pubsub.js

  /*
   * Simple Pub/Sub Implementation for jQuery
   *
   * Inspired by work from Peter Higgins (https://github.com/phiggins42/bloody-jquery-plugins/blob/master/pubsub.js)
   *
   * This is about the simplest way to write a pubsub JavaScript implementation for use with jQuery.
   */
  
  (function($) {
    // Cache of all topics
    var topics = {};
  
    // Iterates through all subscribers of a topic and invokes their callback,
    // passing optional arguments.
    $.publish = function(topic, args) {
      if (topics[topic]) {
        var thisTopic = topics[topic],
            thisArgs = args || [];
  
        for (var i = 0, j = thisTopic.length; i < j; i++) {
          thisTopic[i].apply($, thisArgs);
        }
      }
    };
  
    // Returns a handle needed for unsubscribing
    $.subscribe = function(topic, callback) {
      if (!topics[topic]) {
        topics[topic] = [];
      }
  
      topics[topic].push(callback);
  
      return {
        topic: topic,
        callback: callback
      };
    };
  
    // Removes the subscriber from the particular topic its handle was assigned to
    $.unsubscribe = function(handle) {
      var topic = handle.topic;
  
      if (topics[topic]) {
        var thisTopic = topics[topic];
  
        for (var i = 0, j = thisTopic.length; i < j; i++) {
          if (thisTopic[i] === handle.callback) {
            thisTopic.splice(i, 1);
            // break; here? duplicate handles are possible
          }
        }
      }
    };
  
  })(jQuery);

nice