ca = opts.ca || null;
  this.ciphers = opts.ciphers || null;
  this.rejectUnauthorized = opts.rejectUnauthorized || null;

  this.open();
}

Socket.priorWebsocketSuccess = false;

/**
 * Mix in `Emitter`.
 */

Emitter(Socket.prototype);

/**
 * Protocol version.
 *
 * @api public
 */

Socket.protocol = parser.protocol; // this is an int

/**
 * Expose deps for legacy compatibility
 * and standalone browser access.
 */

Socket.Socket = Socket;
Socket.Transport = _dereq_('./transport');
Socket.transports = _dereq_('./transports');
Socket.parser = _dereq_('engine.io-parser');

/**
 * Creates transport of the given type.
 *
 * @param {String} transport name
 * @return {Transport}
 * @api private
 */

Socket.prototype.createTransport = function (name) {
  debug('creating transport "%s"', name);
  var query = clone(this.query);

  // append engine.io protocol identifier
  query.EIO = parser.protocol;

  // transport name
  query.transport = name;

  // session id if we already have one
  if (this.id) query.sid = this.id;

  var transport = new transports[name]({
    agent: this.agent,
    hostname: this.hostname,
    port: this.port,
    secure: this.secure,
    path: this.path,
    query: query,
    forceJSONP: this.forceJSONP,
    jsonp: this.jsonp,
    forceBase64: this.forceBase64,
    enablesXDR: this.enablesXDR,
    timestampRequests: this.timestampRequests,
    timestampParam: this.timestampParam,
    policyPort: this.policyPort,
    socket: this,
    pfx: this.pfx,
    key: this.key,
    passphrase: this.passphrase,
    cert: this.cert,
    ca: this.ca,
    ciphers: this.ciphers,
    rejectUnauthorized: this.rejectUnauthorized
  });

  return transport;
};

function clone (obj) {
  var o = {};
  for (var i in obj) {
    if (obj.hasOwnProperty(i)) {
      o[i] = obj[i];
    }
  }
  return o;
}

/**
 * Initializes transport to use and starts probe.
 *
 * @api private
 */
Socket.prototype.open = function () {
  var transport;
  if (this.rememberUpgrade && Socket.priorWebsocketSuccess && this.transports.indexOf('websocket') != -1) {
    transport = 'websocket';
  } else if (0 == this.transports.length) {
    // Emit error on next tick so it can be listened to
    var self = this;
    setTimeout(function() {
      self.emit('error', 'No transports available');
    }, 0);
    return;
  } else {
    transport = this.transports[0];
  }
  this.readyState = 'opening';

  // Retry with the next transport if the transport is disabled (jsonp: false)
  var transport;
  try {
    transport = this.createTransport(transport);
  } catch (e) {
    this.transports.shift();
    this.open();
    return;
  }

  transport.open();
  this.setTransport(transport);
};

/**
 * Sets the current transport. Disables the existing one (if any).
 *
 * @api private
 */

Socket.prototype.setTransport = function(transport){
  debug('setting transport %s', transport.name);
  var self = this;

  if (this.transport) {
    debug('clearing existing transport %s', this.transport.name);
    this.transport.removeAllListeners();
  }

  // set up transport
  this.transport = transport;

  // set up transport listeners
  transport
  .on('drain', function(){
    self.onDrain();
  })
  .on('packet', function(packet){
    self.onPacket(packet);
  })
  .on('error', function(e){
    self.onError(e);
  })
  .on('close', function(){
    self.onClose('transport close');
  });
};

/**
 * Probes a transport.
 *
 * @param {String} transport name
 * @api private
 */

Socket.prototype.probe = function (name) {
  debug('probing transport "%s"', name);
  var transport = this.createTransport(name, { probe: 1 })
    , failed = false
    , self = this;

  Socket.priorWebsocketSuccess = false;

  function onTransportOpen(){
    if (self.onlyBinaryUpgrades) {
      var upgradeLosesBinary = !this.supportsBinary && self.transport.supportsBinary;
      failed = failed || upgradeLosesBinary;
    }
    if (failed) return;

    debug('probe transport "%s" opened', name);
    transport.send([{ type: 'ping', data: 'probe' }]);
    transport.once('packet', function (msg) {
      if (failed) return;
      if ('pong' == msg.type && 'probe' == msg.data) {
        debug('probe transport "%s" pong', name);
        self.upgrading = true;
        self.emit('upgrading', transport);
        if (!transport) return;
        Socket.priorWebsocketSuccess = 'websocket' == transport.name;

        debug('pausing current transport "%s"', self.transport.name);
        self.transport.pause(function () {
          if (failed) return;
          if ('closed' == self.readyState) return;
          debug('changing transport and sending upgrade packet');

          cleanup();

          self.setTransport(transport);
          transport.send([{ type: 'upgrade' }]);
          self.emit('upgrade', transport);
          transport = null;
          self.upgrading = false;
          self.flush();
        });
      } else {
        debug('probe transport "%s" failed', name);
        var err = new Error('probe error');
        err.transport = transport.name;
        self.emit('upgradeError', err);
      }
    });
  }

  function freezeTransport() {
    if (failed) return;

    // Any callback called by transport should be ignored since now
    failed = true;

    cleanup();

    transport.close();
    transport = null;
  }

  //Handle any error that happens while probing
  function onerror(err) {
    var error = new Error('probe error: ' + err);
    error.transport = transport.name;

    freezeTransport();

    debug('probe transport "%s" failed because of error: %s', name, err);

    self.emit('upgradeError', error);
  }

  function onTransportClose(){
    onerror("transport closed");
  }

  //When the socket is closed while we're probing
  function onclose(){
    onerror("socket closed");
  }

  //When the socket is upgraded while we're probing
  function onupgrade(to){
    if (transport && to.name != transport.name) {
      debug('"%s" works - aborting "%s"', to.name, transport.name);
      freezeTransport();
    }
  }

  //Remove all listeners on the transport and on self
  function cleanup(){
    transport.removeListener('open', onTransportOpen);
    transport.removeListener('error', onerror);
    transport.removeListener('close', onTransportClose);
    self.removeListener('close', onclose);
    self.removeListener('upgrading', onupgrade);
  }

  transport.once('open', onTransportOpen);
  transport.once('error', onerror);
  transport.once('close', onTransportClose);

  this.once('close', onclose);
  this.once('upgrading', onupgrade);

  transport.open();

};

/**
 * Called when connection is deemed open.
 *
 * @api public
 */

Socket.prototype.onOpen = function () {
  debug('socket open');
  this.readyState = 'open';
  Socket.priorWebsocketSuccess = 'websocket' == this.transport.name;
  this.emit('open');
  this.flush();

  // we check for `readyState` in case an `open`
  // listener already closed the socket
  if ('open' == this.readyState && this.upgrade && this.transport.pause) {
    debug('starting upgrade probes');
    for (var i = 0, l = this.upgrades.length; i < l; i++) {
      this.probe(this.upgrades[i]);
    }
  }
};

/**
 * Handles a packet.
 *
 * @api private
 */

Socket.prototype.onPacket = function (packet) {
  if ('opening' == this.readyState || 'open' == this.readyState) {
    debug('socket receive: type "%s", data "%s"', packet.type, packet.data);

    this.emit('packet', packet);

    // Socket is live - any packet counts
    this.emit('heartbeat');

    switch (packet.type) {
      case 'open':
        this.onHandshake(parsejson(packet.data));
        break;

      case 'pong':
        this.setPing();
        break;

      case 'error':
        var err = new Error('server error');
        err.code = packet.data;
        this.emit('error', err);
        break;

      case 'message':
        this.emit('data', packet.data);
        this.emit('message', packet.data);
        break;
    }
  } else {
    debug('packet received with socket readyState "%s"', this.readyState);
  }
};

/**
 * Called upon handshake completion.
 *
 * @param {Object} handshake obj
 * @api private
 */

Socket.prototype.onHandshake = function (data) {
  this.emit('handshake', data);
  this.id = data.sid;
  this.transport.query.sid = data.sid;
  this.upgrades = this.filterUpgrades(data.upgrades);
  this.pingInterval = data.pingInterval;
  this.pingTimeout = data.pingTimeout;
  this.onOpen();
  // In case open handler closes socket
  if  ('closed' == this.readyState) return;
  this.setPing();

  // Prolong liveness of socket on heartbeat
  this.removeListener('heartbeat', this.onHeartbeat);
  this.on('heartbeat', this.onHeartbeat);
};

/**
 * Resets ping timeout.
 *
 * @api private
 */

Socket.prototype.onHeartbeat = function (timeout) {
  clearTimeout(this.pingTimeoutTimer);
  var self = this;
  self.pingTimeoutTimer = setTimeout(function () {
    if ('closed' == self.readyState) return;
    self.onClose('ping timeout');
  }, timeout || (self.pingInterval + self.pingTimeout));
};

/**
 * Pings server every `this.pingInterval` and expects response
 * within `this.pingTimeout` or closes connection.
 *
 * @api private
 */

Socket.prototype.setPing = function () {
  var self = this;
  clearTimeout(self.pingIntervalTimer);
  self.pingIntervalTimer = setTimeout(function () {
    debug('writing ping packet - expecting pong within %sms', self.pingTimeout);
    self.ping();
    self.onHeartbeat(self.pingTimeout);
  }, self.pingInterval);
};

/**
* Sends a ping packet.
*
* @api public
*/

Socket.prototype.ping = function () {
  this.sendPacket('ping');
};

/**
 * Called on `drain` event
 *
 * @api private
 */

Socket.prototype.onDrain = function() {
  for (var i = 0; i < this.prevBufferLen; i++) {
    if (this.callbackBuffer[i]) {
      this.callbackBuffer[i]();
    }
  }

  this.writeBuffer.splice(0, this.prevBufferLen);
  this.callbackBuffer.splice(0, this.prevBufferLen);

  // setting prevBufferLen = 0 is very important
  // for example, when upgrading, upgrade packet is sent over,
  // and a nonzero prevBufferLen could cause problems on `drain`
  this.prevBufferLen = 0;

  if (this.writeBuffer.length == 0) {
    this.emit('drain');
  } else {
    this.flush();
  }
};

/**
 * Flush write buffers.
 *
 * @api private
 */

Socket.prototype.flush = function () {
  if ('closed' != this.readyState && this.transport.writable &&
    !this.upgrading && this.writeBuffer.length) {
    debug('flushing %d packets in socket', this.writeBuffer.length);
    this.transport.send(this.writeBuffer);
    // keep track of current length of writeBuffer
    // splice writeBuffer and callbackBuffer on `drain`
    this.prevBufferLen = this.writeBuffer.length;
    this.emit('flush');
  }
};

/**
 * Sends a message.
 *
 * @param {String} message.
 * @param {Function} callback function.
 * @return {Socket} for chaining.
 * @api public
 */

Socket.prototype.write =
Socket.prototype.send = function (msg, fn) {
  this.sendPacket('message', msg, fn);
  return this;
};

/**
 * Sends a packet.
 *
 * @param {String} packet type.
 * @param {String} data.
 * @param {Function} callback function.
 * @api private
 */

Socket.prototype.sendPacket = function (type, data, fn) {
  if ('closing' == this.readyState || 'closed' == this.readyState) {
    return;
  }

  var packet = { type: type, data: data };
  this.emit('packetCreate', packet);
  this.writeBuffer.push(packet);
  this.callbackBuffer.push(fn);
  this.flush();
};

