| import { Subscription } from '../Subscription'; |
| import { tryCatch } from '../util/tryCatch'; |
| import { errorObject } from '../util/errorObject'; |
| import { OuterSubscriber } from '../OuterSubscriber'; |
| import { subscribeToResult } from '../util/subscribeToResult'; |
| /** |
| * Buffers the source Observable values, using a factory function of closing |
| * Observables to determine when to close, emit, and reset the buffer. |
| * |
| * <span class="informal">Collects values from the past as an array. When it |
| * starts collecting values, it calls a function that returns an Observable that |
| * tells when to close the buffer and restart collecting.</span> |
| * |
| * <img src="./img/bufferWhen.png" width="100%"> |
| * |
| * Opens a buffer immediately, then closes the buffer when the observable |
| * returned by calling `closingSelector` function emits a value. When it closes |
| * the buffer, it immediately opens a new buffer and repeats the process. |
| * |
| * @example <caption>Emit an array of the last clicks every [1-5] random seconds</caption> |
| * var clicks = Rx.Observable.fromEvent(document, 'click'); |
| * var buffered = clicks.bufferWhen(() => |
| * Rx.Observable.interval(1000 + Math.random() * 4000) |
| * ); |
| * buffered.subscribe(x => console.log(x)); |
| * |
| * @see {@link buffer} |
| * @see {@link bufferCount} |
| * @see {@link bufferTime} |
| * @see {@link bufferToggle} |
| * @see {@link windowWhen} |
| * |
| * @param {function(): Observable} closingSelector A function that takes no |
| * arguments and returns an Observable that signals buffer closure. |
| * @return {Observable<T[]>} An observable of arrays of buffered values. |
| * @method bufferWhen |
| * @owner Observable |
| */ |
| export function bufferWhen(closingSelector) { |
| return function (source) { |
| return source.lift(new BufferWhenOperator(closingSelector)); |
| }; |
| } |
| class BufferWhenOperator { |
| constructor(closingSelector) { |
| this.closingSelector = closingSelector; |
| } |
| call(subscriber, source) { |
| return source.subscribe(new BufferWhenSubscriber(subscriber, this.closingSelector)); |
| } |
| } |
| /** |
| * We need this JSDoc comment for affecting ESDoc. |
| * @ignore |
| * @extends {Ignored} |
| */ |
| class BufferWhenSubscriber extends OuterSubscriber { |
| constructor(destination, closingSelector) { |
| super(destination); |
| this.closingSelector = closingSelector; |
| this.subscribing = false; |
| this.openBuffer(); |
| } |
| _next(value) { |
| this.buffer.push(value); |
| } |
| _complete() { |
| const buffer = this.buffer; |
| if (buffer) { |
| this.destination.next(buffer); |
| } |
| super._complete(); |
| } |
| _unsubscribe() { |
| this.buffer = null; |
| this.subscribing = false; |
| } |
| notifyNext(outerValue, innerValue, outerIndex, innerIndex, innerSub) { |
| this.openBuffer(); |
| } |
| notifyComplete() { |
| if (this.subscribing) { |
| this.complete(); |
| } |
| else { |
| this.openBuffer(); |
| } |
| } |
| openBuffer() { |
| let { closingSubscription } = this; |
| if (closingSubscription) { |
| this.remove(closingSubscription); |
| closingSubscription.unsubscribe(); |
| } |
| const buffer = this.buffer; |
| if (this.buffer) { |
| this.destination.next(buffer); |
| } |
| this.buffer = []; |
| const closingNotifier = tryCatch(this.closingSelector)(); |
| if (closingNotifier === errorObject) { |
| this.error(errorObject.e); |
| } |
| else { |
| closingSubscription = new Subscription(); |
| this.closingSubscription = closingSubscription; |
| this.add(closingSubscription); |
| this.subscribing = true; |
| closingSubscription.add(subscribeToResult(this, closingNotifier)); |
| this.subscribing = false; |
| } |
| } |
| } |
| //# sourceMappingURL=bufferWhen.js.map |