jQuery Pub/Sub plugin v0.2

/*
    jQuery pub/sub plugin by Túbal Martín (http://margenn.com)

    Inspired by Peter Higgings plugin: https://github.com/phiggins42/bloody-jquery-plugins/blob/8ccf0da40b85fa4ecc30079c8650bac58f7a334c/pubsub.js
*/

(function($) {

    // The topics/subscriptions hash
    var topics = {};

    /**
     * @description Publishes some data on a named topic.
     * @param {String} topic The topic to publish.
     * @param {Array} [args] The data to publish.
     * @returns {jQuery} returns jQuery object.
     * @example
     * $( "#sidebarWidget" ).publish( "/some/topic", [ "a", "b", "c" ] );
     */
    $.fn.publish = function ( topic, args ) {
        args = args || [],
        argsLength = args.length;

        if ( topics[topic] ) {
            this.each( function( i, obj ) {
                // Let's add a reference to the publisher object
                args[argsLength] = obj;
                $.each( topics[topic], function( j, aElem ) {
                    aElem.callback.apply( aElem.object, args );
                });
            });
        }

        return this;
    };


    /**
     * @description Registers a callback on a named topic.
     * @param {String} topic The topic to subscribe to.
     * @param {Function} callback The handler. Anytime something is published on a subscribed
     * topic, the callback will be called with the published array as ordered arguments.
     * @returns {jQuery} returns jQuery object.
     * @example
     * $( "#header" ).subscribe( "/some/topic", function( a, b, c ) { // handle data } );
     */
    $.fn.subscribe = function( topic, callback ) {
        topics[topic] = topics[topic] || [];

        this.each( function( i, obj ) {
            // Array.push() is way slower. See: http://jsperf.com/array-push-el-vs-array-array-length-el
            topics[topic][topics[topic].length] = { "object": obj, "callback": callback };
        });

        return this;
    };


    /**
     * @description Unregisters a previously registered callback for a named topic.
     * @param {String} topic The topic to unsubscribe from.
     * @returns {jQuery} returns jQuery object.
     * @example
     * $( "#header" ).unsubscribe( "/some/topic" );
     */
    $.fn.unsubscribe = function ( topic ) {

        if ( topics[topic] ) {
            this.each( function( i, obj ) {
                topics[topic] = $.grep( topics[topic], function( aElem, j ) {
                    return ( obj !== aElem.object );
                });
            });

            if ( topics[topic].length === 0 ) {
                delete topics[topic];
            }
        }

        return this;
    };

}(jQuery));