/**
 * Closes the connection.
 *
 * @api private
 */

Socket.prototype.close = function () {
  if ('opening' == this.readyState || 'open' == this.readyState) {
    this.readyState = 'closing';

    var self = this;

    function close() {
      self.onClose('forced close');
      debug('socket closing - telling transport to close');
      self.transport.close();
    }

    function cleanupAndClose() {
      self.removeListener('upgrade', cleanupAndClose);
      self.removeListener('upgradeError', cleanupAndClose);
      close();
    }

    function waitForUpgrade() {
      // wait for upgrade to finish since we can't send packets while pausing a transport
      self.once('upgrade', cleanupAndClose);
      self.once('upgradeError', cleanupAndClose);
    }

    if (this.writeBuffer.length) {
      this.once('drain', function() {
        if (this.upgrading) {
          waitForUpgrade();
        } else {
          close();
        }
      });
    } else if (this.upgrading) {
      waitForUpgrade();
    } else {
      close();
    }
  }

  return this;
};

/**
 * Called upon transport error
 *
 * @api private
 */

Socket.prototype.onError = function (err) {
  debug('socket error %j', err);
  Socket.priorWebsocketSuccess = false;
  this.emit('error', err);
  this.onClose('transport error', err);
};

/**
 * Called upon transport close.
 *
 * @api private
 */

Socket.prototype.onClose = function (reason, desc) {
  if ('opening' == this.readyState || 'open' == this.readyState || 'closing' == this.readyState) {
    debug('socket close with reason: "%s"', reason);
    var self = this;

    // clear timers
    clearTimeout(this.pingIntervalTimer);
    clearTimeout(this.pingTimeoutTimer);

    // clean buffers in next tick, so developers can still
    // grab the buffers on `close` event
    setTimeout(function() {
      self.writeBuffer = [];
      self.callbackBuffer = [];
      self.prevBufferLen = 0;
    }, 0);

    // stop event from firing again for transport
    this.transport.removeAllListeners('close');

    // ensure transport won't stay open
    this.transport.close();

    // ignore further transport communication
    this.transport.removeAllListeners();

    // set ready state
    this.readyState = 'closed';

    // clear session id
    this.id = null;

    // emit close event
    this.emit('close', reason, desc);
  }
};

/**
 * Filters upgrades, returning only those matching client transports.
 *
 * @param {Array} server upgrades
 * @api private
 *
 */

Socket.prototype.filterUpgrades = function (upgrades) {
  var filteredUpgrades = [];
  for (var i = 0, j = upgrades.length; i<j; i++) {
    if (~index(this.transports, upgrades[i])) filteredUpgrades.push(upgrades[i]);
  }
  return filteredUpgrades;
};

}).call(this,typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"./transport":4,"./transports":5,"component-emitter":12,"debug":14,"engine.io-parser":17,"indexof":27,"parsejson":28,"parseqs":29,"parseuri":30}],4:[function(_dereq_,module,exports){
/**
 * Module dependencies.
 */

var parser = _dereq_('engine.io-parser');
var Emitter = _dereq_('component-emitter');

/**
 * Module exports.
 */

module.exports = Transport;

/**
 * Transport abstract constructor.
 *
 * @param {Object} options.
 * @api private
 */

function Transport (opts) {
  this.path = opts.path;
  this.hostname = opts.hostname;
  this.port = opts.port;
  this.secure = opts.secure;
  this.query = opts.query;
  this.timestampParam = opts.timestampParam;
  this.timestampRequests = opts.timestampRequests;
  this.readyState = '';
  this.agent = opts.agent || false;
  this.socket = opts.socket;
  this.enablesXDR = opts.enablesXDR;

  // SSL options for Node.js client
  this.pfx = opts.pfx;
  this.key = opts.key;
  this.passphrase = opts.passphrase;
  this.cert = opts.cert;
  this.ca = opts.ca;
  this.ciphers = opts.ciphers;
  this.rejectUnauthorized = opts.rejectUnauthorized;
}

/**
 * Mix in `Emitter`.
 */

Emitter(Transport.prototype);

/**
 * A counter used to prevent collisions in the timestamps used
 * for cache busting.
 */

Transport.timestamps = 0;

/**
 * Emits an error.
 *
 * @param {String} str
 * @return {Transport} for chaining
 * @api public
 */

Transport.prototype.onError = function (msg, desc) {
  var err = new Error(msg);
  err.type = 'TransportError';
  err.description = desc;
  this.emit('error', err);
  return this;
};

/**
 * Opens the transport.
 *
 * @api public
 */

Transport.prototype.open = function () {
  if ('closed' == this.readyState || '' == this.readyState) {
    this.readyState = 'opening';
    this.doOpen();
  }

  return this;
};

/**
 * Closes the transport.
 *
 * @api private
 */

Transport.prototype.close = function () {
  if ('opening' == this.readyState || 'open' == this.readyState) {
    this.doClose();
    this.onClose();
  }

  return this;
};

/**
 * Sends multiple packets.
 *
 * @param {Array} packets
 * @api private
 */

Transport.prototype.send = function(packets){
  if ('open' == this.readyState) {
    this.write(packets);
  } else {
    throw new Error('Transport not open');
  }
};

/**
 * Called upon open
 *
 * @api private
 */

Transport.prototype.onOpen = function () {
  this.readyState = 'open';
  this.writable = true;
  this.emit('open');
};

/**
 * Called with data.
 *
 * @param {String} data
 * @api private
 */

Transport.prototype.onData = function(data){
  var packet = parser.decodePacket(data, this.socket.binaryType);
  this.onPacket(packet);
};

/**
 * Called with a decoded packet.
 */

Transport.prototype.onPacket = function (packet) {
  this.emit('packet', packet);
};

/**
 * Called upon close.
 *
 * @api private
 */

Transport.prototype.onClose = function () {
  this.readyState = 'closed';
  this.emit('close');
};

},{"component-emitter":12,"engine.io-parser":17}],5:[function(_dereq_,module,exports){
(function (global){
/**
 * Module dependencies
 */

var XMLHttpRequest = _dereq_('xmlhttprequest');
var XHR = _dereq_('./polling-xhr');
var JSONP = _dereq_('./polling-jsonp');
var websocket = _dereq_('./websocket');

/**
 * Export transports.
 */

exports.polling = polling;
exports.websocket = websocket;

/**
 * Polling transport polymorphic constructor.
 * Decides on xhr vs jsonp based on feature detection.
 *
 * @api private
 */

function polling(opts){
  var xhr;
  var xd = false;
  var xs = false;
  var jsonp = false !== opts.jsonp;

  if (global.location) {
    var isSSL = 'https:' == location.protocol;
    var port = location.port;

    // some user agents have empty `location.port`
    if (!port) {
      port = isSSL ? 443 : 80;
    }

    xd = opts.hostname != location.hostname || port != opts.port;
    xs = opts.secure != isSSL;
  }

  opts.xdomain = xd;
  opts.xscheme = xs;
  xhr = new XMLHttpRequest(opts);

  if ('open' in xhr && !opts.forceJSONP) {
    return new XHR(opts);
  } else {
    if (!jsonp) throw new Error('JSONP disabled');
    return new JSONP(opts);
  }
}

}).call(this,typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"./polling-jsonp":6,"./polling-xhr":7,"./websocket":9,"xmlhttprequest":10}],6:[function(_dereq_,module,exports){
(function (global){

/**
 * Module requirements.
 */

var Polling = _dereq_('./polling');
var inherit = _dereq_('component-inherit');

/**
 * Module exports.
 */

module.exports = JSONPPolling;

/**
 * Cached regular expressions.
 */

var rNewline = /\n/g;
var rEscapedNewline = /\\n/g;

/**
 * Global JSONP callbacks.
 */

var callbacks;

/**
 * Callbacks count.
 */

var index = 0;

/**
 * Noop.
 */

function empty () { }

/**
 * JSONP Polling constructor.
 *
 * @param {Object} opts.
 * @api public
 */

function JSONPPolling (opts) {
  Polling.call(this, opts);

  this.query = this.query || {};

  // define global callbacks array if not present
  // we do this here (lazily) to avoid unneeded global pollution
  if (!callbacks) {
    // we need to consider multiple engines in the same page
    if (!global.___eio) global.___eio = [];
    callbacks = global.___eio;
  }

  // callback identifier
  this.index = callbacks.length;

  // add callback to jsonp global
  var self = this;
  callbacks.push(function (msg) {
    self.onData(msg);
  });

  // append to query string
  this.query.j = this.index;

  // prevent spurious errors from being emitted when the window is unloaded
  if (global.document && global.addEventListener) {
    global.addEventListener('beforeunload', function () {
      if (self.script) self.script.onerror = empty;
    }, false);
  }
}

/**
 * Inherits from Polling.
 */

inherit(JSONPPolling, Polling);

/*
 * JSONP only supports binary as base64 encoded strings
 */

JSONPPolling.prototype.supportsBinary = false;

/**
 * Closes the socket.
 *
 * @api private
 */

JSONPPolling.prototype.doClose = function () {
  if (this.script) {
    this.script.parentNode.removeChild(this.script);
    this.script = null;
  }

  if (this.form) {
    this.form.parentNode.removeChild(this.form);
    this.form = null;
    this.iframe = null;
  }

  Polling.prototype.doClose.call(this);
};

/**
 * Starts a poll cycle.
 *
 * @api private
 */

JSONPPolling.prototype.doPoll = function () {
  var self = this;
  var script = document.createElement('script');

  if (this.script) {
    this.script.parentNode.removeChild(this.script);
    this.script = null;
  }

  script.async = true;
  script.src = this.uri();
  script.onerror = function(e){
    self.onError('jsonp poll error',e);
  };

  var insertAt = document.getElementsByTagName('script')[0];
  insertAt.parentNode.insertBefore(script, insertAt);
  this.script = script;

  var isUAgecko = 'undefined' != typeof navigator && /gecko/i.test(navigator.userAgent);
  
  if (isUAgecko) {
    setTimeout(function () {
      var iframe = document.createElement('iframe');
      document.body.appendChild(iframe);
      document.body.removeChild(iframe);
    }, 100);
  }
};

/**
 * Writes with a hidden iframe.
 *
 * @param {String} data to send
 * @param {Function} called upon flush.
 * @api private
 */

JSONPPolling.prototype.doWrite = function (data, fn) {
  var self = this;

  if (!this.form) {
    var form = document.createElement('form');
    var area = document.createElement('textarea');
    var id = this.iframeId = 'eio_iframe_' + this.index;
    var iframe;

    form.className = 'socketio';
    form.style.position = 'absolute';
    form.style.top = '-1000px';
    form.style.left = '-1000px';
    form.target = id;
    form.method = 'POST';
    form.setAttribute('accept-charset', 'utf-8');
    area.name = 'd';
    form.appendChild(area);
    document.body.appendChild(form);

    this.form = form;
    this.area = area;
  }

  this.form.action = this.uri();

  function complete () {
    initIframe();
    fn();
  }

  function initIframe () {
    if (self.iframe) {
      try {
        self.form.removeChild(self.iframe);
      } catch (e) {
        self.onError('jsonp polling iframe removal error', e);
      }
    }

    try {
      // ie6 dynamic iframes with target="" support (thanks Chris Lambacher)
      var html = '<iframe src="javascript:0" name="'+ self.iframeId +'">';
      iframe = document.createElement(html);
    } catch (e) {
      iframe = document.createElement('iframe');
      iframe.name = self.iframeId;
      iframe.src = 'javascript:0';
    }

    iframe.id = self.iframeId;

    self.form.appendChild(iframe);
    self.iframe = iframe;
  }

  initIframe();

