123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081 |
- import { OperatorFunction, ObservableInput } from '../types';
- import { operate } from '../util/lift';
- import { noop } from '../util/noop';
- import { createOperatorSubscriber } from './OperatorSubscriber';
- import { innerFrom } from '../observable/innerFrom';
- /**
- * 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>
- *
- * 
- *
- * Buffers the incoming Observable values until the given `closingNotifier`
- * `ObservableInput` (that internally gets converted to an 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, buffer } from 'rxjs';
- *
- * 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 closingNotifier An `ObservableInput` that signals the
- * buffer to be emitted on the output Observable.
- * @return A function that returns an Observable of buffers, which are arrays
- * of values.
- */
- export function buffer<T>(closingNotifier: ObservableInput<any>): OperatorFunction<T, T[]> {
- return operate((source, subscriber) => {
- // The current buffered values.
- let currentBuffer: T[] = [];
- // Subscribe to our source.
- source.subscribe(
- createOperatorSubscriber(
- subscriber,
- (value) => currentBuffer.push(value),
- () => {
- subscriber.next(currentBuffer);
- subscriber.complete();
- }
- )
- );
- // Subscribe to the closing notifier.
- innerFrom(closingNotifier).subscribe(
- createOperatorSubscriber(
- subscriber,
- () => {
- // Start a new buffer and emit the previous one.
- const b = currentBuffer;
- currentBuffer = [];
- subscriber.next(b);
- },
- noop
- )
- );
- return () => {
- // Ensure buffered values are released on finalization.
- currentBuffer = null!;
- };
- });
- }
|