watchDebounced

Debounced watch. The callback will only be invoked after the source stops changing for the specified duration.

Usage

Similar to watch, but offering extra options debounce and maxWait which will be applied to the callback function.

import { watchDebounced } from '@vueuse/core'

watchDebounced(
  source,
  () => { console.log('changed!') },
  { debounce: 500, maxWait: 1000 },
)

Options

Option	Type	Default	Description
`debounce`	`MaybeRefOrGetter<number>`	`0`	Debounce delay in ms (can be reactive)
`maxWait`	`MaybeRefOrGetter<number>`	—	Maximum wait time before forced invocation

All standard watch options (deep, immediate, flush, etc.) are also supported.

Reactive Debounce Time

The debounce time can be reactive:

import { watchDebounced } from '@vueuse/core'

const debounceMs = ref(500)

watchDebounced(
  source,
  () => { console.log('changed!') },
  { debounce: debounceMs },
)

// Later, change the debounce time
debounceMs.value = 1000

How It Works

It's essentially a shorthand for the following code:

import { debounceFilter, watchWithFilter } from '@vueuse/core'

watchWithFilter(
  source,
  () => { console.log('changed!') },
  {
    eventFilter: debounceFilter(500, { maxWait: 1000 }),
  },
)

Type Declarations

export interface WatchDebouncedOptions<Immediate>
  extends WatchOptions<Immediate>, DebounceFilterOptions {
  debounce?: MaybeRefOrGetter<number>
}
export declare function watchDebounced<
  T,
  Immediate extends Readonly<boolean> = false,
>(
  source: WatchSource<T>,
  cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
  options?: WatchDebouncedOptions<Immediate>,
): WatchHandle
export declare function watchDebounced<
  T extends Readonly<MultiWatchSources>,
  Immediate extends Readonly<boolean> = false,
>(
  sources: [...T],
  cb: WatchCallback<MapSources<T>, MapOldSources<T, Immediate>>,
  options?: WatchDebouncedOptions<Immediate>,
): WatchHandle
export declare function watchDebounced<
  T extends object,
  Immediate extends Readonly<boolean> = false,
>(
  source: T,
  cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
  options?: WatchDebouncedOptions<Immediate>,
): WatchHandle
/** @deprecated use `watchDebounced` instead */
export declare const debouncedWatch: typeof watchDebounced