Event
Controls how a new event of the same type is handled while a previous handler is still active or pending.
Attach a transformer when registering a handler in a Bloc:
on<SearchEvent.Query>(transformer = EventTransformer.Debounce(300.milliseconds)) { event, emit ->
performSearch(event.query, emit)
}| Transformer | Behaviour | Best for |
|---|---|---|
| Sequential | Default. Processes events one at a time in order. | Counters, toggles |
| Concurrent | Each event gets its own coroutine, all run in parallel. | Independent fire-and-forget ops |
| Droppable | Ignores new events while the previous handler coroutine is active. | Expensive one-shot ops |
| Restartable | Cancels the running handler and starts fresh with the new event. | "Load latest" patterns |
| Debounce | Waits for a quiet period; each new event resets the timer. | Live search |
| Throttle | Fires immediately, then ignores events for the duration. | Scroll-triggered pagination |
Inheritors
Types
Run each event handler in its own coroutine concurrently.
Wait for duration of silence before invoking the handler. Each new event resets the countdown. The handler is called only once after the quiet period expires.
Silently drop incoming events while a previous handler coroutine is still running. The first event fires immediately; duplicates are discarded until the job completes.
Cancel the currently running handler coroutine and start a fresh one for the new event. Ideal for "fetch latest" patterns where only the most recent request matters.
Process events one at a time in arrival order. This is the default.
Invoke the handler immediately for the first event, then suppress further events for duration.