Listeners

A listener is an instance of a class which can be registered to receive lifecycle events or decorator behavior.

You can also turn arbitrary objects into listeners as long as you supply the necessary reflection metadata for lifecycle events/decorators (flamework:implements and flamework:decorators) respectively but it is easiest to use classes and let Flamework do this automatically.

Adding a listener

You can use the Modding.addListener API to create a listener. Flamework will automatically fire relevant events (e.g onListenerAdded) based on the flamework:implements metadata as well the flamework:decorators metadata.

Flamework automatically adds all singletons, components or custom classes (when using Modding.createDependency) as listeners.

@Decorator()
class A implements LifecycleEvent {}

Modding.addListener(new A());

Removing a listener

You can use the Modding.removeListener API to remove a listener. Flamework will automatically fire relevant events (e.g onListenerRemoved) based on the flamework:implements metadata as well the flamework:decorators metadata.

Lifecycle events will no longer fire once the object is removed as a listener.

@Decorator()
class A implements LifecycleEvent {}

const obj = new A();
Modding.addListener(obj);
// some time later
Modding.removeListener(obj);

Listener added/removed

Flamework exposes an onListenerAdded event as well as an onListenerRemoved. These events can be fired for any listener or you can specify a specific ID to listen for (Flamework only fires these events for decorator/lifecycle event IDs.)

// Fires when any listener is added.
Modding.onListenerAdded((obj) => {
	print("new listener!", obj);
})

// Fires when any listener is removed.
Modding.onListenerRemoved((obj) => {
	print("listener was removed!", obj);
})

// Fires whenever a listener subscribed to the MyLifecycle lifecycle event was added.
Modding.onListenerAdded<MyLifecycle>((obj) => {
	print("new listener for MyLifecycle!", obj);
	obj.myLifecycle();
})

// Fires whenever a listener subscribed to the MyLifecycle lifecycle event was removed.
Modding.onListenerRemoved<MyLifecycle>((obj) => {
	print("listener for MyLifecycle was removed!", obj);
})