/*	

jQuery pub/sub plugin by Peter Higgins (dante@dojotoolkit.org)

Loosely based on Dojo publish/subscribe API, limited in scope. Rewritten blindly.

Original is (c) Dojo Foundation 2004-2009. Released under either AFL or new BSD, see:
http://dojofoundation.org/license for more information.

*/

; (function (d) {

    // the topic/subscription hash
    var cache = {};

    d.publish = function (/* String */topic, /* Array? */args) {
        // summary: 
        //		Publish some data on a named topic.
        // topic: String
        //		The channel to publish on
        // args: Array?
        //		The data to publish. Each array item is converted into an ordered
        //		arguments on the subscribed functions. 
        //
        // example:
        //		Publish stuff on '/some/topic'. Anything subscribed will be called
        //		with a function signature like: function(a,b,c){ ... }
        //
        //	|		$.publish("/some/topic", ["a","b","c"]);
        d.each(cache[topic], function () {
            this.apply(d, args || []);
        });
    };

    d.subscribe = function (/* String */topic, /* Function */callback) {
        // summary:
        //		Register a callback on a named topic.
        // topic: String
        //		The channel to subscribe to
        // callback: Function
        //		The handler event. Anytime something is $.publish'ed on a 
        //		subscribed channel, the callback will be called with the
        //		published array as ordered arguments.
        //
        // returns: Array
        //		A handle which can be used to unsubscribe this particular subscription.
        //	
        // example:
        //	|	$.subscribe("/some/topic", function(a, b, c){ /* handle data */ });
        //
        if (!cache[topic]) {
            cache[topic] = [];
        }
        cache[topic].push(callback);
        return [topic, callback]; // Array
    };

    d.unsubscribe = function (/* Array */handle) {
        // summary:
        //		Disconnect a subscribed function for a topic.
        // handle: Array
        //		The return value from a $.subscribe call.
        // example:
        //	|	var handle = $.subscribe("/something", function(){});
        //	|	$.unsubscribe(handle);

        var t = handle[0];
        cache[t] && d.each(cache[t], function (idx) {
            if (this == handle[1]) {
                cache[t].splice(idx, 1);
            }
        });
    };

})(jQuery);