node/node_modules/socket.io-client/lib/events.js

   1
   2 /**
   3  * socket.io
   4  * Copyright(c) 2011 LearnBoost <dev@learnboost.com>
   5  * MIT Licensed
   6  */
   7
   8 (function (exports, io) {
   9
  10   /**
  11    * Expose constructor.
  12    */
  13
  14   exports.EventEmitter = EventEmitter;
  15
  16   /**
  17    * Event emitter constructor.
  18    *
  19    * @api public.
  20    */
  21
  22   function EventEmitter () {};
  23
  24   /**
  25    * Adds a listener
  26    *
  27    * @api public
  28    */
  29
  30   EventEmitter.prototype.on = function (name, fn) {
  31     if (!this.$events) {
  32       this.$events = {};
  33     }
  34
  35     if (!this.$events[name]) {
  36       this.$events[name] = fn;
  37     } else if (io.util.isArray(this.$events[name])) {
  38       this.$events[name].push(fn);
  39     } else {
  40       this.$events[name] = [this.$events[name], fn];
  41     }
  42
  43     return this;
  44   };
  45
  46   EventEmitter.prototype.addListener = EventEmitter.prototype.on;
  47
  48   /**
  49    * Adds a volatile listener.
  50    *
  51    * @api public
  52    */
  53
  54   EventEmitter.prototype.once = function (name, fn) {
  55     var self = this;
  56
  57     function on () {
  58       self.removeListener(name, on);
  59       fn.apply(this, arguments);
  60     };
  61
  62     on.listener = fn;
  63     this.on(name, on);
  64
  65     return this;
  66   };
  67
  68   /**
  69    * Removes a listener.
  70    *
  71    * @api public
  72    */
  73
  74   EventEmitter.prototype.removeListener = function (name, fn) {
  75     if (this.$events && this.$events[name]) {
  76       var list = this.$events[name];
  77
  78       if (io.util.isArray(list)) {
  79         var pos = -1;
  80
  81         for (var i = 0, l = list.length; i < l; i++) {
  82           if (list[i] === fn || (list[i].listener && list[i].listener === fn)) {
  83             pos = i;
  84             break;
  85           }
  86         }
  87
  88         if (pos < 0) {
  89           return this;
  90         }
  91
  92         list.splice(pos, 1);
  93
  94         if (!list.length) {
  95           delete this.$events[name];
  96         }
  97       } else if (list === fn || (list.listener && list.listener === fn)) {
  98         delete this.$events[name];
  99       }
 100     }
 101
 102     return this;
 103   };
 104
 105   /**
 106    * Removes all listeners for an event.
 107    *
 108    * @api public
 109    */
 110
 111   EventEmitter.prototype.removeAllListeners = function (name) {
 112     // TODO: enable this when node 0.5 is stable
 113     //if (name === undefined) {
 114       //this.$events = {};
 115       //return this;
 116     //}
 117
 118     if (this.$events && this.$events[name]) {
 119       this.$events[name] = null;
 120     }
 121
 122     return this;
 123   };
 124
 125   /**
 126    * Gets all listeners for a certain event.
 127    *
 128    * @api publci
 129    */
 130
 131   EventEmitter.prototype.listeners = function (name) {
 132     if (!this.$events) {
 133       this.$events = {};
 134     }
 135
 136     if (!this.$events[name]) {
 137       this.$events[name] = [];
 138     }
 139
 140     if (!io.util.isArray(this.$events[name])) {
 141       this.$events[name] = [this.$events[name]];
 142     }
 143
 144     return this.$events[name];
 145   };
 146
 147   /**
 148    * Emits an event.
 149    *
 150    * @api public
 151    */
 152
 153   EventEmitter.prototype.emit = function (name) {
 154     if (!this.$events) {
 155       return false;
 156     }
 157
 158     var handler = this.$events[name];
 159
 160     if (!handler) {
 161       return false;
 162     }
 163
 164     var args = Array.prototype.slice.call(arguments, 1);
 165
 166     if ('function' == typeof handler) {
 167       handler.apply(this, args);
 168     } else if (io.util.isArray(handler)) {
 169       var listeners = handler.slice();
 170
 171       for (var i = 0, l = listeners.length; i < l; i++) {
 172         listeners[i].apply(this, args);
 173       }
 174     } else {
 175       return false;
 176     }
 177
 178     return true;
 179   };
 180
 181 })(
 182     'undefined' != typeof io ? io : module.exports
 183   , 'undefined' != typeof io ? io : module.parent.exports
 184 );