Javascript: Pub/Sub Design pattern (Observer Pattern)

pubsub.js

var PubSub = {};    //create empty object!

(function(p){

	"use strict";
	var topics = {},
	lastUid = -1;


	var publish = function( topic , data){

		if ( !topics.hasOwnProperty( topic ) ){
			return false;
		}


		var notify = function(){
			var subscribers = topics[topic],
			throwException = function(e){
				return function(){
					throw e;
				};

			};

			for ( var i = 0, j = subscribers.length; i < j; i++ ){
				try {
					subscribers[i].func( topic, data );
				} catch( e ){

					setTimeout( throwException(e), 0);
				}
			}
		};

		 setTimeout( notify , 0 );  //즉시 notify 메소드 실행
		 return true;
	};



	 /**
	*  Publishes the topic, passing the data to it's subscribers
	*  @topic (String): The topic to publish
	*  @data: The data to pass to subscribers
	**/

	p.publish = function( topic, data ){
		return publish( topic, data, false );
	};


	 /**
	*  Subscribes the passed function to the passed topic.
	*  Every returned token is unique and should be stored if you need to unsubscribe
	*  @topic (String): The topic to subscribe to
	*  @func (Function): The function to call when a new topic is published
	**/

	p.subscribe = function( topic, func ){

		 // topic is not registered yet
		 if ( !topics.hasOwnProperty( topic ) ){
			topics[topic] = [];
		 }

		 var token = (++lastUid).toString();
		 topics[topic].push( { token : token, func : func } );

		 // return token for unsubscribing
		 return token;

	};

	 /**
	*  Unsubscribes a specific subscriber from a specific topic using the unique token
	*  @token (String): The token of the function to unsubscribe
	**/

	p.unsubscribe = function( token ){

		for ( var m in topics ){
			if ( topics.hasOwnProperty( m ) ){
				for ( var i = 0, j = topics[m].length; i < j; i++ ){
					if ( topics[m][i].token === token ){
						topics[m].splice( i, 1 );
						return token;
					}
				}
			}
		}
		return false;
	};
});


// a sample subscriber (or observer)

var testSubscriber = function( topics , data ){
   console.log( topics + ": " + data );

};



// add the function to the list of subscribers to a particular topic
// maintain the token (subscription instance) to enable unsubscription later

var testSubscription = PubSub.subscribe( 'example1', testSubscriber );

// publish a topic or message asyncronously

PubSub.publish( 'example1', 'hello scriptjunkie!' );
PubSub.publish( 'example1', ['test','a','b','c'] );
PubSub.publish( 'example1', [{'color':'blue'},{'text':'hello'}] );

// unsubscribe from further topics
setTimeout(function(){
   PubSub.unsubscribe( testSubscription );
}, 0);

// test that we've fully unsubscribed
PubSub.publish( 'example1', 'hello again!');