Minimal PubSub solution

pubsub.js

// Original code by David Walsh: http://davidwalsh.name/pubsub-javascript
var events = (function(){
  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 queue
      var index = topics[topic].queue.push(listener);

      // Provide handle back for removal of topic
      return (function(index) {
        return {
          remove: function() {
            delete topics[index];
          }
        }
      })(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;
      for(var x = 0; x < items.length; x++) {
        items[x](info || {});
      }
    }
  };
})();