API / rxjs/operators

throttleTime

Emits a value from the source Observable, then ignores subsequent source values for duration milliseconds, then repeats this process.

throttleTime<T>(duration: number, scheduler: SchedulerLike = async, config: ThrottleConfig = defaultThrottleConfig): MonoTypeOperatorFunction<T>

Parameters

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.
scheduler

Optional. Default is async.

The SchedulerLike to use for managing the timers that handle the throttling.
config

Optional. Default is defaultThrottleConfig.

a configuration object to define leading and trailing behavior. Defaults to { leading: true, trailing: false }.

Returns

MonoTypeOperatorFunction<T>: An Observable that performs the throttle operation to limit the rate of emissions from the source.

Description

Lets a value pass, then ignores source values for the next duration milliseconds.

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 SchedulerLike for managing timers.

Example

Emit clicks at a rate of at most one click per second

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));

See Also