PubSub with zepto... few fancy features like priorities and owner modules

zepto.pubsub.js

(function($) {

	var Subscription = function(t, c, o, p) {
			this.topic = t;
			this.callback = c;
			this.owner = o;
			this.priority = p || 10;
			this.signature = function(){
				return [t, c];
			};
			return this;
		},
		subscribers = {}
		filterArray = function(a, c){
			var i = 0;
			while (i < a.length) {
				if (c(a[i])) {
					a.splice(i, 1);
				} else { i++; }
			}
		};
	
	// Publish a pubsub event
	// topic = string
	// args (optional) = object, attached data
	// owner (optional) = string, only publishes to subscribers from that owner
	$.publish = function(topic, args, owner){
		if (subscribers['*']) {
			subscribers['*'].forEach(function(s){
				s.callback({ topic:topic, owner:owner, args:args });
			});
		}
		if (subscribers[topic]) {
			subscribers[topic].forEach(function(s){
				(owner && owner == s.owner) ? s.callback(args) : (!owner) && s.callback(args);
			});
		} else {
        	return null;
        }
	};
	// Subscribe to a pub sub event
	// topic = string or array (can subscribe to multiple events with same callback)
	// callback = function
	// o (optional) = string, owner
	// p (optional) = integer greater than 0, priority
	$.subscribe = function(topic, c, o, p){
		var handle=[];
		topic = (typeof topic == 'string') ? [topic] : topic;
		p = (o > 0) ? o : p;
		o = (o > 0) ? null : o;
		topic.forEach(function(t) {
			subscribers[t] = subscribers[t] || [];
			var s = new Subscription(t, c, o, p);
			subscribers[t].push(s);
			handle.push(s.signature());
			subscribers[t].sort(function(a, b){
				return (b.priority - a.priority);
			});
		});
		return (handle.length==1) ? handle[0] :  handle;
	};
	$.unsubscribe = function(topic, owner) {
		if (!topic && !owner) {
			// nuclear option
			subscribers = {};
		} else if (topic && !owner) {
			if (typeof topic == 'string') {
				// kill all subscribers of a certain topic
				subscribers[topic] = [];
			} else {
				// kill subscriber with a certain signature
				filterArray(subscribers[t], function(s){
					return (s.callback = topic[1]);
				});
			}
		} else if (topic && owner) {
			// kill all with a certain topic owned by a certain module
			filterArray(subscribers[topic], function(s){
				return (s.owner == owner);
			});
		} else if (!topic && owner) {
			// kill all owned by a certain module
			for (t in subscribers) {
				filterArray(subscribers[t], function(s){
					return (s.owner == owner);
				});
			}
		}
	};
	// Subscribers
	// topic = string
	// owner (optional) = string, only publishes to subscribers from that owner
	$.subscribers = function(topic, owner){
		var out = [],
			makeArray = function(t){
				subscribers[t] && subscribers[t].forEach(function(s){
					(owner && owner == s.owner) ? out.push(s) : (!owner) && out.push(s);
				});
			};
		(topic) ? makeArray(topic) : (function(){
			for (t in subscribers) {
				makeArray(t);
			}
		})();
		return out;
	};
	
})(Zepto);