45 lines
1.8 KiB
TypeScript
45 lines
1.8 KiB
TypeScript
|
import { MonoTypeOperatorFunction, SchedulerLike } from '../types';
|
||
|
/**
|
||
|
* Emits the most recently emitted value from the source Observable within
|
||
|
* periodic time intervals.
|
||
|
*
|
||
|
* <span class="informal">Samples the source Observable at periodic time
|
||
|
* intervals, emitting what it samples.</span>
|
||
|
*
|
||
|
* ![](sampleTime.png)
|
||
|
*
|
||
|
* `sampleTime` periodically looks at the source Observable and emits whichever
|
||
|
* value it has most recently emitted since the previous sampling, unless the
|
||
|
* source has not emitted anything since the previous sampling. The sampling
|
||
|
* happens periodically in time every `period` milliseconds (or the time unit
|
||
|
* defined by the optional `scheduler` argument). The sampling starts as soon as
|
||
|
* the output Observable is subscribed.
|
||
|
*
|
||
|
* ## Example
|
||
|
* Every second, emit the most recent click at most once
|
||
|
* ```ts
|
||
|
* import { fromEvent } from 'rxjs';
|
||
|
* import { sampleTime } from 'rxjs/operators';
|
||
|
*
|
||
|
* const clicks = fromEvent(document, 'click');
|
||
|
* const result = clicks.pipe(sampleTime(1000));
|
||
|
* result.subscribe(x => console.log(x));
|
||
|
* ```
|
||
|
*
|
||
|
* @see {@link auditTime}
|
||
|
* @see {@link debounceTime}
|
||
|
* @see {@link delay}
|
||
|
* @see {@link sample}
|
||
|
* @see {@link throttleTime}
|
||
|
*
|
||
|
* @param {number} period The sampling period expressed in milliseconds or the
|
||
|
* time unit determined internally by the optional `scheduler`.
|
||
|
* @param {SchedulerLike} [scheduler=async] The {@link SchedulerLike} to use for
|
||
|
* managing the timers that handle the sampling.
|
||
|
* @return {Observable<T>} An Observable that emits the results of sampling the
|
||
|
* values emitted by the source Observable at the specified time interval.
|
||
|
* @method sampleTime
|
||
|
* @owner Observable
|
||
|
*/
|
||
|
export declare function sampleTime<T>(period: number, scheduler?: SchedulerLike): MonoTypeOperatorFunction<T>;
|