  // escape \n to prevent it from being converted into \r\n by some UAs
  // double escaping is required for escaped new lines because unescaping of new lines can be done safely on server-side
  data = data.replace(rEscapedNewline, '\\\n');
  this.area.value = data.replace(rNewline, '\\n');

  try {
    this.form.submit();
  } catch(e) {}

  if (this.iframe.attachEvent) {
    this.iframe.onreadystatechange = function(){
      if (self.iframe.readyState == 'complete') {
        complete();
      }
    };
  } else {
    this.iframe.onload = complete;
  }
};

}).call(this,typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"./polling":8,"component-inherit":13}],7:[function(_dereq_,module,exports){
(function (global){
/**
 * Module requirements.
 */

var XMLHttpRequest = _dereq_('xmlhttprequest');
var Polling = _dereq_('./polling');
var Emitter = _dereq_('component-emitter');
var inherit = _dereq_('component-inherit');
var debug = _dereq_('debug')('engine.io-client:polling-xhr');

/**
 * Module exports.
 */

module.exports = XHR;
module.exports.Request = Request;

/**
 * Empty function
 */

function empty(){}

/**
 * XHR Polling constructor.
 *
 * @param {Object} opts
 * @api public
 */

function XHR(opts){
  Polling.call(this, opts);

  if (global.location) {
    var isSSL = 'https:' == location.protocol;
    var port = location.port;

    // some user agents have empty `location.port`
    if (!port) {
      port = isSSL ? 443 : 80;
    }

    this.xd = opts.hostname != global.location.hostname ||
      port != opts.port;
    this.xs = opts.secure != isSSL;
  }
}

/**
 * Inherits from Polling.
 */

inherit(XHR, Polling);

/**
 * XHR supports binary
 */

XHR.prototype.supportsBinary = true;

/**
 * Creates a request.
 *
 * @param {String} method
 * @api private
 */

XHR.prototype.request = function(opts){
  opts = opts || {};
  opts.uri = this.uri();
  opts.xd = this.xd;
  opts.xs = this.xs;
  opts.agent = this.agent || false;
  opts.supportsBinary = this.supportsBinary;
  opts.enablesXDR = this.enablesXDR;

  // SSL options for Node.js client
  opts.pfx = this.pfx;
  opts.key = this.key;
  opts.passphrase = this.passphrase;
  opts.cert = this.cert;
  opts.ca = this.ca;
  opts.ciphers = this.ciphers;
  opts.rejectUnauthorized = this.rejectUnauthorized;

  return new Request(opts);
};

/**
 * Sends data.
 *
 * @param {String} data to send.
 * @param {Function} called upon flush.
 * @api private
 */

XHR.prototype.doWrite = function(data, fn){
  var isBinary = typeof data !== 'string' && data !== undefined;
  var req = this.request({ method: 'POST', data: data, isBinary: isBinary });
  var self = this;
  req.on('success', fn);
  req.on('error', function(err){
    self.onError('xhr post error', err);
  });
  this.sendXhr = req;
};

/**
 * Starts a poll cycle.
 *
 * @api private
 */

XHR.prototype.doPoll = function(){
  debug('xhr poll');
  var req = this.request();
  var self = this;
  req.on('data', function(data){
    self.onData(data);
  });
  req.on('error', function(err){
    self.onError('xhr poll error', err);
  });
  this.pollXhr = req;
};

/**
 * Request constructor
 *
 * @param {Object} options
 * @api public
 */

function Request(opts){
  this.method = opts.method || 'GET';
  this.uri = opts.uri;
  this.xd = !!opts.xd;
  this.xs = !!opts.xs;
  this.async = false !== opts.async;
  this.data = undefined != opts.data ? opts.data : null;
  this.agent = opts.agent;
  this.isBinary = opts.isBinary;
  this.supportsBinary = opts.supportsBinary;
  this.enablesXDR = opts.enablesXDR;

  // SSL options for Node.js client
  this.pfx = opts.pfx;
  this.key = opts.key;
  this.passphrase = opts.passphrase;
  this.cert = opts.cert;
  this.ca = opts.ca;
  this.ciphers = opts.ciphers;
  this.rejectUnauthorized = opts.rejectUnauthorized;

  this.create();
}

/**
 * Mix in `Emitter`.
 */

Emitter(Request.prototype);

/**
 * Creates the XHR object and sends the request.
 *
 * @api private
 */

Request.prototype.create = function(){
  var opts = { agent: this.agent, xdomain: this.xd, xscheme: this.xs, enablesXDR: this.enablesXDR };

  // SSL options for Node.js client
  opts.pfx = this.pfx;
  opts.key = this.key;
  opts.passphrase = this.passphrase;
  opts.cert = this.cert;
  opts.ca = this.ca;
  opts.ciphers = this.ciphers;
  opts.rejectUnauthorized = this.rejectUnauthorized;

  var xhr = this.xhr = new XMLHttpRequest(opts);
  var self = this;

  try {
    debug('xhr open %s: %s', this.method, this.uri);
    xhr.open(this.method, this.uri, this.async);
    if (this.supportsBinary) {
      // This has to be done after open because Firefox is stupid
      // http://stackoverflow.com/questions/13216903/get-binary-data-with-xmlhttprequest-in-a-firefox-extension
      xhr.responseType = 'arraybuffer';
    }

    if ('POST' == this.method) {
      try {
        if (this.isBinary) {
          xhr.setRequestHeader('Content-type', 'application/octet-stream');
        } else {
          xhr.setRequestHeader('Content-type', 'text/plain;charset=UTF-8');
        }
      } catch (e) {}
    }

    // ie6 check
    if ('withCredentials' in xhr) {
      xhr.withCredentials = true;
    }

    if (this.hasXDR()) {
      xhr.onload = function(){
        self.onLoad();
      };
      xhr.onerror = function(){
        self.onError(xhr.responseText);
      };
    } else {
      xhr.onreadystatechange = function(){
        if (4 != xhr.readyState) return;
        if (200 == xhr.status || 1223 == xhr.status) {
          self.onLoad();
        } else {
          // make sure the `error` event handler that's user-set
          // does not throw in the same tick and gets caught here
          setTimeout(function(){
            self.onError(xhr.status);
          }, 0);
        }
      };
    }

    debug('xhr data %s', this.data);
    xhr.send(this.data);
  } catch (e) {
    // Need to defer since .create() is called directly fhrom the constructor
    // and thus the 'error' event can only be only bound *after* this exception
    // occurs.  Therefore, also, we cannot throw here at all.
    setTimeout(function() {
      self.onError(e);
    }, 0);
    return;
  }

  if (global.document) {
    this.index = Request.requestsCount++;
    Request.requests[this.index] = this;
  }
};

/**
 * Called upon successful response.
 *
 * @api private
 */

Request.prototype.onSuccess = function(){
  this.emit('success');
  this.cleanup();
};

/**
 * Called if we have data.
 *
 * @api private
 */

Request.prototype.onData = function(data){
  this.emit('data', data);
  this.onSuccess();
};

/**
 * Called upon error.
 *
 * @api private
 */

Request.prototype.onError = function(err){
  this.emit('error', err);
  this.cleanup(true);
};

/**
 * Cleans up house.
 *
 * @api private
 */

Request.prototype.cleanup = function(fromError){
  if ('undefined' == typeof this.xhr || null === this.xhr) {
    return;
  }
  // xmlhttprequest
  if (this.hasXDR()) {
    this.xhr.onload = this.xhr.onerror = empty;
  } else {
    this.xhr.onreadystatechange = empty;
  }

  if (fromError) {
    try {
      this.xhr.abort();
    } catch(e) {}
  }

  if (global.document) {
    delete Request.requests[this.index];
  }

  this.xhr = null;
};

/**
 * Called upon load.
 *
 * @api private
 */

Request.prototype.onLoad = function(){
  var data;
  try {
    var contentType;
    try {
      contentType = this.xhr.getResponseHeader('Content-Type').split(';')[0];
    } catch (e) {}
    if (contentType === 'application/octet-stream') {
      data = this.xhr.response;
    } else {
      if (!this.supportsBinary) {
        data = this.xhr.responseText;
      } else {
        data = 'ok';
      }
    }
  } catch (e) {
    this.onError(e);
  }
  if (null != data) {
    this.onData(data);
  }
};

/**
 * Check if it has XDomainRequest.
 *
 * @api private
 */

Request.prototype.hasXDR = function(){
  return 'undefined' !== typeof global.XDomainRequest && !this.xs && this.enablesXDR;
};

/**
 * Aborts the request.
 *
 * @api public
 */

Request.prototype.abort = function(){
  this.cleanup();
};

/**
 * Aborts pending requests when unloading the window. This is needed to prevent
 * memory leaks (e.g. when using IE) and to ensure that no spurious error is
 * emitted.
 */

if (global.document) {
  Request.requestsCount = 0;
  Request.requests = {};
  if (global.attachEvent) {
    global.attachEvent('onunload', unloadHandler);
  } else if (global.addEventListener) {
    global.addEventListener('beforeunload', unloadHandler, false);
  }
}

function unloadHandler() {
  for (var i in Request.requests) {
    if (Request.requests.hasOwnProperty(i)) {
      Request.requests[i].abort();
    }
  }
}

}).call(this,typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"./polling":8,"component-emitter":12,"component-inherit":13,"debug":14,"xmlhttprequest":10}],8:[function(_dereq_,module,exports){
/**
 * Module dependencies.
 */

var Transport = _dereq_('../transport');
var parseqs = _dereq_('parseqs');
var parser = _dereq_('engine.io-parser');
var inherit = _dereq_('component-inherit');
var debug = _dereq_('debug')('engine.io-client:polling');

/**
 * Module exports.
 */

module.exports = Polling;

/**
 * Is XHR2 supported?
 */

var hasXHR2 = (function() {
  var XMLHttpRequest = _dereq_('xmlhttprequest');
  var xhr = new XMLHttpRequest({ xdomain: false });
  return null != xhr.responseType;
})();

/**
 * Polling interface.
 *
 * @param {Object} opts
 * @api private
 */

function Polling(opts){
  var forceBase64 = (opts && opts.forceBase64);
  if (!hasXHR2 || forceBase64) {
    this.supportsBinary = false;
  }
  Transport.call(this, opts);
}

/**
 * Inherits from Transport.
 */

inherit(Polling, Transport);

/**
 * Transport name.
 */

Polling.prototype.name = 'polling';

/**
 * Opens the socket (triggers polling). We write a PING message to determine
 * when the transport is open.
 *
 * @api private
 */

Polling.prototype.doOpen = function(){
  this.poll();
};

/**
 * Pauses polling.
 *
 * @param {Function} callback upon buffers are flushed and transport is paused
 * @api private
 */

Polling.prototype.pause = function(onPause){
  var pending = 0;
  var self = this;

  this.readyState = 'pausing';

  function pause(){
    debug('paused');
    self.readyState = 'paused';
    onPause();
  }

  if (this.polling || !this.writable) {
    var total = 0;

    if (this.polling) {
      debug('we are currently polling - waiting to pause');
      total++;
      this.once('pollComplete', function(){
        debug('pre-pause polling complete');
        --total || pause();
      });
    }

    if (!this.writable) {
      debug('we are currently writing - waiting to pause');
      total++;
      this.once('drain', function(){
        debug('pre-pause writing complete');
        --total || pause();
      });
    }
  } else {
    pause();
  }
};

/**
 * Starts polling cycle.
 *
 * @api public
 */

Polling.prototype.poll = function(){
  debug('polling');
  this.polling = true;
  this.doPoll();
  this.emit('poll');
};

