Class WindowWhenOperator

Namespace

RxSharp.Operators

Assembly

RxSharp.dll

The windowWhen operator.

public static class WindowWhenOperator

Inheritance

System.Object

WindowWhenOperator

Methods

WindowWhen<T, TBoundary>(Observable<T>, Func<Observable<TBoundary>>)

Branches out source's values as a nested Observable<T> that closes (completing) and immediately reopens each time the observable returned by closingSelector emits or completes. Mirrors rxjs's windowWhen. The first window opens eagerly at subscription time; closingSelector is invoked again, and its result subscribed to afresh, every time a new window opens.

public static Observable<Observable<T>> WindowWhen<T, TBoundary>(this Observable<T> source, Func<Observable<TBoundary>> closingSelector)

Parameters

source Observable<T>

The source observable.

closingSelector Func<Observable<TBoundary>>

Invoked (with no arguments) each time a window opens; the observable it returns closes that window on its first next or complete notification.

Returns

Observable<Observable<T>>

An observable of windows, each itself an observable of the values collected during its lifetime.

Type Parameters

T

The element type of the source.

TBoundary

The (unused) element type of the closing-notifier observable.

Remarks

Each closing-notifier subscription is torn down as soon as it produces its first signal (next or complete) — built directly via Create<T>(Action<T>?, Action<Exception>?, Action?) assigned to its slot before subscribing (the same pattern Take/First use — see their remarks), rather than a SingleAssignmentDisposable reassigned only after Subscribe returns. This matters here specifically: a closing notifier that emits and then completes synchronously (e.g. Observable.Of(1)) would otherwise reopen the window twice for a single notifier, since both the synchronous next and the following complete would each trigger a reopen before the naive wrapper-reassignment could take effect. Each closing-notifier subscriber is also registered as a child of source's downstream subscriber (via Add(IDisposable)) before it is subscribed — see SubscribeChild<TSource, TResult>(Observable<TSource>, Subscriber<TResult>, Action<TSource>?, Action<Exception>?, Action?) — and removed again as soon as it is superseded by the next cycle's, so a downstream disposal cascades into whichever closing-notifier subscription is currently active instead of only the latest one leaking forever as a dead entry in the downstream subscriber's finalizer list.