function Event(name){

  this.name = name;

  this.callbacks = [];

}

Event.prototype.registerCallback = function(callback){

  this.callbacks.push(callback);

};

function Reactor(){

  this.events = {};

}

Reactor.prototype.registerEvent = function(eventName){

  var event = new Event(eventName);

  this.events[eventName] = event;

};

Reactor.prototype.dispatchEvent = function(eventName, eventArgs){

  this.events[eventName].callbacks.forEach(function(callback){

    callback(eventArgs);

  });

};

Reactor.prototype.addEventListener = function(eventName, callback){

  this.events[eventName].registerCallback(callback);

};

​

var reactor = new Reactor();

​

reactor.registerEvent('big bang');

​

reactor.addEventListener('big bang', function(){

  console.log('This is big bang listener yo!');

});

​

reactor.addEventListener('big bang', function(){

  console.log('This is another big bang listener yo!');

});

​

reactor.dispatchEvent('big bang');