hu.akarnokd.rxjava3.expr

Class StatementObservable

java.lang.Object

hu.akarnokd.rxjava3.expr.StatementObservable

public final class StatementObservable
extends Object

Imperative statements expressed as Observable operators.

Method Summary

Modifier and Type	Method and Description
static <T> Observable<T>	doWhile(ObservableSource<? extends T> source, BooleanSupplier postCondition) Return an Observable that re-emits the emissions from the source Observable, and then re-subscribes to the source long as a condition is true.
static <R> Observable<R>	ifThen(BooleanSupplier condition, ObservableSource<? extends R> then) Return an Observable that emits the emissions from a specified Observable if a condition evaluates to true, otherwise return an empty Observable.
static <R> Observable<R>	ifThen(BooleanSupplier condition, ObservableSource<? extends R> then, Observable<? extends R> orElse) Return an Observable that emits the emissions from one specified Observable if a condition evaluates to true, or from another specified Observable otherwise.
static <R> Observable<R>	ifThen(BooleanSupplier condition, ObservableSource<? extends R> then, Scheduler scheduler) Return an Observable that emits the emissions from a specified Observable if a condition evaluates to true, otherwise return an empty Observable that runs on a specified Scheduler.
static <K,R> Observable<R>	switchCase(Supplier<? extends K> caseSelector, Map<? super K,? extends ObservableSource<? extends R>> mapOfCases) Return a particular one of several possible Observables based on a case selector.
static <K,R> Observable<R>	switchCase(Supplier<? extends K> caseSelector, Map<? super K,? extends ObservableSource<? extends R>> mapOfCases, ObservableSource<? extends R> defaultCase) Return a particular one of several possible Observables based on a case selector, or a default Observable if the case selector does not map to a particular one.
static <K,R> Observable<R>	switchCase(Supplier<? extends K> caseSelector, Map<? super K,? extends ObservableSource<? extends R>> mapOfCases, Scheduler scheduler) Return a particular one of several possible Observables based on a case selector and run it on the designated scheduler.
static <T> Observable<T>	whileDo(ObservableSource<? extends T> source, BooleanSupplier preCondition) Return an Observable that re-emits the emissions from the source Observable as long as the condition is true before the first or subsequent subscribe() calls.

Methods inherited from class java.lang.Object

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

Method Detail

switchCase

public static <K,R> Observable<R> switchCase(Supplier<? extends K> caseSelector,
                                             Map<? super K,? extends ObservableSource<? extends R>> mapOfCases)

Return a particular one of several possible Observables based on a case selector.

Type Parameters:

K - the case key type

R - the result value type

Parameters:

caseSelector - the function that produces a case key when an Observer subscribes

mapOfCases - a map that maps a case key to an Observable

Returns:

a particular Observable chosen by key from the map of Observables, or an empty Observable if no Observable matches the key

switchCase

public static <K,R> Observable<R> switchCase(Supplier<? extends K> caseSelector,
                                             Map<? super K,? extends ObservableSource<? extends R>> mapOfCases,
                                             Scheduler scheduler)

Return a particular one of several possible Observables based on a case selector and run it on the designated scheduler.

Type Parameters:

K - the case key type

R - the result value type

Parameters:

caseSelector - the function that produces a case key when an Observer subscribes

mapOfCases - a map that maps a case key to an Observable

scheduler - the scheduler where the empty observable is observed

Returns:

a particular Observable chosen by key from the map of Observables, or an empty Observable if no Observable matches the key, but one that runs on the designated scheduler in either case

switchCase

public static <K,R> Observable<R> switchCase(Supplier<? extends K> caseSelector,
                                             Map<? super K,? extends ObservableSource<? extends R>> mapOfCases,
                                             ObservableSource<? extends R> defaultCase)

Return a particular one of several possible Observables based on a case selector, or a default Observable if the case selector does not map to a particular one.

Type Parameters:

K - the case key type

R - the result value type

Parameters:

caseSelector - the function that produces a case key when an Observer subscribes

mapOfCases - a map that maps a case key to an Observable

defaultCase - the default Observable if the mapOfCases doesn't contain a value for the key returned by the caseSelector

Returns:

a particular Observable chosen by key from the map of Observables, or the default case if no Observable matches the key

doWhile

public static <T> Observable<T> doWhile(ObservableSource<? extends T> source,
                                        BooleanSupplier postCondition)

Return an Observable that re-emits the emissions from the source Observable, and then re-subscribes to the source long as a condition is true.

Type Parameters:

T - the value type

Parameters:

source - the source Observable to work with

postCondition - the post condition to test after the source Observable completes

Returns:

an Observable that replays the emissions from the source Observable, and then continues to replay them so long as the post condition is true

whileDo

public static <T> Observable<T> whileDo(ObservableSource<? extends T> source,
                                        BooleanSupplier preCondition)

Return an Observable that re-emits the emissions from the source Observable as long as the condition is true before the first or subsequent subscribe() calls.

Type Parameters:

T - the value type

Parameters:

source - the source Observable to work with

preCondition - the condition to evaluate before subscribing to or replaying the source Observable

Returns:

an Observable that replays the emissions from the source Observable so long as preCondition is true

ifThen

public static <R> Observable<R> ifThen(BooleanSupplier condition,
                                       ObservableSource<? extends R> then)

Return an Observable that emits the emissions from a specified Observable if a condition evaluates to true, otherwise return an empty Observable.

Type Parameters:

R - the result value type

Parameters:

condition - the condition that decides whether to emit the emissions from the then Observable

then - the Observable sequence to emit to if condition is true

Returns:

an Observable that mimics the then Observable if the condition function evaluates to true, or an empty Observable otherwise

ifThen

public static <R> Observable<R> ifThen(BooleanSupplier condition,
                                       ObservableSource<? extends R> then,
                                       Scheduler scheduler)

Return an Observable that emits the emissions from a specified Observable if a condition evaluates to true, otherwise return an empty Observable that runs on a specified Scheduler.

Type Parameters:

R - the result value type

Parameters:

condition - the condition that decides whether to emit the emissions from the then Observable

then - the Observable sequence to emit to if condition is true

scheduler - the Scheduler on which the empty Observable runs if the in case the condition returns false

Returns:

an Observable that mimics the then Observable if the condition function evaluates to true, or an empty Observable running on the specified Scheduler otherwise

ifThen

public static <R> Observable<R> ifThen(BooleanSupplier condition,
                                       ObservableSource<? extends R> then,
                                       Observable<? extends R> orElse)

Return an Observable that emits the emissions from one specified Observable if a condition evaluates to true, or from another specified Observable otherwise.

Type Parameters:

R - the result value type

Parameters:

condition - the condition that decides which Observable to emit the emissions from

then - the Observable sequence to emit to if condition is true

orElse - the Observable sequence to emit to if condition is false

Returns:

an Observable that mimics either the then or orElse Observables depending on a condition function