uk.co.strangeskies.observable

Class PassthroughObserver<T,U>

java.lang.Object

uk.co.strangeskies.observable.PassthroughObserver<T,U>

Type Parameters:

T - The message type of the upstream observable

U - The message type of the downstream observer

All Implemented Interfaces:

Observer<T>

Direct Known Subclasses:

BackpressureReducingObserver, DropWhileObserver, FilteringObserver, FlatMappingObserver, MappingObserver, MaterializingObserver, ReferenceObserver, ReferenceOwnedObserver, RepeatingObserver, RetryingObserver, SafeObserver, SynchronizedObserver, TakeWhileObserver

public abstract class PassthroughObserver<T,U>
extends java.lang.Object
implements Observer<T>

This is a helper class for implementing passive observables.

A passive observable is one which does not maintain a set of observations or manage its own events, instead deferring to one or more upstream observables. When an observer subscribes to a passive observable, typically the observer is decorated, and the decorator is then subscribed to the parents. This way the decorator can modify, inspect, or filter events as appropriate before passing them back through to the original observer.

This class is a partial implementation of such a decorator.

Constructor Summary

Constructors

Constructor and Description
PassthroughObserver(Observer<? super U> downstreamObserver)
PassthroughObserver(java.util.function.Supplier<Observer<? super U>> downstreamObserver)

Method Summary

Modifier and Type	Method and Description
Observer<? super U>	getDownstreamObserver()
Observation	getObservation()
protected void	initializeObservation(Observation observation)
void	onComplete()
void	onFail(java.lang.Throwable t)
abstract void	onNext(T message) The method which will receive notification from an Observable.
void	onObserve(Observation observation)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface uk.co.strangeskies.observable.Observer

onCompletion, onFailure, onObservation, singleUse

Constructor Detail

PassthroughObserver

public PassthroughObserver(Observer<? super U> downstreamObserver)

PassthroughObserver

public PassthroughObserver(java.util.function.Supplier<Observer<? super U>> downstreamObserver)

Method Detail

getDownstreamObserver

public Observer<? super U> getDownstreamObserver()

getObservation

public Observation getObservation()

onNext

public abstract void onNext(T message)

Description copied from interface: Observer

The method which will receive notification from an Observable.

Specified by:

onNext in interface Observer<T>

Parameters:

message - the message object instance

initializeObservation

protected void initializeObservation(Observation observation)

onObserve

public void onObserve(Observation observation)

Specified by:

onObserve in interface Observer<T>

onComplete

public void onComplete()

Specified by:

onComplete in interface Observer<T>

onFail

public void onFail(java.lang.Throwable t)

Specified by:

onFail in interface Observer<T>