Notice one thing in the previous scenario: to listen to the loggedin event, all the other components of the application should have a reference to that loginView. Is this really required? It may seem to a few components that keeping a reference to loginView is irrelevant, but they have to do so because they need to listen to the loggedin event on this loginView object. Dependency injection in such a way can be painful even when you are developing a simple application. Sometimes we may need a common object that will play the role of a central event manager and can be used throughout the application to trigger and listen to events. The simplest event dispatcher can be defined in the following way:

var vent = _.extend({}, Backbone.Events);

// Listen to a custom event
vent.on('customevent', function(){
  console.log('Custom event fired');
});

// Fire the event
vent.trigger('customevent');

When we make the vent variable available at the application-level, it can work...