You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
82 lines
3.2 KiB
82 lines
3.2 KiB
import { ThrottleConfig } from './throttle';
|
|
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.png)
|
|
*
|
|
* `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 {number} 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 {SchedulerLike} [scheduler=async] The {@link SchedulerLike} to use for
|
|
* managing the timers that handle the throttling.
|
|
* @param {Object} config a configuration object to define `leading` and
|
|
* `trailing` behavior. Defaults to `{ leading: true, trailing: false }`.
|
|
* @return {Observable<T>} An Observable that performs the throttle operation to
|
|
* limit the rate of emissions from the source.
|
|
* @method throttleTime
|
|
* @owner Observable
|
|
*/
|
|
export declare function throttleTime<T>(duration: number, scheduler?: SchedulerLike, config?: ThrottleConfig): MonoTypeOperatorFunction<T>;
|
|
|