pubsub.js

pubsub.js

/**
	 *	Events. Pub/Sub system for Loosely Coupled logic.
	 *	Based on Peter Higgins' port from Dojo to jQuery
	 *	https://github.com/phiggins42/bloody-jquery-plugins/blob/master/pubsub.js
	 *
	 *	Re-adapted to vanilla Javascript by @Couto https://github.com/Couto
	 *
	 *	@class Events
	 */
	var Events = (function (){
		var cache = {},
			/**
			 *	Events.publish
			 *	e.g.: Events.publish("/Article/added", [article], this);
			 *
			 *	@class Events
			 *	@method publish
			 *	@param topic {String}
			 *	@param args	{Array}
			 *	@param scope {Object} Optional
			 */
			publish = function (topic, args, scope) {
				if (cache[topic]) {
					var thisTopic = cache[topic],
						i = thisTopic.length - 1;

					for (i; i >= 0; i -= 1) {
						thisTopic[i].apply( scope || this, args || []);
					}
				}
			},
			/**
			 *	Events.subscribe
			 *	e.g.: Events.subscribe("/Article/added", Articles.validate)
			 *
			 *	@class Events
			 *	@method subscribe
			 *	@param topic {String}
			 *	@param callback {Function}
			 *	@return Event handler {Array}
			 */
			subscribe = function (topic, callback) {
				if (!cache[topic]) {
					cache[topic] = [];
				}
				cache[topic].push(callback);
				return [topic, callback];
			},
			/**
			 *	Events.unsubscribe
			 *	e.g.: var handle = Events.subscribe("/Article/added", Articles.validate);
			 *		Events.unsubscribe(handle);
			 *
			 *	@class Events
			 *	@method unsubscribe
			 *	@param handle {Array}
			 *	@param completly {Boolean}
			 *	@return {type description }
			 */
			unsubscribe = function (handle, completly) {
				var t = handle[0],
					i = cache[t].length - 1;

				if (cache[t]) {
					for (i; i >= 0; i -= 1) {
						if (cache[t][i] === handle[1]) {
							cache[t].splice(cache[t][i], 1);
							if(completly){ delete cache[t]; }
						}
					}
				}
			};

		return {
			publish: publish,
			subscribe: subscribe,
			unsubscribe: unsubscribe
		};
}());