/**
 * Overloads onData to detect payloads.
 *
 * @api private
 */

Polling.prototype.onData = function(data){
  var self = this;
  debug('polling got data %s', data);
  var callback = function(packet, index, total) {
    // if its the first message we consider the transport open
    if ('opening' == self.readyState) {
      self.onOpen();
    }

    // if its a close packet, we close the ongoing requests
    if ('close' == packet.type) {
      self.onClose();
      return false;
    }

    // otherwise bypass onData and handle the message
    self.onPacket(packet);
  };

  // decode payload
  parser.decodePayload(data, this.socket.binaryType, callback);

  // if an event did not trigger closing
  if ('closed' != this.readyState) {
    // if we got data we're not polling
    this.polling = false;
    this.emit('pollComplete');

    if ('open' == this.readyState) {
      this.poll();
    } else {
      debug('ignoring poll - transport state "%s"', this.readyState);
    }
  }
};

/**
 * For polling, send a close packet.
 *
 * @api private
 */

Polling.prototype.doClose = function(){
  var self = this;

  function close(){
    debug('writing close packet');
    self.write([{ type: 'close' }]);
  }

  if ('open' == this.readyState) {
    debug('transport open - closing');
    close();
  } else {
    // in case we're trying to close while
    // handshaking is in progress (GH-164)
    debug('transport not open - deferring close');
    this.once('open', close);
  }
};

/**
 * Writes a packets payload.
 *
 * @param {Array} data packets
 * @param {Function} drain callback
 * @api private
 */

Polling.prototype.write = function(packets){
  var self = this;
  this.writable = false;
  var callbackfn = function() {
    self.writable = true;
    self.emit('drain');
  };

  var self = this;
  parser.encodePayload(packets, this.supportsBinary, function(data) {
    self.doWrite(data, callbackfn);
  });
};

/**
 * Generates uri for connection.
 *
 * @api private
 */

Polling.prototype.uri = function(){
  var query = this.query || {};
  var schema = this.secure ? 'https' : 'http';
  var port = '';

  // cache busting is forced
  if (false !== this.timestampRequests) {
    query[this.timestampParam] = +new Date + '-' + Transport.timestamps++;
  }

  if (!this.supportsBinary && !query.sid) {
    query.b64 = 1;
  }

  query = parseqs.encode(query);

  // avoid port if default for schema
  if (this.port && (('https' == schema && this.port != 443) ||
     ('http' == schema && this.port != 80))) {
    port = ':' + this.port;
  }

  // prepend ? to query
  if (query.length) {
    query = '?' + query;
  }

  return schema + '://' + this.hostname + port + this.path + query;
};

},{"../transport":4,"component-inherit":13,"debug":14,"engine.io-parser":17,"parseqs":29,"xmlhttprequest":10}],9:[function(_dereq_,module,exports){
/**
 * Module dependencies.
 */

var Transport = _dereq_('../transport');
var parser = _dereq_('engine.io-parser');
var parseqs = _dereq_('parseqs');
var inherit = _dereq_('component-inherit');
var debug = _dereq_('debug')('engine.io-client:websocket');

/**
 * `ws` exposes a WebSocket-compatible interface in
 * Node, or the `WebSocket` or `MozWebSocket` globals
 * in the browser.
 */

var WebSocket = _dereq_('ws');

/**
 * Module exports.
 */

module.exports = WS;

/**
 * WebSocket transport constructor.
 *
 * @api {Object} connection options
 * @api public
 */

function WS(opts){
  var forceBase64 = (opts && opts.forceBase64);
  if (forceBase64) {
    this.supportsBinary = false;
  }
  Transport.call(this, opts);
}

/**
 * Inherits from Transport.
 */

inherit(WS, Transport);

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

WS.prototype.name = 'websocket';

/*
 * WebSockets support binary
 */

WS.prototype.supportsBinary = true;

/**
 * Opens socket.
 *
 * @api private
 */

WS.prototype.doOpen = function(){
  if (!this.check()) {
    // let probe timeout
    return;
  }

  var self = this;
  var uri = this.uri();
  var protocols = void(0);
  var opts = { agent: this.agent };

  // SSL options for Node.js client
  opts.pfx = this.pfx;
  opts.key = this.key;
  opts.passphrase = this.passphrase;
  opts.cert = this.cert;
  opts.ca = this.ca;
  opts.ciphers = this.ciphers;
  opts.rejectUnauthorized = this.rejectUnauthorized;

  this.ws = new WebSocket(uri, protocols, opts);

  if (this.ws.binaryType === undefined) {
    this.supportsBinary = false;
  }

  this.ws.binaryType = 'arraybuffer';
  this.addEventListeners();
};

/**
 * Adds event listeners to the socket
 *
 * @api private
 */

WS.prototype.addEventListeners = function(){
  var self = this;

  this.ws.onopen = function(){
    self.onOpen();
  };
  this.ws.onclose = function(){
    self.onClose();
  };
  this.ws.onmessage = function(ev){
    self.onData(ev.data);
  };
  this.ws.onerror = function(e){
    self.onError('websocket error', e);
  };
};

/**
 * Override `onData` to use a timer on iOS.
 * See: https://gist.github.com/mloughran/2052006
 *
 * @api private
 */

if ('undefined' != typeof navigator
  && /iPad|iPhone|iPod/i.test(navigator.userAgent)) {
  WS.prototype.onData = function(data){
    var self = this;
    setTimeout(function(){
      Transport.prototype.onData.call(self, data);
    }, 0);
  };
}

/**
 * Writes data to socket.
 *
 * @param {Array} array of packets.
 * @api private
 */

WS.prototype.write = function(packets){
  var self = this;
  this.writable = false;
  // encodePacket efficient as it uses WS framing
  // no need for encodePayload
  for (var i = 0, l = packets.length; i < l; i++) {
    parser.encodePacket(packets[i], this.supportsBinary, function(data) {
      //Sometimes the websocket has already been closed but the browser didn't
      //have a chance of informing us about it yet, in that case send will
      //throw an error
      try {
        self.ws.send(data);
      } catch (e){
        debug('websocket closed before onclose event');
      }
    });
  }

  function ondrain() {
    self.writable = true;
    self.emit('drain');
  }
  // fake drain
  // defer to next tick to allow Socket to clear writeBuffer
  setTimeout(ondrain, 0);
};

/**
 * Called upon close
 *
 * @api private
 */

WS.prototype.onClose = function(){
  Transport.prototype.onClose.call(this);
};

/**
 * Closes socket.
 *
 * @api private
 */

WS.prototype.doClose = function(){
  if (typeof this.ws !== 'undefined') {
    this.ws.close();
  }
};

/**
 * Generates uri for connection.
 *
 * @api private
 */

WS.prototype.uri = function(){
  var query = this.query || {};
  var schema = this.secure ? 'wss' : 'ws';
  var port = '';

  // avoid port if default for schema
  if (this.port && (('wss' == schema && this.port != 443)
    || ('ws' == schema && this.port != 80))) {
    port = ':' + this.port;
  }

  // append timestamp to URI
  if (this.timestampRequests) {
    query[this.timestampParam] = +new Date;
  }

  // communicate binary support capabilities
  if (!this.supportsBinary) {
    query.b64 = 1;
  }

  query = parseqs.encode(query);

  // prepend ? to query
  if (query.length) {
    query = '?' + query;
  }

  return schema + '://' + this.hostname + port + this.path + query;
};

/**
 * Feature detection for WebSocket.
 *
 * @return {Boolean} whether this transport is available.
 * @api public
 */

WS.prototype.check = function(){
  return !!WebSocket && !('__initialize' in WebSocket && this.name === WS.prototype.name);
};

},{"../transport":4,"component-inherit":13,"debug":14,"engine.io-parser":17,"parseqs":29,"ws":31}],10:[function(_dereq_,module,exports){
// browser shim for xmlhttprequest module
var hasCORS = _dereq_('has-cors');

module.exports = function(opts) {
  var xdomain = opts.xdomain;

  // scheme must be same when usign XDomainRequest
  // http://blogs.msdn.com/b/ieinternals/archive/2010/05/13/xdomainrequest-restrictions-limitations-and-workarounds.aspx
  var xscheme = opts.xscheme;

  // XDomainRequest has a flow of not sending cookie, therefore it should be disabled as a default.
  // https://github.com/Automattic/engine.io-client/pull/217
  var enablesXDR = opts.enablesXDR;

  // XMLHttpRequest can be disabled on IE
  try {
    if ('undefined' != typeof XMLHttpRequest && (!xdomain || hasCORS)) {
      return new XMLHttpRequest();
    }
  } catch (e) { }

  // Use XDomainRequest for IE8 if enablesXDR is true
  // because loading bar keeps flashing when using jsonp-polling
  // https://github.com/yujiosaka/socke.io-ie8-loading-example
  try {
    if ('undefined' != typeof XDomainRequest && !xscheme && enablesXDR) {
      return new XDomainRequest();
    }
  } catch (e) { }

  if (!xdomain) {
    try {
      return new ActiveXObject('Microsoft.XMLHTTP');
    } catch(e) { }
  }
}

},{"has-cors":25}],11:[function(_dereq_,module,exports){
(function (global){
/**
 * Create a blob builder even when vendor prefixes exist
 */

var BlobBuilder = global.BlobBuilder
  || global.WebKitBlobBuilder
  || global.MSBlobBuilder
  || global.MozBlobBuilder;

/**
 * Check if Blob constructor is supported
 */

var blobSupported = (function() {
  try {
    var b = new Blob(['hi']);
    return b.size == 2;
  } catch(e) {
    return false;
  }
})();

/**
 * Check if BlobBuilder is supported
 */

var blobBuilderSupported = BlobBuilder
  && BlobBuilder.prototype.append
  && BlobBuilder.prototype.getBlob;

function BlobBuilderConstructor(ary, options) {
  options = options || {};

  var bb = new BlobBuilder();
  for (var i = 0; i < ary.length; i++) {
    bb.append(ary[i]);
  }
  return (options.type) ? bb.getBlob(options.type) : bb.getBlob();
};

module.exports = (function() {
  if (blobSupported) {
    return global.Blob;
  } else if (blobBuilderSupported) {
    return BlobBuilderConstructor;
  } else {
    return undefined;
  }
})();

}).call(this,typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{}],12:[function(_dereq_,module,exports){

/**
 * Expose `Emitter`.
 */

module.exports = Emitter;

/**
 * Initialize a new `Emitter`.
 *
 * @api public
 */

function Emitter(obj) {
  if (obj) return mixin(obj);
};

/**
 * Mixin the emitter properties.
 *
 * @param {Object} obj
 * @return {Object}
 * @api private
 */

function mixin(obj) {
  for (var key in Emitter.prototype) {
    obj[key] = Emitter.prototype[key];
  }
  return obj;
}

/**
 * Listen on the given `event` with `fn`.
 *
 * @param {String} event
 * @param {Function} fn
 * @return {Emitter}
 * @api public
 */

Emitter.prototype.on =
Emitter.prototype.addEventListener = function(event, fn){
  this._callbacks = this._callbacks || {};
  (this._callbacks[event] = this._callbacks[event] || [])
    .push(fn);
  return this;
};

/**
 * Adds an `event` listener that will be invoked a single
 * time then automatically removed.
 *
 * @param {String} event
 * @param {Function} fn
 * @return {Emitter}
 * @api public
 */

Emitter.prototype.once = function(event, fn){
  var self = this;
  this._callbacks = this._callbacks || {};

  function on() {
    self.off(event, on);
    fn.apply(this, arguments);
  }

  on.fn = fn;
  this.on(event, on);
  return this;
};

/**
 * Remove the given callback for `event` or all
 * registered callbacks.
 *
 * @param {String} event
 * @param {Function} fn
 * @return {Emitter}
 * @api public
 */

