Objects implementing this interface can emit events.
Represents the transport class of events across the system. It receives a name, subject and an optional payload. The name can be any string that uniquely identifies the event across the application, while the subject represents the object that the event applies to.
Objects implementing this interface should declare the
to notify the event manager what methods should be called when an event is triggered.
The Event List
The event manager is responsible for keeping track of event listeners, passing the correct data to them, and firing them in the correct order, when associated events are triggered. You can create multiple instances of this object to manage local events or keep a single instance and pass it around to manage all events in your app.