Class DelayWhenOperator

Namespace

RxSharp.Operators

Assembly

RxSharp.dll

Implements the DelayWhen operator. Mirrors rxjs's delayWhen.

public static class DelayWhenOperator

Inheritance

System.Object

DelayWhenOperator

Methods

DelayWhen<T, TDuration>(Observable<T>, Func<T, Observable<TDuration>>)

Delays each value from source until the "duration" observable produced for it by delayDurationSelector emits its first value.

public static Observable<T> DelayWhen<T, TDuration>(this Observable<T> source, Func<T, Observable<TDuration>> delayDurationSelector)

Parameters

source Observable<T>

The source observable whose values are delayed.

delayDurationSelector Func<T, Observable<TDuration>>

A function that, given a source value, returns an observable whose first emission signals that the value may now be forwarded.

Returns

Observable<T>

An observable of the source values, each released once its corresponding duration observable emits.

Type Parameters

T

The element type of the source observable.

TDuration

The element type of the per-value "duration" observable; only used to detect its first emission; the actual value carried is never inspected.

Remarks

Equivalent to the indexed overload with the index ignored. See its remarks for full behavior.

DelayWhen<T, TDuration>(Observable<T>, Func<T, int, Observable<TDuration>>)

Delays each value from source until the "duration" observable produced for it by delayDurationSelector emits its first value.

public static Observable<T> DelayWhen<T, TDuration>(this Observable<T> source, Func<T, int, Observable<TDuration>> delayDurationSelector)

Parameters

source Observable<T>

The source observable whose values are delayed.

delayDurationSelector Func<T, int, Observable<TDuration>>

A function that, given a source value and its index, returns an observable whose first emission signals that the value may now be forwarded.

Returns

Observable<T>

An observable of the source values, each released once its corresponding duration observable emits.

Type Parameters

T

The element type of the source observable.

TDuration

The element type of the per-value "duration" observable; only used to detect its first emission; the actual value carried is never inspected.

Remarks

delayDurationSelector is called with each source value and its zero-based index; the duration observable it returns is subscribed to immediately, but only its first emission (via an internal Take(1)) actually releases the corresponding source value downstream. If a duration observable completes without ever emitting, the source value it was paired with is silently dropped — it never reaches the subscriber. Because durations are handled with unbounded concurrency (via MergeMap), values can be released out of the order their durations were scheduled if a later duration fires before an earlier one — this operator does not preserve source order the way Delay does. If delayDurationSelector throws, or a duration observable errors, the error is forwarded via OnError.