pubsub.js

/*!
 * PubSub.js
 * ---------
 *
 * Extremely basic PubSub functionality.
 *
 * To subscribe to the topic `news`:
 *
 *    PubSub.on("news", function(str){
 *        alert(str);
 *    });
 *
 * To publish the topic `news`:
 *
 *    PubSub.trigger("news", "Extra extra!");
 *
 * To unsubscribe from the topic `news`:
 *
 *    PubSub.off("news");
 *
 * Copyright (c) 2013, T. Zengerink
 * Licensed under MIT License.
 * See: https://gist.github.com/raw/3151357/6806e68cb9cc0042b265f25be9bc25dd39f75267/LICENSE.md
 */
var PubSub = (function(){

  pubsub = {}, 
    subscriptions = {}; 

  // Unsubscribe
  pubsub.off = function( topic ){
    subscriptions[topic] = []; 
  };  

  // Subscribe
  pubsub.on = function( topic, fn ){
    if (typeof subscriptions[topic] === "undefined") {
      subscriptions[topic] = []; 
    }   
    subscriptions[topic].push(fn);
  };  

  // Publish
  pubsub.trigger = function( topic, args ){
    for (t in subscriptions[topic]) {
      typeof subscriptions[topic][t] === "function" && subscriptions[topic][t](args);
    }   
  };  

  return pubsub;

})();