blob: 7ba6066917aeb66b9b8c632e9cc23c1699fcdad4 [file] [log] [blame]
import { Subject } from '../Subject';
import { Subscription } from '../Subscription';
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 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>
*
* <img src="./img/windowToggle.png" width="100%">
*
* 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 <caption>Every other second, emit the click events from the next 500ms</caption>
* var clicks = Rx.Observable.fromEvent(document, 'click');
* var openings = Rx.Observable.interval(1000);
* var result = clicks.windowToggle(openings, i =>
* i % 2 ? Rx.Observable.interval(500) : Rx.Observable.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(openings, closingSelector) {
return (source) => source.lift(new WindowToggleOperator(openings, closingSelector));
}
class WindowToggleOperator {
constructor(openings, closingSelector) {
this.openings = openings;
this.closingSelector = closingSelector;
}
call(subscriber, source) {
return source.subscribe(new WindowToggleSubscriber(subscriber, this.openings, this.closingSelector));
}
}
/**
* We need this JSDoc comment for affecting ESDoc.
* @ignore
* @extends {Ignored}
*/
class WindowToggleSubscriber extends OuterSubscriber {
constructor(destination, openings, closingSelector) {
super(destination);
this.openings = openings;
this.closingSelector = closingSelector;
this.contexts = [];
this.add(this.openSubscription = subscribeToResult(this, openings, openings));
}
_next(value) {
const { contexts } = this;
if (contexts) {
const len = contexts.length;
for (let i = 0; i < len; i++) {
contexts[i].window.next(value);
}
}
}
_error(err) {
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);
}
_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();
}
_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, innerValue, outerIndex, innerIndex, innerSub) {
if (outerValue === this.openings) {
const { closingSelector } = this;
const closingNotifier = tryCatch(closingSelector)(innerValue);
if (closingNotifier === errorObject) {
return this.error(errorObject.e);
}
else {
const window = new Subject();
const subscription = new Subscription();
const context = { window, subscription };
this.contexts.push(context);
const innerSubscription = subscribeToResult(this, closingNotifier, context);
if (innerSubscription.closed) {
this.closeWindow(this.contexts.length - 1);
}
else {
innerSubscription.context = context;
subscription.add(innerSubscription);
}
this.destination.next(window);
}
}
else {
this.closeWindow(this.contexts.indexOf(outerValue));
}
}
notifyError(err) {
this.error(err);
}
notifyComplete(inner) {
if (inner !== this.openSubscription) {
this.closeWindow(this.contexts.indexOf(inner.context));
}
}
closeWindow(index) {
if (index === -1) {
return;
}
const { contexts } = this;
const context = contexts[index];
const { window, subscription } = context;
contexts.splice(index, 1);
window.complete();
subscription.unsubscribe();
}
}
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