rxjs
Version:
Reactive Extensions for modern JavaScript
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TypeScript
import { MonoTypeOperatorFunction, SchedulerLike } from '../types';
/**
* Emits a value from the source Observable, then ignores subsequent source
* values for `duration` milliseconds, then repeats this process.
*
* <span class="informal">Lets a value pass, then ignores source values for the
* next `duration` milliseconds.</span>
*
* 
*
* `throttleTime` emits the source Observable values on the output Observable
* when its internal timer is disabled, and ignores source values when the timer
* is enabled. Initially, the timer is disabled. As soon as the first source
* value arrives, it is forwarded to the output Observable, and then the timer
* is enabled. After `duration` milliseconds (or the time unit determined
* internally by the optional `scheduler`) has passed, the timer is disabled,
* and this process repeats for the next source value. Optionally takes a
* {@link SchedulerLike} for managing timers.
*
* ## Examples
*
* #### Limit click rate
*
* Emit clicks at a rate of at most one click per second
* ```ts
* import { fromEvent } from 'rxjs';
* import { throttleTime } from 'rxjs/operators';
*
* const clicks = fromEvent(document, 'click');
* const result = clicks.pipe(throttleTime(1000));
* result.subscribe(x => console.log(x));
* ```
*
* #### Double Click
*
* The following example only emits clicks which happen within a subsequent
* delay of 400ms of the previous click. This for example can emulate a double
* click. It makes use of the `trailing` parameter of the throttle configuration.
*
* ```ts
* import { fromEvent, asyncScheduler } from 'rxjs';
* import { throttleTime, withLatestFrom } from 'rxjs/operators';
*
* // defaultThottleConfig = { leading: true, trailing: false }
* const throttleConfig = {
* leading: false,
* trailing: true
* }
*
* const click = fromEvent(document, 'click');
* const doubleClick = click.pipe(
* throttleTime(400, asyncScheduler, throttleConfig)
* );
*
* doubleClick.subscribe((throttleValue: Event) => {
* console.log(`Double-clicked! Timestamp: ${throttleValue.timeStamp}`);
* });
* ```
*
* If you enable the `leading` parameter in this example, the output would be the primary click and
* the double click, but restricts additional clicks within 400ms.
*
* @see {@link auditTime}
* @see {@link debounceTime}
* @see {@link delay}
* @see {@link sampleTime}
* @see {@link throttle}
*
* @param duration Time to wait before emitting another value after
* emitting the last value, measured in milliseconds or the time unit determined
* internally by the optional `scheduler`.
* @param scheduler The {@link SchedulerLike} to use for
* managing the timers that handle the throttling. Defaults to {@link asyncScheduler}.
* @param config a configuration object to define `leading` and
* `trailing` behavior. Defaults to `{ leading: true, trailing: false }`.
* @return A function that returns an Observable that performs the throttle
* operation to limit the rate of emissions from the source.
*/
export declare function throttleTime<T>(duration: number, scheduler?: SchedulerLike, config?: import("./throttle").ThrottleConfig): MonoTypeOperatorFunction<T>;
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