blob: 3ef496bdd1989d202b3c40f6fed0fc56e2a61a86 [file] [log] [blame]
import { MonoTypeOperatorFunction, SubscribableOrPromise } from '../types';
/**
* Emits a value from the source Observable only after a particular time span
* determined by another Observable has passed without another source emission.
*
* <span class="informal">It's like {@link debounceTime}, but the time span of
* emission silence is determined by a second Observable.</span>
*
* ![](debounce.png)
*
* `debounce` delays values emitted by the source Observable, but drops previous
* pending delayed emissions if a new value arrives on the source Observable.
* This operator keeps track of the most recent value from the source
* Observable, and spawns a duration Observable by calling the
* `durationSelector` function. The value is emitted only when the duration
* Observable emits a value or completes, and if no other value was emitted on
* the source Observable since the duration Observable was spawned. If a new
* value appears before the duration Observable emits, the previous value will
* be dropped and will not be emitted on the output Observable.
*
* Like {@link debounceTime}, this is a rate-limiting operator, and also a
* delay-like operator since output emissions do not necessarily occur at the
* same time as they did on the source Observable.
*
* ## Example
* Emit the most recent click after a burst of clicks
* ```ts
* import { fromEvent, interval } from 'rxjs';
* import { debounce } from 'rxjs/operators';
*
* const clicks = fromEvent(document, 'click');
* const result = clicks.pipe(debounce(() => interval(1000)));
* result.subscribe(x => console.log(x));
* ```
*
* @see {@link audit}
* @see {@link debounceTime}
* @see {@link delayWhen}
* @see {@link throttle}
*
* @param {function(value: T): SubscribableOrPromise} durationSelector A function
* that receives a value from the source Observable, for computing the timeout
* duration for each source value, returned as an Observable or a Promise.
* @return {Observable} An Observable that delays the emissions of the source
* Observable by the specified duration Observable returned by
* `durationSelector`, and may drop some values if they occur too frequently.
* @method debounce
* @owner Observable
*/
export declare function debounce<T>(durationSelector: (value: T) => SubscribableOrPromise<any>): MonoTypeOperatorFunction<T>;