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- 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
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