Registers specified event handler
an event handler to register
Determines whether given event handler is already registered
an event handler to test
Invokes all event handlers subscribed on the event
Unregisters specified event handler
an event handler to unregister
Represents an event.
DataViews events are similar to .NET events. Any class may define events by declaring them as fields. Any class may subscribe to events using the Event.addHandler method, or unsubscribe using the Event.removeHandler method.
Event handlers take one parameter: args. It is an object that contains the the event parameters.