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. * * Lets a value pass, then ignores source values for the * next `duration` milliseconds. * * ![](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} An Observable that performs the throttle operation to * limit the rate of emissions from the source. * @method throttleTime * @owner Observable */ export declare function throttleTime(duration: number, scheduler?: SchedulerLike, config?: ThrottleConfig): MonoTypeOperatorFunction;