wishthis/node_modules/rxjs/internal/operators/windowWhen.d.ts
2022-01-21 09:28:41 +01:00

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TypeScript

import { Observable } from '../Observable';
import { OperatorFunction } from '../types';
/**
* Branch out the source Observable values as a nested Observable using a
* factory function of closing Observables to determine when to start a new
* window.
*
* <span class="informal">It's like {@link bufferWhen}, but emits a nested
* Observable instead of an array.</span>
*
* ![](windowWhen.png)
*
* Returns an Observable that emits windows of items it collects from the source
* Observable. The output Observable emits connected, non-overlapping windows.
* It emits the current window and opens a new one whenever the Observable
* produced by the specified `closingSelector` function emits an item. The first
* window is opened immediately when subscribing to the output Observable.
*
* ## Example
* Emit only the first two clicks events in every window of [1-5] random seconds
* ```ts
* import { fromEvent, interval } from 'rxjs';
* import { windowWhen, map, mergeAll, take } from 'rxjs/operators';
*
* const clicks = fromEvent(document, 'click');
* const result = clicks.pipe(
* windowWhen(() => interval(1000 + Math.random() * 4000)),
* map(win => win.pipe(take(2))), // each window has at most 2 emissions
* mergeAll() // flatten the Observable-of-Observables
* );
* result.subscribe(x => console.log(x));
* ```
*
* @see {@link window}
* @see {@link windowCount}
* @see {@link windowTime}
* @see {@link windowToggle}
* @see {@link bufferWhen}
*
* @param {function(): Observable} closingSelector A function that takes no
* arguments and returns an Observable that signals (on either `next` or
* `complete`) when to close the previous window and start a new one.
* @return {Observable<Observable<T>>} An observable of windows, which in turn
* are Observables.
* @method windowWhen
* @owner Observable
*/
export declare function windowWhen<T>(closingSelector: () => Observable<any>): OperatorFunction<T, Observable<T>>;