T - the value type to emitpublic interface FlowableEmitter<T> extends Emitter<T>
Subscriber that allows associating
a resource with it and exposes the current number of downstream
requested amount.
The Emitter.onNext(Object), Emitter.onError(Throwable), tryOnError(Throwable)
and Emitter.onComplete() methods should be called in a sequential manner, just like
the Subscriber's methods.
Use the FlowableEmitter the serialize() method returns instead of the original
FlowableEmitter instance provided by the generator routine if you want to ensure this.
The other methods are thread-safe.
The emitter allows the registration of a single resource, in the form of a Disposable
or Cancellable via setDisposable(Disposable) or setCancellable(Cancellable)
respectively. The emitter implementations will dispose/cancel this instance when the
downstream cancels the flow or after the event generator logic calls Emitter.onError(Throwable),
Emitter.onComplete() or when tryOnError(Throwable) succeeds.
Only one Disposable or Cancellable object can be associated with the emitter at
a time. Calling either set method will dispose/cancel any previous object. If there
is a need for handling multiple resources, one can create a CompositeDisposable
and associate that with the emitter instead.
The Cancellable is logically equivalent to Disposable but allows using cleanup logic that can
throw a checked exception (such as many close() methods on Java IO components). Since
the release of resources happens after the terminal events have been delivered or the sequence gets
cancelled, exceptions throw within Cancellable are routed to the global error handler via
RxJavaPlugins.onError(Throwable).
| Modifier and Type | Method and Description |
|---|---|
boolean |
isCancelled ()
Returns true if the downstream cancelled the sequence or the
emitter was terminated via
Emitter.onError(Throwable), Emitter.onComplete() or a
successful tryOnError(Throwable). |
long |
requested ()
The current outstanding request amount.
|
FlowableEmitter<T> |
serialize ()
Ensures that calls to onNext, onError and onComplete are properly serialized.
|
void |
setCancellable (Cancellable c)
Sets a Cancellable on this emitter; any previous
Disposable
or Cancellable will be disposed/cancelled. |
void |
setDisposable (Disposable d)
Sets a Disposable on this emitter; any previous
Disposable
or Cancellable will be disposed/cancelled. |
boolean |
tryOnError (Throwable t)
Attempts to emit the specified
Throwable error if the downstream
hasn't cancelled the sequence or is otherwise terminated, returning false
if the emission is not allowed to happen due to lifecycle restrictions. |
onComplete, onError, onNext void setDisposable(@Nullable Disposable d)
Disposable
or Cancellable will be disposed/cancelled.d - the disposable, null is allowedvoid setCancellable(@Nullable Cancellable c)
Disposable
or Cancellable will be disposed/cancelled.c - the cancellable resource, null is allowedlong requested()
This method is thread-safe.
boolean isCancelled()
Emitter.onError(Throwable), Emitter.onComplete() or a
successful tryOnError(Throwable).
This method is thread-safe.
@NonNull FlowableEmitter<T> serialize()
boolean tryOnError(@NonNull Throwable t)
Throwable error if the downstream
hasn't cancelled the sequence or is otherwise terminated, returning false
if the emission is not allowed to happen due to lifecycle restrictions.
Unlike Emitter.onError(Throwable), the RxJavaPlugins.onError is not called
if the error could not be delivered.
History: 2.1.1 - experimental
t - the throwable error to signal if possible