Emitter.prototype.off =
Emitter.prototype.removeListener =
Emitter.prototype.removeAllListeners =
Emitter.prototype.removeEventListener = function(event, fn){
  this._callbacks = this._callbacks || {};

  // all
  if (0 == arguments.length) {
    this._callbacks = {};
    return this;
  }

  // specific event
  var callbacks = this._callbacks[event];
  if (!callbacks) return this;

  // remove all handlers
  if (1 == arguments.length) {
    delete this._callbacks[event];
    return this;
  }

  // remove specific handler
  var cb;
  for (var i = 0; i < callbacks.length; i++) {
    cb = callbacks[i];
    if (cb === fn || cb.fn === fn) {
      callbacks.splice(i, 1);
      break;
    }
  }
  return this;
};

/**
 * Emit `event` with the given args.
 *
 * @param {String} event
 * @param {Mixed} ...
 * @return {Emitter}
 */

Emitter.prototype.emit = function(event){
  this._callbacks = this._callbacks || {};
  var args = [].slice.call(arguments, 1)
    , callbacks = this._callbacks[event];

  if (callbacks) {
    callbacks = callbacks.slice(0);
    for (var i = 0, len = callbacks.length; i < len; ++i) {
      callbacks[i].apply(this, args);
    }
  }

  return this;
};

/**
 * Return array of callbacks for `event`.
 *
 * @param {String} event
 * @return {Array}
 * @api public
 */

Emitter.prototype.listeners = function(event){
  this._callbacks = this._callbacks || {};
  return this._callbacks[event] || [];
};

/**
 * Check if this emitter has `event` handlers.
 *
 * @param {String} event
 * @return {Boolean}
 * @api public
 */

Emitter.prototype.hasListeners = function(event){
  return !! this.listeners(event).length;
};

},{}],13:[function(_dereq_,module,exports){

module.exports = function(a, b){
  var fn = function(){};
  fn.prototype = b.prototype;
  a.prototype = new fn;
  a.prototype.constructor = a;
};
},{}],14:[function(_dereq_,module,exports){

/**
 * This is the web browser implementation of `debug()`.
 *
 * Expose `debug()` as the module.
 */

exports = module.exports = _dereq_('./debug');
exports.log = log;
exports.formatArgs = formatArgs;
exports.save = save;
exports.load = load;
exports.useColors = useColors;

/**
 * Colors.
 */

exports.colors = [
  'lightseagreen',
  'forestgreen',
  'goldenrod',
  'dodgerblue',
  'darkorchid',
  'crimson'
];

/**
 * Currently only WebKit-based Web Inspectors, Firefox >= v31,
 * and the Firebug extension (any Firefox version) are known
 * to support "%c" CSS customizations.
 *
 * TODO: add a `localStorage` variable to explicitly enable/disable colors
 */

function useColors() {
  // is webkit? http://stackoverflow.com/a/16459606/376773
  return ('WebkitAppearance' in document.documentElement.style) ||
    // is firebug? http://stackoverflow.com/a/398120/376773
    (window.console && (console.firebug || (console.exception && console.table))) ||
    // is firefox >= v31?
    // https://developer.mozilla.org/en-US/docs/Tools/Web_Console#Styling_messages
    (navigator.userAgent.toLowerCase().match(/firefox\/(\d+)/) && parseInt(RegExp.$1, 10) >= 31);
}

/**
 * Map %j to `JSON.stringify()`, since no Web Inspectors do that by default.
 */

exports.formatters.j = function(v) {
  return JSON.stringify(v);
};


/**
 * Colorize log arguments if enabled.
 *
 * @api public
 */

function formatArgs() {
  var args = arguments;
  var useColors = this.useColors;

  args[0] = (useColors ? '%c' : '')
    + this.namespace
    + (useColors ? ' %c' : ' ')
    + args[0]
    + (useColors ? '%c ' : ' ')
    + '+' + exports.humanize(this.diff);

  if (!useColors) return args;

  var c = 'color: ' + this.color;
  args = [args[0], c, 'color: inherit'].concat(Array.prototype.slice.call(args, 1));

  // the final "%c" is somewhat tricky, because there could be other
  // arguments passed either before or after the %c, so we need to
  // figure out the correct index to insert the CSS into
  var index = 0;
  var lastC = 0;
  args[0].replace(/%[a-z%]/g, function(match) {
    if ('%' === match) return;
    index++;
    if ('%c' === match) {
      // we only are interested in the *last* %c
      // (the user may have provided their own)
      lastC = index;
    }
  });

  args.splice(lastC, 0, c);
  return args;
}

/**
 * Invokes `console.log()` when available.
 * No-op when `console.log` is not a "function".
 *
 * @api public
 */

function log() {
  // This hackery is required for IE8,
  // where the `console.log` function doesn't have 'apply'
  return 'object' == typeof console
    && 'function' == typeof console.log
    && Function.prototype.apply.call(console.log, console, arguments);
}

/**
 * Save `namespaces`.
 *
 * @param {String} namespaces
 * @api private
 */

function save(namespaces) {
  try {
    if (null == namespaces) {
      localStorage.removeItem('debug');
    } else {
      localStorage.debug = namespaces;
    }
  } catch(e) {}
}

/**
 * Load `namespaces`.
 *
 * @return {String} returns the previously persisted debug modes
 * @api private
 */

function load() {
  var r;
  try {
    r = localStorage.debug;
  } catch(e) {}
  return r;
}

/**
 * Enable namespaces listed in `localStorage.debug` initially.
 */

exports.enable(load());

},{"./debug":15}],15:[function(_dereq_,module,exports){

/**
 * This is the common logic for both the Node.js and web browser
 * implementations of `debug()`.
 *
 * Expose `debug()` as the module.
 */

exports = module.exports = debug;
exports.coerce = coerce;
exports.disable = disable;
exports.enable = enable;
exports.enabled = enabled;
exports.humanize = _dereq_('ms');

/**
 * The currently active debug mode names, and names to skip.
 */

exports.names = [];
exports.skips = [];

/**
 * Map of special "%n" handling functions, for the debug "format" argument.
 *
 * Valid key names are a single, lowercased letter, i.e. "n".
 */

exports.formatters = {};

/**
 * Previously assigned color.
 */

var prevColor = 0;

/**
 * Previous log timestamp.
 */

var prevTime;

/**
 * Select a color.
 *
 * @return {Number}
 * @api private
 */

function selectColor() {
  return exports.colors[prevColor++ % exports.colors.length];
}

/**
 * Create a debugger with the given `namespace`.
 *
 * @param {String} namespace
 * @return {Function}
 * @api public
 */

function debug(namespace) {

  // define the `disabled` version
  function disabled() {
  }
  disabled.enabled = false;

  // define the `enabled` version
  function enabled() {

    var self = enabled;

    // set `diff` timestamp
    var curr = +new Date();
    var ms = curr - (prevTime || curr);
    self.diff = ms;
    self.prev = prevTime;
    self.curr = curr;
    prevTime = curr;

    // add the `color` if not set
    if (null == self.useColors) self.useColors = exports.useColors();
    if (null == self.color && self.useColors) self.color = selectColor();

    var args = Array.prototype.slice.call(arguments);

    args[0] = exports.coerce(args[0]);

    if ('string' !== typeof args[0]) {
      // anything else let's inspect with %o
      args = ['%o'].concat(args);
    }

    // apply any `formatters` transformations
    var index = 0;
    args[0] = args[0].replace(/%([a-z%])/g, function(match, format) {
      // if we encounter an escaped % then don't increase the array index
      if (match === '%') return match;
      index++;
      var formatter = exports.formatters[format];
      if ('function' === typeof formatter) {
        var val = args[index];
        match = formatter.call(self, val);

        // now we need to remove `args[index]` since it's inlined in the `format`
        args.splice(index, 1);
        index--;
      }
      return match;
    });

    if ('function' === typeof exports.formatArgs) {
      args = exports.formatArgs.apply(self, args);
    }
    var logFn = enabled.log || exports.log || console.log.bind(console);
    logFn.apply(self, args);
  }
  enabled.enabled = true;

  var fn = exports.enabled(namespace) ? enabled : disabled;

  fn.namespace = namespace;

  return fn;
}

/**
 * Enables a debug mode by namespaces. This can include modes
 * separated by a colon and wildcards.
 *
 * @param {String} namespaces
 * @api public
 */

function enable(namespaces) {
  exports.save(namespaces);

  var split = (namespaces || '').split(/[\s,]+/);
  var len = split.length;

  for (var i = 0; i < len; i++) {
    if (!split[i]) continue; // ignore empty strings
    namespaces = split[i].replace(/\*/g, '.*?');
    if (namespaces[0] === '-') {
      exports.skips.push(new RegExp('^' + namespaces.substr(1) + '$'));
    } else {
      exports.names.push(new RegExp('^' + namespaces + '$'));
    }
  }
}

/**
 * Disable debug output.
 *
 * @api public
 */

function disable() {
  exports.enable('');
}

/**
 * Returns true if the given mode name is enabled, false otherwise.
 *
 * @param {String} name
 * @return {Boolean}
 * @api public
 */

function enabled(name) {
  var i, len;
  for (i = 0, len = exports.skips.length; i < len; i++) {
    if (exports.skips[i].test(name)) {
      return false;
    }
  }
  for (i = 0, len = exports.names.length; i < len; i++) {
    if (exports.names[i].test(name)) {
      return true;
    }
  }
  return false;
}

/**
 * Coerce `val`.
 *
 * @param {Mixed} val
 * @return {Mixed}
 * @api private
 */

function coerce(val) {
  if (val instanceof Error) return val.stack || val.message;
  return val;
}

},{"ms":16}],16:[function(_dereq_,module,exports){
/**
 * Helpers.
 */

var s = 1000;
var m = s * 60;
var h = m * 60;
var d = h * 24;
var y = d * 365.25;

/**
 * Parse or format the given `val`.
 *
 * Options:
 *
 *  - `long` verbose formatting [false]
 *
 * @param {String|Number} val
 * @param {Object} options
 * @return {String|Number}
 * @api public
 */

module.exports = function(val, options){
  options = options || {};
  if ('string' == typeof val) return parse(val);
  return options.long
    ? long(val)
    : short(val);
};

/**
 * Parse the given `str` and return milliseconds.
 *
 * @param {String} str
 * @return {Number}
 * @api private
 */

function parse(str) {
  var match = /^((?:\d+)?\.?\d+) *(ms|seconds?|s|minutes?|m|hours?|h|days?|d|years?|y)?$/i.exec(str);
  if (!match) return;
  var n = parseFloat(match[1]);
  var type = (match[2] || 'ms').toLowerCase();
  switch (type) {
    case 'years':
    case 'year':
    case 'y':
      return n * y;
    case 'days':
    case 'day':
    case 'd':
      return n * d;
    case 'hours':
    case 'hour':
    case 'h':
      return n * h;
    case 'minutes':
    case 'minute':
    case 'm':
      return n * m;
    case 'seconds':
    case 'second':
    case 's':
      return n * s;
    case 'ms':
      return n;
  }
}

/**
 * Short format for `ms`.
 *
 * @param {Number} ms
 * @return {String}
 * @api private
 */

function short(ms) {
  if (ms >= d) return Math.round(ms / d) + 'd';
  if (ms >= h) return Math.round(ms / h) + 'h';
  if (ms >= m) return Math.round(ms / m) + 'm';
  if (ms >= s) return Math.round(ms / s) + 's';
  return ms + 'ms';
}

