skills/vueuse-functions/references/refThrottled.md
Throttle changing of a ref value.
import { refThrottled } from '@vueuse/core'
import { shallowRef } from 'vue'
const input = shallowRef('')
const throttled = refThrottled(input, 1000)
An example with object ref.
import { refThrottled } from '@vueuse/core'
import { shallowRef } from 'vue'
const data = shallowRef({
count: 0,
name: 'foo',
})
const throttled = refThrottled(data, 1000)
data.value = { count: 1, name: 'foo' }
console.log(throttled.value) // { count: 1, name: 'foo' } (immediate)
data.value = { count: 2, name: 'bar' }
data.value = { count: 3, name: 'baz' }
data.value = { count: 4, name: 'qux' }
console.log(throttled.value) // { count: 1, name: 'foo' } (still first value)
// After 1000ms, next change will be applied
await sleep(1100)
data.value = { count: 5, name: 'final' }
await nextTick()
console.log(throttled.value) // { count: 5, name: 'final' } (updated)
If you don't want to watch trailing changes, set 3rd param false (it's true by default):
import { refThrottled } from '@vueuse/core'
import { shallowRef } from 'vue'
const input = shallowRef('')
const throttled = refThrottled(input, 1000, false)
Allows the callback to be invoked immediately (on the leading edge of the ms timeout). If you don't want this behavior, set the 4th param false (it's true by default):
import { refThrottled } from '@vueuse/core'
import { shallowRef } from 'vue'
const input = shallowRef('')
const throttled = refThrottled(input, 1000, undefined, false)
export type RefThrottledReturn<T = any> = Ref<T>
/**
* Throttle execution of a function. Especially useful for rate limiting
* execution of handlers on events like resize and scroll.
*
* @param value Ref value to be watched with throttle effect
* @param delay A zero-or-greater delay in milliseconds. For event callbacks, values around 100 or 250 (or even higher) are most useful.
* @param trailing if true, update the value again after the delay time is up
* @param leading if true, update the value on the leading edge of the ms timeout
*/
export declare function refThrottled<T = any>(
value: Ref<T>,
delay?: number,
trailing?: boolean,
leading?: boolean,
): RefThrottledReturn<T>
/** @deprecated use `refThrottled` instead */
export declare const throttledRef: typeof refThrottled
/** @deprecated use `refThrottled` instead */
export declare const useThrottle: typeof refThrottled