[6a3a178] | 1 | import { Operator } from '../Operator';
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| 2 | import { Subscriber } from '../Subscriber';
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| 3 | import { Observable } from '../Observable';
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| 4 | import { OperatorFunction } from '../types';
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| 5 | import { SimpleOuterSubscriber, innerSubscribe, SimpleInnerSubscriber } from '../innerSubscribe';
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| 6 |
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| 7 | /**
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| 8 | * Buffers the source Observable values until `closingNotifier` emits.
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| 9 | *
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| 10 | * <span class="informal">Collects values from the past as an array, and emits
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| 11 | * that array only when another Observable emits.</span>
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| 12 | *
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| 13 | * ![](buffer.png)
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| 14 | *
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| 15 | * Buffers the incoming Observable values until the given `closingNotifier`
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| 16 | * Observable emits a value, at which point it emits the buffer on the output
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| 17 | * Observable and starts a new buffer internally, awaiting the next time
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| 18 | * `closingNotifier` emits.
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| 19 | *
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| 20 | * ## Example
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| 21 | *
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| 22 | * On every click, emit array of most recent interval events
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| 23 | *
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| 24 | * ```ts
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| 25 | * import { fromEvent, interval } from 'rxjs';
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| 26 | * import { buffer } from 'rxjs/operators';
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| 27 | *
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| 28 | * const clicks = fromEvent(document, 'click');
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| 29 | * const intervalEvents = interval(1000);
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| 30 | * const buffered = intervalEvents.pipe(buffer(clicks));
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| 31 | * buffered.subscribe(x => console.log(x));
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| 32 | * ```
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| 33 | *
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| 34 | * @see {@link bufferCount}
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| 35 | * @see {@link bufferTime}
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| 36 | * @see {@link bufferToggle}
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| 37 | * @see {@link bufferWhen}
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| 38 | * @see {@link window}
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| 39 | *
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| 40 | * @param {Observable<any>} closingNotifier An Observable that signals the
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| 41 | * buffer to be emitted on the output Observable.
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| 42 | * @return {Observable<T[]>} An Observable of buffers, which are arrays of
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| 43 | * values.
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| 44 | * @method buffer
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| 45 | * @owner Observable
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| 46 | */
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| 47 | export function buffer<T>(closingNotifier: Observable<any>): OperatorFunction<T, T[]> {
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| 48 | return function bufferOperatorFunction(source: Observable<T>) {
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| 49 | return source.lift(new BufferOperator<T>(closingNotifier));
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| 50 | };
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| 51 | }
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| 52 |
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| 53 | class BufferOperator<T> implements Operator<T, T[]> {
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| 54 |
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| 55 | constructor(private closingNotifier: Observable<any>) {
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| 56 | }
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| 57 |
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| 58 | call(subscriber: Subscriber<T[]>, source: any): any {
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| 59 | return source.subscribe(new BufferSubscriber(subscriber, this.closingNotifier));
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| 60 | }
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| 61 | }
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| 62 |
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| 63 | /**
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| 64 | * We need this JSDoc comment for affecting ESDoc.
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| 65 | * @ignore
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| 66 | * @extends {Ignored}
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| 67 | */
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| 68 | class BufferSubscriber<T> extends SimpleOuterSubscriber<T, any> {
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| 69 | private buffer: T[] = [];
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| 70 |
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| 71 | constructor(destination: Subscriber<T[]>, closingNotifier: Observable<any>) {
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| 72 | super(destination);
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| 73 | this.add(innerSubscribe(closingNotifier, new SimpleInnerSubscriber(this)));
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| 74 | }
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| 75 |
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| 76 | protected _next(value: T) {
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| 77 | this.buffer.push(value);
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| 78 | }
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| 79 |
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| 80 | notifyNext(): void {
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| 81 | const buffer = this.buffer;
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| 82 | this.buffer = [];
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| 83 | this.destination.next!(buffer);
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| 84 | }
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| 85 | }
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