/**
 * Long format for `ms`.
 *
 * @param {Number} ms
 * @return {String}
 * @api private
 */

function long(ms) {
  return plural(ms, d, 'day')
    || plural(ms, h, 'hour')
    || plural(ms, m, 'minute')
    || plural(ms, s, 'second')
    || ms + ' ms';
}

/**
 * Pluralization helper.
 */

function plural(ms, n, name) {
  if (ms < n) return;
  if (ms < n * 1.5) return Math.floor(ms / n) + ' ' + name;
  return Math.ceil(ms / n) + ' ' + name + 's';
}

},{}],17:[function(_dereq_,module,exports){
(function (global){
/**
 * Module dependencies.
 */

var keys = _dereq_('./keys');
var hasBinary = _dereq_('has-binary');
var sliceBuffer = _dereq_('arraybuffer.slice');
var base64encoder = _dereq_('base64-arraybuffer');
var after = _dereq_('after');
var utf8 = _dereq_('utf8');

/**
 * Check if we are running an android browser. That requires us to use
 * ArrayBuffer with polling transports...
 *
 * http://ghinda.net/jpeg-blob-ajax-android/
 */

var isAndroid = navigator.userAgent.match(/Android/i);

/**
 * Check if we are running in PhantomJS.
 * Uploading a Blob with PhantomJS does not work correctly, as reported here:
 * https://github.com/ariya/phantomjs/issues/11395
 * @type boolean
 */
var isPhantomJS = /PhantomJS/i.test(navigator.userAgent);

/**
 * When true, avoids using Blobs to encode payloads.
 * @type boolean
 */
var dontSendBlobs = isAndroid || isPhantomJS;

/**
 * Current protocol version.
 */

exports.protocol = 3;

/**
 * Packet types.
 */

var packets = exports.packets = {
    open:     0    // non-ws
  , close:    1    // non-ws
  , ping:     2
  , pong:     3
  , message:  4
  , upgrade:  5
  , noop:     6
};

var packetslist = keys(packets);

/**
 * Premade error packet.
 */

var err = { type: 'error', data: 'parser error' };

/**
 * Create a blob api even for blob builder when vendor prefixes exist
 */

var Blob = _dereq_('blob');

/**
 * Encodes a packet.
 *
 *     <packet type id> [ <data> ]
 *
 * Example:
 *
 *     5hello world
 *     3
 *     4
 *
 * Binary is encoded in an identical principle
 *
 * @api private
 */

exports.encodePacket = function (packet, supportsBinary, utf8encode, callback) {
  if ('function' == typeof supportsBinary) {
    callback = supportsBinary;
    supportsBinary = false;
  }

  if ('function' == typeof utf8encode) {
    callback = utf8encode;
    utf8encode = null;
  }

  var data = (packet.data === undefined)
    ? undefined
    : packet.data.buffer || packet.data;

  if (global.ArrayBuffer && data instanceof ArrayBuffer) {
    return encodeArrayBuffer(packet, supportsBinary, callback);
  } else if (Blob && data instanceof global.Blob) {
    return encodeBlob(packet, supportsBinary, callback);
  }

  // might be an object with { base64: true, data: dataAsBase64String }
  if (data && data.base64) {
    return encodeBase64Object(packet, callback);
  }

  // Sending data as a utf-8 string
  var encoded = packets[packet.type];

  // data fragment is optional
  if (undefined !== packet.data) {
    encoded += utf8encode ? utf8.encode(String(packet.data)) : String(packet.data);
  }

  return callback('' + encoded);

};

function encodeBase64Object(packet, callback) {
  // packet data is an object { base64: true, data: dataAsBase64String }
  var message = 'b' + exports.packets[packet.type] + packet.data.data;
  return callback(message);
}

/**
 * Encode packet helpers for binary types
 */

function encodeArrayBuffer(packet, supportsBinary, callback) {
  if (!supportsBinary) {
    return exports.encodeBase64Packet(packet, callback);
  }

  var data = packet.data;
  var contentArray = new Uint8Array(data);
  var resultBuffer = new Uint8Array(1 + data.byteLength);

  resultBuffer[0] = packets[packet.type];
  for (var i = 0; i < contentArray.length; i++) {
    resultBuffer[i+1] = contentArray[i];
  }

  return callback(resultBuffer.buffer);
}

function encodeBlobAsArrayBuffer(packet, supportsBinary, callback) {
  if (!supportsBinary) {
    return exports.encodeBase64Packet(packet, callback);
  }

  var fr = new FileReader();
  fr.onload = function() {
    packet.data = fr.result;
    exports.encodePacket(packet, supportsBinary, true, callback);
  };
  return fr.readAsArrayBuffer(packet.data);
}

function encodeBlob(packet, supportsBinary, callback) {
  if (!supportsBinary) {
    return exports.encodeBase64Packet(packet, callback);
  }

  if (dontSendBlobs) {
    return encodeBlobAsArrayBuffer(packet, supportsBinary, callback);
  }

  var length = new Uint8Array(1);
  length[0] = packets[packet.type];
  var blob = new Blob([length.buffer, packet.data]);

  return callback(blob);
}

/**
 * Encodes a packet with binary data in a base64 string
 *
 * @param {Object} packet, has `type` and `data`
 * @return {String} base64 encoded message
 */

exports.encodeBase64Packet = function(packet, callback) {
  var message = 'b' + exports.packets[packet.type];
  if (Blob && packet.data instanceof Blob) {
    var fr = new FileReader();
    fr.onload = function() {
      var b64 = fr.result.split(',')[1];
      callback(message + b64);
    };
    return fr.readAsDataURL(packet.data);
  }

  var b64data;
  try {
    b64data = String.fromCharCode.apply(null, new Uint8Array(packet.data));
  } catch (e) {
    // iPhone Safari doesn't let you apply with typed arrays
    var typed = new Uint8Array(packet.data);
    var basic = new Array(typed.length);
    for (var i = 0; i < typed.length; i++) {
      basic[i] = typed[i];
    }
    b64data = String.fromCharCode.apply(null, basic);
  }
  message += global.btoa(b64data);
  return callback(message);
};

/**
 * Decodes a packet. Changes format to Blob if requested.
 *
 * @return {Object} with `type` and `data` (if any)
 * @api private
 */

exports.decodePacket = function (data, binaryType, utf8decode) {
  // String data
  if (typeof data == 'string' || data === undefined) {
    if (data.charAt(0) == 'b') {
      return exports.decodeBase64Packet(data.substr(1), binaryType);
    }

    if (utf8decode) {
      try {
        data = utf8.decode(data);
      } catch (e) {
        return err;
      }
    }
    var type = data.charAt(0);

    if (Number(type) != type || !packetslist[type]) {
      return err;
    }

    if (data.length > 1) {
      return { type: packetslist[type], data: data.substring(1) };
    } else {
      return { type: packetslist[type] };
    }
  }

  var asArray = new Uint8Array(data);
  var type = asArray[0];
  var rest = sliceBuffer(data, 1);
  if (Blob && binaryType === 'blob') {
    rest = new Blob([rest]);
  }
  return { type: packetslist[type], data: rest };
};

/**
 * Decodes a packet encoded in a base64 string
 *
 * @param {String} base64 encoded message
 * @return {Object} with `type` and `data` (if any)
 */

exports.decodeBase64Packet = function(msg, binaryType) {
  var type = packetslist[msg.charAt(0)];
  if (!global.ArrayBuffer) {
    return { type: type, data: { base64: true, data: msg.substr(1) } };
  }

  var data = base64encoder.decode(msg.substr(1));

  if (binaryType === 'blob' && Blob) {
    data = new Blob([data]);
  }

  return { type: type, data: data };
};

/**
 * Encodes multiple messages (payload).
 *
 *     <length>:data
 *
 * Example:
 *
 *     11:hello world2:hi
 *
 * If any contents are binary, they will be encoded as base64 strings. Base64
 * encoded strings are marked with a b before the length specifier
 *
 * @param {Array} packets
 * @api private
 */

exports.encodePayload = function (packets, supportsBinary, callback) {
  if (typeof supportsBinary == 'function') {
    callback = supportsBinary;
    supportsBinary = null;
  }

  var isBinary = hasBinary(packets);

  if (supportsBinary && isBinary) {
    if (Blob && !dontSendBlobs) {
      return exports.encodePayloadAsBlob(packets, callback);
    }

    return exports.encodePayloadAsArrayBuffer(packets, callback);
  }

  if (!packets.length) {
    return callback('0:');
  }

  function setLengthHeader(message) {
    return message.length + ':' + message;
  }

  function encodeOne(packet, doneCallback) {
    exports.encodePacket(packet, !isBinary ? false : supportsBinary, true, function(message) {
      doneCallback(null, setLengthHeader(message));
    });
  }

  map(packets, encodeOne, function(err, results) {
    return callback(results.join(''));
  });
};

/**
 * Async array map using after
 */

function map(ary, each, done) {
  var result = new Array(ary.length);
  var next = after(ary.length, done);

  var eachWithIndex = function(i, el, cb) {
    each(el, function(error, msg) {
      result[i] = msg;
      cb(error, result);
    });
  };

  for (var i = 0; i < ary.length; i++) {
    eachWithIndex(i, ary[i], next);
  }
}

/*
 * Decodes data when a payload is maybe expected. Possible binary contents are
 * decoded from their base64 representation
 *
 * @param {String} data, callback method
 * @api public
 */

exports.decodePayload = function (data, binaryType, callback) {
  if (typeof data != 'string') {
    return exports.decodePayloadAsBinary(data, binaryType, callback);
  }

  if (typeof binaryType === 'function') {
    callback = binaryType;
    binaryType = null;
  }

  var packet;
  if (data == '') {
    // parser error - ignoring payload
    return callback(err, 0, 1);
  }

  var length = ''
    , n, msg;

  for (var i = 0, l = data.length; i < l; i++) {
    var chr = data.charAt(i);

    if (':' != chr) {
      length += chr;
    } else {
      if ('' == length || (length != (n = Number(length)))) {
        // parser error - ignoring payload
        return callback(err, 0, 1);
      }

      msg = data.substr(i + 1, n);

      if (length != msg.length) {
        // parser error - ignoring payload
        return callback(err, 0, 1);
      }

      if (msg.length) {
        packet = exports.decodePacket(msg, binaryType, true);

        if (err.type == packet.type && err.data == packet.data) {
          // parser error in individual packet - ignoring payload
          return callback(err, 0, 1);
        }

        var ret = callback(packet, i + n, l);
        if (false === ret) return;
      }

      // advance cursor
      i += n;
      length = '';
    }
  }

  if (length != '') {
    // parser error - ignoring payload
    return callback(err, 0, 1);
  }

};

