| 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>>; |