blob: 3e5ed184b17919039a9b238748d3c4465650328b [file] [log] [blame]
import { Observable } from '../Observable';
import { OperatorFunction } from '../types';
/**
* Branch out the source Observable values as a nested Observable with each
* nested Observable emitting at most `windowSize` values.
*
* <span class="informal">It's like {@link bufferCount}, but emits a nested
* Observable instead of an array.</span>
*
* ![](windowCount.png)
*
* Returns an Observable that emits windows of items it collects from the source
* Observable. The output Observable emits windows every `startWindowEvery`
* items, each containing no more than `windowSize` items. When the source
* Observable completes or encounters an error, the output Observable emits
* the current window and propagates the notification from the source
* Observable. If `startWindowEvery` is not provided, then new windows are
* started immediately at the start of the source and when each window completes
* with size `windowSize`.
*
* ## Examples
* Ignore every 3rd click event, starting from the first one
* ```ts
* import { fromEvent } from 'rxjs';
* import { windowCount, map, mergeAll, skip } from 'rxjs/operators';
*
* const clicks = fromEvent(document, 'click');
* const result = clicks.pipe(
* windowCount(3),
* map(win => win.pipe(skip(1))), // skip first of every 3 clicks
* mergeAll() // flatten the Observable-of-Observables
* );
* result.subscribe(x => console.log(x));
* ```
*
* Ignore every 3rd click event, starting from the third one
* ```ts
* import { fromEvent } from 'rxjs';
* import { windowCount, mergeAll } from 'rxjs/operators';
*
* const clicks = fromEvent(document, 'click');
* const result = clicks.pipe(
* windowCount(2, 3),
* mergeAll(), // flatten the Observable-of-Observables
* );
* result.subscribe(x => console.log(x));
* ```
*
* @see {@link window}
* @see {@link windowTime}
* @see {@link windowToggle}
* @see {@link windowWhen}
* @see {@link bufferCount}
*
* @param {number} windowSize The maximum number of values emitted by each
* window.
* @param {number} [startWindowEvery] Interval at which to start a new window.
* For example if `startWindowEvery` is `2`, then a new window will be started
* on every other value from the source. A new window is started at the
* beginning of the source by default.
* @return {Observable<Observable<T>>} An Observable of windows, which in turn
* are Observable of values.
* @method windowCount
* @owner Observable
*/
export declare function windowCount<T>(windowSize: number, startWindowEvery?: number): OperatorFunction<T, Observable<T>>;