| import { Operator } from '../Operator'; |
| import { Subscriber } from '../Subscriber'; |
| import { Observable } from '../Observable'; |
| import { Subject } from '../Subject'; |
| import { Subscription } from '../Subscription'; |
| import { OuterSubscriber } from '../OuterSubscriber'; |
| import { InnerSubscriber } from '../InnerSubscriber'; |
| import { subscribeToResult } from '../util/subscribeToResult'; |
| import { OperatorFunction } from '../types'; |
| |
| /** |
| * Branch out the source Observable values as a nested Observable starting from |
| * an emission from `openings` and ending when the output of `closingSelector` |
| * emits. |
| * |
| * <span class="informal">It's like {@link bufferToggle}, but emits a nested |
| * Observable instead of an array.</span> |
| * |
| * ![](windowToggle.png) |
| * |
| * Returns an Observable that emits windows of items it collects from the source |
| * Observable. The output Observable emits windows that contain those items |
| * emitted by the source Observable between the time when the `openings` |
| * Observable emits an item and when the Observable returned by |
| * `closingSelector` emits an item. |
| * |
| * ## Example |
| * Every other second, emit the click events from the next 500ms |
| * ```ts |
| * import { fromEvent, interval, EMPTY } from 'rxjs'; |
| * import { windowToggle, mergeAll } from 'rxjs/operators'; |
| * |
| * const clicks = fromEvent(document, 'click'); |
| * const openings = interval(1000); |
| * const result = clicks.pipe( |
| * windowToggle(openings, i => i % 2 ? interval(500) : EMPTY), |
| * mergeAll() |
| * ); |
| * result.subscribe(x => console.log(x)); |
| * ``` |
| * |
| * @see {@link window} |
| * @see {@link windowCount} |
| * @see {@link windowTime} |
| * @see {@link windowWhen} |
| * @see {@link bufferToggle} |
| * |
| * @param {Observable<O>} openings An observable of notifications to start new |
| * windows. |
| * @param {function(value: O): Observable} closingSelector A function that takes |
| * the value emitted by the `openings` observable and returns an Observable, |
| * which, when it emits (either `next` or `complete`), signals that the |
| * associated window should complete. |
| * @return {Observable<Observable<T>>} An observable of windows, which in turn |
| * are Observables. |
| * @method windowToggle |
| * @owner Observable |
| */ |
| export function windowToggle<T, O>(openings: Observable<O>, |
| closingSelector: (openValue: O) => Observable<any>): OperatorFunction<T, Observable<T>> { |
| return (source: Observable<T>) => source.lift(new WindowToggleOperator<T, O>(openings, closingSelector)); |
| } |
| |
| class WindowToggleOperator<T, O> implements Operator<T, Observable<T>> { |
| |
| constructor(private openings: Observable<O>, |
| private closingSelector: (openValue: O) => Observable<any>) { |
| } |
| |
| call(subscriber: Subscriber<Observable<T>>, source: any): any { |
| return source.subscribe(new WindowToggleSubscriber( |
| subscriber, this.openings, this.closingSelector |
| )); |
| } |
| } |
| |
| interface WindowContext<T> { |
| window: Subject<T>; |
| subscription: Subscription; |
| } |
| |
| /** |
| * We need this JSDoc comment for affecting ESDoc. |
| * @ignore |
| * @extends {Ignored} |
| */ |
| class WindowToggleSubscriber<T, O> extends OuterSubscriber<T, any> { |
| private contexts: WindowContext<T>[] = []; |
| private openSubscription: Subscription; |
| |
| constructor(destination: Subscriber<Observable<T>>, |
| private openings: Observable<O>, |
| private closingSelector: (openValue: O) => Observable<any>) { |
| super(destination); |
| this.add(this.openSubscription = subscribeToResult(this, openings, openings as any)); |
| } |
| |
| protected _next(value: T) { |
| const { contexts } = this; |
| if (contexts) { |
| const len = contexts.length; |
| for (let i = 0; i < len; i++) { |
| contexts[i].window.next(value); |
| } |
| } |
| } |
| |
| protected _error(err: any) { |
| |
| const { contexts } = this; |
| this.contexts = null; |
| |
| if (contexts) { |
| const len = contexts.length; |
| let index = -1; |
| |
| while (++index < len) { |
| const context = contexts[index]; |
| context.window.error(err); |
| context.subscription.unsubscribe(); |
| } |
| } |
| |
| super._error(err); |
| } |
| |
| protected _complete() { |
| const { contexts } = this; |
| this.contexts = null; |
| if (contexts) { |
| const len = contexts.length; |
| let index = -1; |
| while (++index < len) { |
| const context = contexts[index]; |
| context.window.complete(); |
| context.subscription.unsubscribe(); |
| } |
| } |
| super._complete(); |
| } |
| |
| /** @deprecated This is an internal implementation detail, do not use. */ |
| _unsubscribe() { |
| const { contexts } = this; |
| this.contexts = null; |
| if (contexts) { |
| const len = contexts.length; |
| let index = -1; |
| while (++index < len) { |
| const context = contexts[index]; |
| context.window.unsubscribe(); |
| context.subscription.unsubscribe(); |
| } |
| } |
| } |
| |
| notifyNext(outerValue: any, innerValue: any, |
| outerIndex: number, innerIndex: number, |
| innerSub: InnerSubscriber<T, any>): void { |
| |
| if (outerValue === this.openings) { |
| let closingNotifier; |
| try { |
| const { closingSelector } = this; |
| closingNotifier = closingSelector(innerValue); |
| } catch (e) { |
| return this.error(e); |
| } |
| |
| const window = new Subject<T>(); |
| const subscription = new Subscription(); |
| const context = { window, subscription }; |
| this.contexts.push(context); |
| const innerSubscription = subscribeToResult(this, closingNotifier, context as any); |
| |
| if (innerSubscription.closed) { |
| this.closeWindow(this.contexts.length - 1); |
| } else { |
| (<any>innerSubscription).context = context; |
| subscription.add(innerSubscription); |
| } |
| |
| this.destination.next(window); |
| } else { |
| this.closeWindow(this.contexts.indexOf(outerValue)); |
| } |
| } |
| |
| notifyError(err: any): void { |
| this.error(err); |
| } |
| |
| notifyComplete(inner: Subscription): void { |
| if (inner !== this.openSubscription) { |
| this.closeWindow(this.contexts.indexOf((<any> inner).context)); |
| } |
| } |
| |
| private closeWindow(index: number): void { |
| if (index === -1) { |
| return; |
| } |
| |
| const { contexts } = this; |
| const context = contexts[index]; |
| const { window, subscription } = context; |
| contexts.splice(index, 1); |
| window.complete(); |
| subscription.unsubscribe(); |
| } |
| } |