Pub/Sub JavaScript Object http://davidwalsh.name/pubsub-javascript

pubsub.js

module.exports = (function() {
  "use strict";

  var topics = {};
  return {

    subscribe: function (topic, listener) {
      // Create the topic's object if not yet created
      if (!topics[topic])
        topics[topic] = { queue: [] }

      // Add the listener to the queue
      var index = topics[topic].queue.push(listener) - 1;

      // Provide handle back for removal of topic
      return (function (topic, index) {
          return {
            remove: function () {
              delete topics[topic].queue[index];
            }
          }
        })(topic, index);
    },

    publish: function (topic, info) {
      // If the topic doesn't exist, or there's no listeners in queue, just leave
      if (!topics[topic] || !topics[topic].queue.length) return;

      // Cycle through topics queue, fire!
      var items = topics[topic].queue;
      items.forEach(function (item) {
        item(info||{});
      });
    }
  }

})();

usage.js

var events = require('./pubsub');

(function() {
  "use strict";
  var App = {
    Events: events,

    init: function () {
      
      // Pusblish Events
      App.Events.publish('/page/load', {
        url: '/some/url/path',
      });
      
      // Subscribe Events
      App.Events.subscribe('/page/load', function () {
        console.log("Event Page/Load detected and triggered event in FeatureA module");
      });
      
      

    }
  };

  window.App = App;

}());