javascript pub/sub

pub_sub.js

var events = (function(){                                                       
  var topics = {};                                                              
                                                                                
  function getQueue(topic) {                                                    
    topics[topic] = topics[topic] || [];                                                       
    return topics[topic];                                                       
  }                                                                             
                                                                                
  return {                                                                      
    subscribe: function(topic, listener) {                                      
      var index = getQueue(topic).push(listener) - 1;                           
    },                                                                          
    remove: function(topic, listener) {                                         
      queue = getQueue(topic);                                                  
      index = queue.indexOf(listener);                                          
      delete queue[index];                                                      
    },                                                                          
    publish: function(topic, info) {                                            
      if(!topics[topic] || !topics[topic].queue.length) return;                 
                                                                                
      var items = topics[topic].queue;                                          
      getQueue(topic).forEach(function(listener) {                              
        listener(info || {});                                                   
      });                                                                       
    }                                                                           
  };                                                                            
})();