Class comb.plugins.Broadcaster

Class Detail

comb.plugins.Broadcaster()

Plugin to allow a class to easily broadcast events

Example 1 :

var Mammal = define(comb.plugins.Broadcaster, {
  instance : {

     constructor: function(options) {
         options = options || {};
         this._super(arguments);
         this._type = options.type || "mammal";
     },

     speak : function() {
         var str = "A mammal of type " + this._type + " sounds like";
         this.broadcast("speak", str);
         this.onSpeak(str);
         return str;
     },

     onSpeak : function(){}
   }
});


var m = new Mammal({color : "gold"});
m.listen("speak", function(str){
     //called back from the broadcast event
      console.log(str);
});
m.speak();

this.__listeners = {};

Method Detail

broadcast(name, args)

Broadcasts an event from an object

Parameters:
name: the name of the event to broadcast
{Object|String|Function|Date|Number} args Optional: variable number of arguments to pass to listeners, can be anything

var args = Array.prototype.slice.call(arguments, 0), topic = args.shift();
if (topic && topic in this.__listeners) {
	var list = this.__listeners[topic], i = list.length - 1;
	while (i >= 0) {
		list[i--].cb.apply(this, args);
	}
}

{Array} listen(topic, callback)

Listens to a broadcasted event Simimlar to comb.listen

Parameters:
{String} topic: the topic to listen to
{Function} callback: the function to callback on event publish

Returns:: {Array} handle to disconnect a topic

if (!func.isFunction(callback)) throw new Error("callback must be a function");
var handle = {
	topic : topic,
	cb : callback
};
var list = this.__listeners[topic];
if (!list) {
	list = (this.__listeners[topic] = [handle]);
	handle.pos = 0;
} else {
	handle.pos = list.push(handle);
}
return handle;

unListen(handle)

Disconnects a listener Similar to comb.unListen

Parameters:
handle: disconnect a handle returned from Broadcaster.listen

if (handle) {
	var topic = handle.topic;
	if (topic in this.__listeners) {
		var listeners = this.__listeners, list = listeners[topic];
		if (list) {
			for (var i = list.length - 1; i >= 0; i--) {
				if (list[i] == handle) {
					list.splice(i, 1);
					break;
				}
			}
		}
	}
}