Struct starbase_events::Emitter

pub struct Emitter<E: Event> { /* private fields */ }

Implementations

impl<E: Event + 'static> Emitter<E>

pub fn new() -> Self

Create a new event emitter.

pub async fn len(&self) -> usize

Return a count of how many subscribers have been registered.

pub async fn subscribe<L: Subscriber<E> + 'static>( &self, subscriber: L ) -> &Self

Register a subscriber to receive events.

pub async fn on<L: SubscriberFunc<E> + 'static>(&self, callback: L) -> &Self

Register a subscriber function to receive events.

pub async fn once<L: SubscriberFunc<E> + 'static>(&self, callback: L) -> &Self

Register a subscriber function that will unregister itself after the first event is received. This is useful for one-time event handlers.

pub async fn emit(&self, event: E) -> Result<E::Data>

Emit the provided event to all registered subscribers. Subscribers will be called in the order they were registered.

If a subscriber returns EventState::Stop, no further subscribers will be called. If a subscriber returns [EventState::Return], no further subscribers will be called and the provided value will be returned. If a subscriber returns EventState::Continue, the next subscriber will be called.

When complete, the provided event will be returned along with the value returned by the subscriber that returned [EventState::Return], or None if not occurred.