/**
 * Encodes multiple messages (payload) as binary.
 *
 * <1 = binary, 0 = string><number from 0-9><number from 0-9>[...]<number
 * 255><data>
 *
 * Example:
 * 1 3 255 1 2 3, if the binary contents are interpreted as 8 bit integers
 *
 * @param {Array} packets
 * @return {ArrayBuffer} encoded payload
 * @api private
 */

exports.encodePayloadAsArrayBuffer = function(packets, callback) {
  if (!packets.length) {
    return callback(new ArrayBuffer(0));
  }

  function encodeOne(packet, doneCallback) {
    exports.encodePacket(packet, true, true, function(data) {
      return doneCallback(null, data);
    });
  }

  map(packets, encodeOne, function(err, encodedPackets) {
    var totalLength = encodedPackets.reduce(function(acc, p) {
      var len;
      if (typeof p === 'string'){
        len = p.length;
      } else {
        len = p.byteLength;
      }
      return acc + len.toString().length + len + 2; // string/binary identifier + separator = 2
    }, 0);

    var resultArray = new Uint8Array(totalLength);

    var bufferIndex = 0;
    encodedPackets.forEach(function(p) {
      var isString = typeof p === 'string';
      var ab = p;
      if (isString) {
        var view = new Uint8Array(p.length);
        for (var i = 0; i < p.length; i++) {
          view[i] = p.charCodeAt(i);
        }
        ab = view.buffer;
      }

      if (isString) { // not true binary
        resultArray[bufferIndex++] = 0;
      } else { // true binary
        resultArray[bufferIndex++] = 1;
      }

      var lenStr = ab.byteLength.toString();
      for (var i = 0; i < lenStr.length; i++) {
        resultArray[bufferIndex++] = parseInt(lenStr[i]);
      }
      resultArray[bufferIndex++] = 255;

      var view = new Uint8Array(ab);
      for (var i = 0; i < view.length; i++) {
        resultArray[bufferIndex++] = view[i];
      }
    });

    return callback(resultArray.buffer);
  });
};

/**
 * Encode as Blob
 */

exports.encodePayloadAsBlob = function(packets, callback) {
  function encodeOne(packet, doneCallback) {
    exports.encodePacket(packet, true, true, function(encoded) {
      var binaryIdentifier = new Uint8Array(1);
      binaryIdentifier[0] = 1;
      if (typeof encoded === 'string') {
        var view = new Uint8Array(encoded.length);
        for (var i = 0; i < encoded.length; i++) {
          view[i] = encoded.charCodeAt(i);
        }
        encoded = view.buffer;
        binaryIdentifier[0] = 0;
      }

      var len = (encoded instanceof ArrayBuffer)
        ? encoded.byteLength
        : encoded.size;

      var lenStr = len.toString();
      var lengthAry = new Uint8Array(lenStr.length + 1);
      for (var i = 0; i < lenStr.length; i++) {
        lengthAry[i] = parseInt(lenStr[i]);
      }
      lengthAry[lenStr.length] = 255;

      if (Blob) {
        var blob = new Blob([binaryIdentifier.buffer, lengthAry.buffer, encoded]);
        doneCallback(null, blob);
      }
    });
  }

  map(packets, encodeOne, function(err, results) {
    return callback(new Blob(results));
  });
};

/*
 * Decodes data when a payload is maybe expected. Strings are decoded by
 * interpreting each byte as a key code for entries marked to start with 0. See
 * description of encodePayloadAsBinary
 *
 * @param {ArrayBuffer} data, callback method
 * @api public
 */

exports.decodePayloadAsBinary = function (data, binaryType, callback) {
  if (typeof binaryType === 'function') {
    callback = binaryType;
    binaryType = null;
  }

  var bufferTail = data;
  var buffers = [];

  var numberTooLong = false;
  while (bufferTail.byteLength > 0) {
    var tailArray = new Uint8Array(bufferTail);
    var isString = tailArray[0] === 0;
    var msgLength = '';

    for (var i = 1; ; i++) {
      if (tailArray[i] == 255) break;

      if (msgLength.length > 310) {
        numberTooLong = true;
        break;
      }

      msgLength += tailArray[i];
    }

    if(numberTooLong) return callback(err, 0, 1);

    bufferTail = sliceBuffer(bufferTail, 2 + msgLength.length);
    msgLength = parseInt(msgLength);

    var msg = sliceBuffer(bufferTail, 0, msgLength);
    if (isString) {
      try {
        msg = String.fromCharCode.apply(null, new Uint8Array(msg));
      } catch (e) {
        // iPhone Safari doesn't let you apply to typed arrays
        var typed = new Uint8Array(msg);
        msg = '';
        for (var i = 0; i < typed.length; i++) {
          msg += String.fromCharCode(typed[i]);
        }
      }
    }

    buffers.push(msg);
    bufferTail = sliceBuffer(bufferTail, msgLength);
  }

  var total = buffers.length;
  buffers.forEach(function(buffer, i) {
    callback(exports.decodePacket(buffer, binaryType, true), i, total);
  });
};

}).call(this,typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"./keys":18,"after":19,"arraybuffer.slice":20,"base64-arraybuffer":21,"blob":11,"has-binary":22,"utf8":24}],18:[function(_dereq_,module,exports){

/**
 * Gets the keys for an object.
 *
 * @return {Array} keys
 * @api private
 */

module.exports = Object.keys || function keys (obj){
  var arr = [];
  var has = Object.prototype.hasOwnProperty;

  for (var i in obj) {
    if (has.call(obj, i)) {
      arr.push(i);
    }
  }
  return arr;
};

},{}],19:[function(_dereq_,module,exports){
module.exports = after

function after(count, callback, err_cb) {
    var bail = false
    err_cb = err_cb || noop
    proxy.count = count

    return (count === 0) ? callback() : proxy

    function proxy(err, result) {
        if (proxy.count <= 0) {
            throw new Error('after called too many times')
        }
        --proxy.count

        // after first error, rest are passed to err_cb
        if (err) {
            bail = true
            callback(err)
            // future error callbacks will go to error handler
            callback = err_cb
        } else if (proxy.count === 0 && !bail) {
            callback(null, result)
        }
    }
}

function noop() {}

},{}],20:[function(_dereq_,module,exports){
/**
 * An abstraction for slicing an arraybuffer even when
 * ArrayBuffer.prototype.slice is not supported
 *
 * @api public
 */

module.exports = function(arraybuffer, start, end) {
  var bytes = arraybuffer.byteLength;
  start = start || 0;
  end = end || bytes;

  if (arraybuffer.slice) { return arraybuffer.slice(start, end); }

  if (start < 0) { start += bytes; }
  if (end < 0) { end += bytes; }
  if (end > bytes) { end = bytes; }

  if (start >= bytes || start >= end || bytes === 0) {
    return new ArrayBuffer(0);
  }

  var abv = new Uint8Array(arraybuffer);
  var result = new Uint8Array(end - start);
  for (var i = start, ii = 0; i < end; i++, ii++) {
    result[ii] = abv[i];
  }
  return result.buffer;
};

},{}],21:[function(_dereq_,module,exports){
/*
 * base64-arraybuffer
 * https://github.com/niklasvh/base64-arraybuffer
 *
 * Copyright (c) 2012 Niklas von Hertzen
 * Licensed under the MIT license.
 */
(function(chars){
  "use strict";

  exports.encode = function(arraybuffer) {
    var bytes = new Uint8Array(arraybuffer),
    i, len = bytes.length, base64 = "";

    for (i = 0; i < len; i+=3) {
      base64 += chars[bytes[i] >> 2];
      base64 += chars[((bytes[i] & 3) << 4) | (bytes[i + 1] >> 4)];
      base64 += chars[((bytes[i + 1] & 15) << 2) | (bytes[i + 2] >> 6)];
      base64 += chars[bytes[i + 2] & 63];
    }

    if ((len % 3) === 2) {
      base64 = base64.substring(0, base64.length - 1) + "=";
    } else if (len % 3 === 1) {
      base64 = base64.substring(0, base64.length - 2) + "==";
    }

    return base64;
  };

  exports.decode =  function(base64) {
    var bufferLength = base64.length * 0.75,
    len = base64.length, i, p = 0,
    encoded1, encoded2, encoded3, encoded4;

    if (base64[base64.length - 1] === "=") {
      bufferLength--;
      if (base64[base64.length - 2] === "=") {
        bufferLength--;
      }
    }

    var arraybuffer = new ArrayBuffer(bufferLength),
    bytes = new Uint8Array(arraybuffer);

    for (i = 0; i < len; i+=4) {
      encoded1 = chars.indexOf(base64[i]);
      encoded2 = chars.indexOf(base64[i+1]);
      encoded3 = chars.indexOf(base64[i+2]);
      encoded4 = chars.indexOf(base64[i+3]);

      bytes[p++] = (encoded1 << 2) | (encoded2 >> 4);
      bytes[p++] = ((encoded2 & 15) << 4) | (encoded3 >> 2);
      bytes[p++] = ((encoded3 & 3) << 6) | (encoded4 & 63);
    }

    return arraybuffer;
  };
})("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/");

},{}],22:[function(_dereq_,module,exports){
(function (global){

/*
 * Module requirements.
 */

var isArray = _dereq_('isarray');

/**
 * Module exports.
 */

module.exports = hasBinary;

/**
 * Checks for binary data.
 *
 * Right now only Buffer and ArrayBuffer are supported..
 *
 * @param {Object} anything
 * @api public
 */

function hasBinary(data) {

  function _hasBinary(obj) {
    if (!obj) return false;

    if ( (global.Buffer && global.Buffer.isBuffer(obj)) ||
         (global.ArrayBuffer && obj instanceof ArrayBuffer) ||
         (global.Blob && obj instanceof Blob) ||
         (global.File && obj instanceof File)
        ) {
      return true;
    }

    if (isArray(obj)) {
      for (var i = 0; i < obj.length; i++) {
          if (_hasBinary(obj[i])) {
              return true;
          }
      }
    } else if (obj && 'object' == typeof obj) {
      if (obj.toJSON) {
        obj = obj.toJSON();
      }

      for (var key in obj) {
        if (obj.hasOwnProperty(key) && _hasBinary(obj[key])) {
          return true;
        }
      }
    }

    return false;
  }

  return _hasBinary(data);
}

}).call(this,typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"isarray":23}],23:[function(_dereq_,module,exports){
module.exports = Array.isArray || function (arr) {
  return Object.prototype.toString.call(arr) == '[object Array]';
};

},{}],24:[function(_dereq_,module,exports){
(function (global){
/*! http://mths.be/utf8js v2.0.0 by @mathias */
;(function(root) {

	// Detect free variables `exports`
	var freeExports = typeof exports == 'object' && exports;

	// Detect free variable `module`
	var freeModule = typeof module == 'object' && module &&
		module.exports == freeExports && module;

	// Detect free variable `global`, from Node.js or Browserified code,
	// and use it as `root`
	var freeGlobal = typeof global == 'object' && global;
	if (freeGlobal.global === freeGlobal || freeGlobal.window === freeGlobal) {
		root = freeGlobal;
	}

	/*--------------------------------------------------------------------------*/

	var stringFromCharCode = String.fromCharCode;

	// Taken from http://mths.be/punycode
	function ucs2decode(string) {
		var output = [];
		var counter = 0;
		var length = string.length;
		var value;
		var extra;
		while (counter < length) {
			value = string.charCodeAt(counter++);
			if (value >= 0xD800 && value <= 0xDBFF && counter < length) {
				// high surrogate, and there is a next character
				extra = string.charCodeAt(counter++);
				if ((extra & 0xFC00) == 0xDC00) { // low surrogate
					output.push(((value & 0x3FF) << 10) + (extra & 0x3FF) + 0x10000);
				} else {
					// unmatched surrogate; only append this code unit, in case the next
					// code unit is the high surrogate of a surrogate pair
					output.push(value);
					counter--;
				}
			} else {
				output.push(value);
			}
		}
		return output;
	}

	// Taken from http://mths.be/punycode
	function ucs2encode(array) {
		var length = array.length;
		var index = -1;
		var value;
		var output = '';
		while (++index < length) {
			value = array[index];
			if (value > 0xFFFF) {
				value -= 0x10000;
				output += stringFromCharCode(value >>> 10 & 0x3FF | 0xD800);
				value = 0xDC00 | value & 0x3FF;
			}
			output += stringFromCharCode(value);
		}
		return output;
	}

