RxJava

rx.operators
Class OperationFirstOrDefault

java.lang.Object
  rx.operators.OperationFirstOrDefault

public final class OperationFirstOrDefault
extends java.lang.Object

Returns an Observable that emits the first item emitted by the source Observable, or a default value if the source emits nothing.

Constructor Summary

OperationFirstOrDefault()

Method Summary

static <T> Observable.OnSubscribeFunc<T>	firstOrDefault(Observable<? extends T> source, Func1<? super T,java.lang.Boolean> predicate, T defaultValue) Returns an Observable that emits the first item emitted by the source Observable that satisfies the given condition, or a default value if the source emits no items that satisfy the given condition.
static <T> Observable.OnSubscribeFunc<T>	firstOrDefault(Observable<? extends T> source, T defaultValue) Returns an Observable that emits the first item emitted by the source Observable, or a default value if the source emits nothing.

Methods inherited from class java.lang.Object

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

Constructor Detail

OperationFirstOrDefault

public OperationFirstOrDefault()

Method Detail

firstOrDefault

public static <T> Observable.OnSubscribeFunc<T> firstOrDefault(Observable<? extends T> source,
                                                               Func1<? super T,java.lang.Boolean> predicate,
                                                               T defaultValue)

Returns an Observable that emits the first item emitted by the source Observable that satisfies the given condition, or a default value if the source emits no items that satisfy the given condition.

Parameters:

source - The source Observable to emit the first item for.

predicate - The condition the emitted source items have to satisfy.

defaultValue - The default value to use whenever the source Observable doesn't emit anything.

Returns:

A subscription function for creating the target Observable.

firstOrDefault

public static <T> Observable.OnSubscribeFunc<T> firstOrDefault(Observable<? extends T> source,
                                                               T defaultValue)

Returns an Observable that emits the first item emitted by the source Observable, or a default value if the source emits nothing.

Parameters:

source - The source Observable to emit the first item for.

defaultValue - The default value to use whenever the source Observable doesn't emit anything.

Returns:

A subscription function for creating the target Observable.