| import { Subject } from '../Subject'; |
| import { tryCatch } from '../util/tryCatch'; |
| import { errorObject } from '../util/errorObject'; |
| import { OuterSubscriber } from '../OuterSubscriber'; |
| import { subscribeToResult } from '../util/subscribeToResult'; |
| /** |
| * 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> |
| * |
| * <img src="./img/windowWhen.png" width="100%"> |
| * |
| * 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 <caption>Emit only the first two clicks events in every window of [1-5] random seconds</caption> |
| * var clicks = Rx.Observable.fromEvent(document, 'click'); |
| * var result = clicks |
| * .windowWhen(() => Rx.Observable.interval(1000 + Math.random() * 4000)) |
| * .map(win => win.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 function windowWhen(closingSelector) { |
| return function windowWhenOperatorFunction(source) { |
| return source.lift(new WindowOperator(closingSelector)); |
| }; |
| } |
| class WindowOperator { |
| constructor(closingSelector) { |
| this.closingSelector = closingSelector; |
| } |
| call(subscriber, source) { |
| return source.subscribe(new WindowSubscriber(subscriber, this.closingSelector)); |
| } |
| } |
| /** |
| * We need this JSDoc comment for affecting ESDoc. |
| * @ignore |
| * @extends {Ignored} |
| */ |
| class WindowSubscriber extends OuterSubscriber { |
| constructor(destination, closingSelector) { |
| super(destination); |
| this.destination = destination; |
| this.closingSelector = closingSelector; |
| this.openWindow(); |
| } |
| notifyNext(outerValue, innerValue, outerIndex, innerIndex, innerSub) { |
| this.openWindow(innerSub); |
| } |
| notifyError(error, innerSub) { |
| this._error(error); |
| } |
| notifyComplete(innerSub) { |
| this.openWindow(innerSub); |
| } |
| _next(value) { |
| this.window.next(value); |
| } |
| _error(err) { |
| this.window.error(err); |
| this.destination.error(err); |
| this.unsubscribeClosingNotification(); |
| } |
| _complete() { |
| this.window.complete(); |
| this.destination.complete(); |
| this.unsubscribeClosingNotification(); |
| } |
| unsubscribeClosingNotification() { |
| if (this.closingNotification) { |
| this.closingNotification.unsubscribe(); |
| } |
| } |
| openWindow(innerSub = null) { |
| if (innerSub) { |
| this.remove(innerSub); |
| innerSub.unsubscribe(); |
| } |
| const prevWindow = this.window; |
| if (prevWindow) { |
| prevWindow.complete(); |
| } |
| const window = this.window = new Subject(); |
| this.destination.next(window); |
| const closingNotifier = tryCatch(this.closingSelector)(); |
| if (closingNotifier === errorObject) { |
| const err = errorObject.e; |
| this.destination.error(err); |
| this.window.error(err); |
| } |
| else { |
| this.add(this.closingNotification = subscribeToResult(this, closingNotifier)); |
| } |
| } |
| } |
| //# sourceMappingURL=windowWhen.js.map |