	/*--------------------------------------------------------------------------*/

	function createByte(codePoint, shift) {
		return stringFromCharCode(((codePoint >> shift) & 0x3F) | 0x80);
	}

	function encodeCodePoint(codePoint) {
		if ((codePoint & 0xFFFFFF80) == 0) { // 1-byte sequence
			return stringFromCharCode(codePoint);
		}
		var symbol = '';
		if ((codePoint & 0xFFFFF800) == 0) { // 2-byte sequence
			symbol = stringFromCharCode(((codePoint >> 6) & 0x1F) | 0xC0);
		}
		else if ((codePoint & 0xFFFF0000) == 0) { // 3-byte sequence
			symbol = stringFromCharCode(((codePoint >> 12) & 0x0F) | 0xE0);
			symbol += createByte(codePoint, 6);
		}
		else if ((codePoint & 0xFFE00000) == 0) { // 4-byte sequence
			symbol = stringFromCharCode(((codePoint >> 18) & 0x07) | 0xF0);
			symbol += createByte(codePoint, 12);
			symbol += createByte(codePoint, 6);
		}
		symbol += stringFromCharCode((codePoint & 0x3F) | 0x80);
		return symbol;
	}

	function utf8encode(string) {
		var codePoints = ucs2decode(string);

		// console.log(JSON.stringify(codePoints.map(function(x) {
		// 	return 'U+' + x.toString(16).toUpperCase();
		// })));

		var length = codePoints.length;
		var index = -1;
		var codePoint;
		var byteString = '';
		while (++index < length) {
			codePoint = codePoints[index];
			byteString += encodeCodePoint(codePoint);
		}
		return byteString;
	}

	/*--------------------------------------------------------------------------*/

	function readContinuationByte() {
		if (byteIndex >= byteCount) {
			throw Error('Invalid byte index');
		}

		var continuationByte = byteArray[byteIndex] & 0xFF;
		byteIndex++;

		if ((continuationByte & 0xC0) == 0x80) {
			return continuationByte & 0x3F;
		}

		// If we end up here, it’s not a continuation byte
		throw Error('Invalid continuation byte');
	}

	function decodeSymbol() {
		var byte1;
		var byte2;
		var byte3;
		var byte4;
		var codePoint;

		if (byteIndex > byteCount) {
			throw Error('Invalid byte index');
		}

		if (byteIndex == byteCount) {
			return false;
		}

		// Read first byte
		byte1 = byteArray[byteIndex] & 0xFF;
		byteIndex++;

		// 1-byte sequence (no continuation bytes)
		if ((byte1 & 0x80) == 0) {
			return byte1;
		}

		// 2-byte sequence
		if ((byte1 & 0xE0) == 0xC0) {
			var byte2 = readContinuationByte();
			codePoint = ((byte1 & 0x1F) << 6) | byte2;
			if (codePoint >= 0x80) {
				return codePoint;
			} else {
				throw Error('Invalid continuation byte');
			}
		}

		// 3-byte sequence (may include unpaired surrogates)
		if ((byte1 & 0xF0) == 0xE0) {
			byte2 = readContinuationByte();
			byte3 = readContinuationByte();
			codePoint = ((byte1 & 0x0F) << 12) | (byte2 << 6) | byte3;
			if (codePoint >= 0x0800) {
				return codePoint;
			} else {
				throw Error('Invalid continuation byte');
			}
		}

		// 4-byte sequence
		if ((byte1 & 0xF8) == 0xF0) {
			byte2 = readContinuationByte();
			byte3 = readContinuationByte();
			byte4 = readContinuationByte();
			codePoint = ((byte1 & 0x0F) << 0x12) | (byte2 << 0x0C) |
				(byte3 << 0x06) | byte4;
			if (codePoint >= 0x010000 && codePoint <= 0x10FFFF) {
				return codePoint;
			}
		}

		throw Error('Invalid UTF-8 detected');
	}

	var byteArray;
	var byteCount;
	var byteIndex;
	function utf8decode(byteString) {
		byteArray = ucs2decode(byteString);
		byteCount = byteArray.length;
		byteIndex = 0;
		var codePoints = [];
		var tmp;
		while ((tmp = decodeSymbol()) !== false) {
			codePoints.push(tmp);
		}
		return ucs2encode(codePoints);
	}

	/*--------------------------------------------------------------------------*/

	var utf8 = {
		'version': '2.0.0',
		'encode': utf8encode,
		'decode': utf8decode
	};

	// Some AMD build optimizers, like r.js, check for specific condition patterns
	// like the following:
	if (
		typeof define == 'function' &&
		typeof define.amd == 'object' &&
		define.amd
	) {
		define(function() {
			return utf8;
		});
	}	else if (freeExports && !freeExports.nodeType) {
		if (freeModule) { // in Node.js or RingoJS v0.8.0+
			freeModule.exports = utf8;
		} else { // in Narwhal or RingoJS v0.7.0-
			var object = {};
			var hasOwnProperty = object.hasOwnProperty;
			for (var key in utf8) {
				hasOwnProperty.call(utf8, key) && (freeExports[key] = utf8[key]);
			}
		}
	} else { // in Rhino or a web browser
		root.utf8 = utf8;
	}

}(this));

}).call(this,typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{}],25:[function(_dereq_,module,exports){

/**
 * Module dependencies.
 */

var global = _dereq_('global');

/**
 * Module exports.
 *
 * Logic borrowed from Modernizr:
 *
 *   - https://github.com/Modernizr/Modernizr/blob/master/feature-detects/cors.js
 */

try {
  module.exports = 'XMLHttpRequest' in global &&
    'withCredentials' in new global.XMLHttpRequest();
} catch (err) {
  // if XMLHttp support is disabled in IE then it will throw
  // when trying to create
  module.exports = false;
}

},{"global":26}],26:[function(_dereq_,module,exports){

/**
 * Returns `this`. Execute this without a "context" (i.e. without it being
 * attached to an object of the left-hand side), and `this` points to the
 * "global" scope of the current JS execution.
 */

module.exports = (function () { return this; })();

},{}],27:[function(_dereq_,module,exports){

var indexOf = [].indexOf;

module.exports = function(arr, obj){
  if (indexOf) return arr.indexOf(obj);
  for (var i = 0; i < arr.length; ++i) {
    if (arr[i] === obj) return i;
  }
  return -1;
};
},{}],28:[function(_dereq_,module,exports){
(function (global){
/**
 * JSON parse.
 *
 * @see Based on jQuery#parseJSON (MIT) and JSON2
 * @api private
 */

var rvalidchars = /^[\],:{}\s]*$/;
var rvalidescape = /\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g;
var rvalidtokens = /"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g;
var rvalidbraces = /(?:^|:|,)(?:\s*\[)+/g;
var rtrimLeft = /^\s+/;
var rtrimRight = /\s+$/;

module.exports = function parsejson(data) {
  if ('string' != typeof data || !data) {
    return null;
  }

  data = data.replace(rtrimLeft, '').replace(rtrimRight, '');

  // Attempt to parse using the native JSON parser first
  if (global.JSON && JSON.parse) {
    return JSON.parse(data);
  }

  if (rvalidchars.test(data.replace(rvalidescape, '@')
      .replace(rvalidtokens, ']')
      .replace(rvalidbraces, ''))) {
    return (new Function('return ' + data))();
  }
};
}).call(this,typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{}],29:[function(_dereq_,module,exports){
/**
 * Compiles a querystring
 * Returns string representation of the object
 *
 * @param {Object}
 * @api private
 */

exports.encode = function (obj) {
  var str = '';

  for (var i in obj) {
    if (obj.hasOwnProperty(i)) {
      if (str.length) str += '&';
      str += encodeURIComponent(i) + '=' + encodeURIComponent(obj[i]);
    }
  }

  return str;
};

/**
 * Parses a simple querystring into an object
 *
 * @param {String} qs
 * @api private
 */

exports.decode = function(qs){
  var qry = {};
  var pairs = qs.split('&');
  for (var i = 0, l = pairs.length; i < l; i++) {
    var pair = pairs[i].split('=');
    qry[decodeURIComponent(pair[0])] = decodeURIComponent(pair[1]);
  }
  return qry;
};

},{}],30:[function(_dereq_,module,exports){
/**
 * Parses an URI
 *
 * @author Steven Levithan <stevenlevithan.com> (MIT license)
 * @api private
 */

var re = /^(?:(?![^:@]+:[^:@\/]*@)(http|https|ws|wss):\/\/)?((?:(([^:@]*)(?::([^:@]*))?)?@)?((?:[a-f0-9]{0,4}:){2,7}[a-f0-9]{0,4}|[^:\/?#]*)(?::(\d*))?)(((\/(?:[^?#](?![^?#\/]*\.[^?#\/.]+(?:[?#]|$)))*\/?)?([^?#\/]*))(?:\?([^#]*))?(?:#(.*))?)/;

var parts = [
    'source', 'protocol', 'authority', 'userInfo', 'user', 'password', 'host', 'port', 'relative', 'path', 'directory', 'file', 'query', 'anchor'
];

module.exports = function parseuri(str) {
    var src = str,
        b = str.indexOf('['),
        e = str.indexOf(']');

    if (b != -1 && e != -1) {
        str = str.substring(0, b) + str.substring(b, e).replace(/:/g, ';') + str.substring(e, str.length);
    }

    var m = re.exec(str || ''),
        uri = {},
        i = 14;

    while (i--) {
        uri[parts[i]] = m[i] || '';
    }

    if (b != -1 && e != -1) {
        uri.source = src;
        uri.host = uri.host.substring(1, uri.host.length - 1).replace(/;/g, ':');
        uri.authority = uri.authority.replace('[', '').replace(']', '').replace(/;/g, ':');
        uri.ipv6uri = true;
    }

    return uri;
};

},{}],31:[function(_dereq_,module,exports){

/**
 * Module dependencies.
 */

var global = (function() { return this; })();

/**
 * WebSocket constructor.
 */

var WebSocket = global.WebSocket || global.MozWebSocket;

/**
 * Module exports.
 */

module.exports = WebSocket ? ws : null;

/**
 * WebSocket constructor.
 *
 * The third `opts` options object gets ignored in web browsers, since it's
 * non-standard, and throws a TypeError if passed to the constructor.
 * See: https://github.com/einaros/ws/issues/227
 *
 * @param {String} uri
 * @param {Array} protocols (optional)
 * @param {Object) opts (optional)
 * @api public
 */

function ws(uri, protocols, opts) {
  var instance;
  if (protocols) {
    instance = new WebSocket(uri, protocols);
  } else {
    instance = new WebSocket(uri);
  }
  return instance;
}

if (WebSocket) ws.prototype = WebSocket.prototype;

},{}]},{},[1])(1)
});

index.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
  </head>
  <body>
    <div id="container"></div>
    <script src="/engine.io.js"></script>
    <script src="/client.js"></script>
  </body>
</html>

server.js

var http = require('http')
  , fs = require('fs');


var server = http.createServer(function (req, res) {
  if (req.url === '/client.js') {
    res.setHeader('Content-Type', 'application/javascript');
    fs.createReadStream(__dirname + '/client.js').pipe(res);
    return;
  }
  if (req.url === '/engine.io.js') {
    res.setHeader('Content-Type', 'application/javascript');
    fs.createReadStream(__dirname + '/engine.io.js').pipe(res);
    return;
  }
  res.setHeader('Content-Type', 'text/html');
  fs.createReadStream(__dirname + '/index.html').pipe(res);
});

var io = require('engine.io').attach(server);

io.on('connection', function (socket) {
  socket.send('foo');
  socket.send('bar');
  socket.send('baz');
  socket.close();
});

server.listen(3000, function () {
  console.log('server listening on port 3000');
});