MessageBus.js

var messageBus = {
  //What is the realtionship between subscrib and publish?
  subscriberCallbacks: {},

  subscribe: function(title, callback) {
    
    if (!this.subscriberCallbacks[title]) {
      this.subscriberCallbacks[title] = [callback]
    } else {
      this.subscriberCallbacks[title].push(callback);
    }
  },

  //When you publish, you expect everyone subscribing to that title to recieve the payload
  //How do you keep trck of who is subscribing to the message Bus?
  publish: function(title, payload) {
    var subscribers = this.subscriberCallbacks[title];
    for (var sIndex = 0; sIndex < subscribers.length; sIndex++) {
      var callback = subscribers[sIndex];
      callback(payload); 
    }
  }

}



messageBus.subscribe('new_signup', function(payload) {
  console.log('a', payload);
})

messageBus.subscribe('new_signup', function(payload) {
  console.log('b', payload);
})
messageBus.subscribe('new_signup', function(payload) {
  console.log('c', payload);
})
messageBus.subscribe('new_signup', function(payload) {
  console.log('d', payload);
})
messageBus.subscribe('new_signup', function(payload) {
  console.log('e', payload);
})



messageBus.publish('new_signup', {'foo': 'bar', 'goo': 'gar'})