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- import { Observable } from '../Observable';
- import { OperatorFunction, ObservableInput } from '../types';
- import { Subject } from '../Subject';
- import { operate } from '../util/lift';
- import { createOperatorSubscriber } from './OperatorSubscriber';
- import { noop } from '../util/noop';
- import { innerFrom } from '../observable/innerFrom';
- /**
- * Branch out the source Observable values as a nested Observable whenever
- * `windowBoundaries` emits.
- *
- * <span class="informal">It's like {@link buffer}, but emits a nested Observable
- * instead of an array.</span>
- *
- * 
- *
- * 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
- * `windowBoundaries` emits an item. `windowBoundaries` can be any type that
- * `ObservableInput` accepts. It internally gets converted to an Observable.
- * Because each window is an Observable, the output is a higher-order Observable.
- *
- * ## Example
- *
- * In every window of 1 second each, emit at most 2 click events
- *
- * ```ts
- * import { fromEvent, interval, window, map, take, mergeAll } from 'rxjs';
- *
- * const clicks = fromEvent(document, 'click');
- * const sec = interval(1000);
- * const result = clicks.pipe(
- * window(sec),
- * map(win => win.pipe(take(2))), // take at most 2 emissions from each window
- * mergeAll() // flatten the Observable-of-Observables
- * );
- * result.subscribe(x => console.log(x));
- * ```
- *
- * @see {@link windowCount}
- * @see {@link windowTime}
- * @see {@link windowToggle}
- * @see {@link windowWhen}
- * @see {@link buffer}
- *
- * @param windowBoundaries An `ObservableInput` that completes the
- * previous window and starts a new window.
- * @return A function that returns an Observable of windows, which are
- * Observables emitting values of the source Observable.
- */
- export function window<T>(windowBoundaries: ObservableInput<any>): OperatorFunction<T, Observable<T>> {
- return operate((source, subscriber) => {
- let windowSubject: Subject<T> = new Subject<T>();
- subscriber.next(windowSubject.asObservable());
- const errorHandler = (err: any) => {
- windowSubject.error(err);
- subscriber.error(err);
- };
- // Subscribe to our source
- source.subscribe(
- createOperatorSubscriber(
- subscriber,
- (value) => windowSubject?.next(value),
- () => {
- windowSubject.complete();
- subscriber.complete();
- },
- errorHandler
- )
- );
- // Subscribe to the window boundaries.
- innerFrom(windowBoundaries).subscribe(
- createOperatorSubscriber(
- subscriber,
- () => {
- windowSubject.complete();
- subscriber.next((windowSubject = new Subject()));
- },
- noop,
- errorHandler
- )
- );
- return () => {
- // Unsubscribing the subject ensures that anyone who has captured
- // a reference to this window that tries to use it after it can
- // no longer get values from the source will get an ObjectUnsubscribedError.
- windowSubject?.unsubscribe();
- windowSubject = null!;
- };
- });
- }
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