| import { Operator } from '../Operator'; |
| import { Subscriber } from '../Subscriber'; |
| import { Observable } from '../Observable'; |
| import { OuterSubscriber } from '../OuterSubscriber'; |
| import { InnerSubscriber } from '../InnerSubscriber'; |
| import { subscribeToResult } from '../util/subscribeToResult'; |
| import { OperatorFunction } from '../types'; |
| |
| /** |
| * Buffers the source Observable values until `closingNotifier` emits. |
| * |
| * <span class="informal">Collects values from the past as an array, and emits |
| * that array only when another Observable emits.</span> |
| * |
| * ![](content/img/buffer.png) |
| * |
| * Buffers the incoming Observable values until the given `closingNotifier` |
| * Observable emits a value, at which point it emits the buffer on the output |
| * Observable and starts a new buffer internally, awaiting the next time |
| * `closingNotifier` emits. |
| * |
| * ## Example |
| * |
| * On every click, emit array of most recent interval events |
| * |
| * ```ts |
| * import { fromEvent, interval } from 'rxjs'; |
| * import { buffer } from 'rxjs/operators'; |
| * |
| * const clicks = fromEvent(document, 'click'); |
| * const intervalEvents = interval(1000); |
| * const buffered = intervalEvents.pipe(buffer(clicks)); |
| * buffered.subscribe(x => console.log(x)); |
| * ``` |
| * |
| * @see {@link bufferCount} |
| * @see {@link bufferTime} |
| * @see {@link bufferToggle} |
| * @see {@link bufferWhen} |
| * @see {@link window} |
| * |
| * @param {Observable<any>} closingNotifier An Observable that signals the |
| * buffer to be emitted on the output Observable. |
| * @return {Observable<T[]>} An Observable of buffers, which are arrays of |
| * values. |
| * @method buffer |
| * @owner Observable |
| */ |
| export function buffer<T>(closingNotifier: Observable<any>): OperatorFunction<T, T[]> { |
| return function bufferOperatorFunction(source: Observable<T>) { |
| return source.lift(new BufferOperator<T>(closingNotifier)); |
| }; |
| } |
| |
| class BufferOperator<T> implements Operator<T, T[]> { |
| |
| constructor(private closingNotifier: Observable<any>) { |
| } |
| |
| call(subscriber: Subscriber<T[]>, source: any): any { |
| return source.subscribe(new BufferSubscriber(subscriber, this.closingNotifier)); |
| } |
| } |
| |
| /** |
| * We need this JSDoc comment for affecting ESDoc. |
| * @ignore |
| * @extends {Ignored} |
| */ |
| class BufferSubscriber<T> extends OuterSubscriber<T, any> { |
| private buffer: T[] = []; |
| |
| constructor(destination: Subscriber<T[]>, closingNotifier: Observable<any>) { |
| super(destination); |
| this.add(subscribeToResult(this, closingNotifier)); |
| } |
| |
| protected _next(value: T) { |
| this.buffer.push(value); |
| } |
| |
| notifyNext(outerValue: T, innerValue: any, |
| outerIndex: number, innerIndex: number, |
| innerSub: InnerSubscriber<T, any>): void { |
| const buffer = this.buffer; |
| this.buffer = []; |
| this.destination.next(buffer); |
| } |
| } |