Value: 0
Log
ignorableWatch
Ignorable watch
Usage
Extended watch
that returns extra ignoreUpdates(updater)
and ignorePrevAsyncUpdates()
to ignore particular updates to the source.
import { ignorableWatch } from '@vueuse/core'
import { ref, nextTick } from 'vue'
const source = ref('foo')
const { stop, ignoreUpdates } = ignorableWatch(
source,
(v) => console.log(`Changed to ${v}!`),
)
source.value = 'bar'
await nextTick() // logs: Changed to bar!
ignoreUpdates(() => {
source.value = 'foobar'
})
await nextTick() // (nothing happened)
source.value = 'hello'
await nextTick() // logs: Changed to hello!
ignoreUpdates(() => {
source.value = 'ignored'
})
source.value = 'logged'
await nextTick() // logs: Changed to logged!
Flush timing
ignorableWatch
accepts the same options as watch
and uses the same defaults. So, by default the composable works using flush: 'pre'
.
ignorePrevAsyncUpdates
This feature is only for async flush 'pre'
and 'post'
. If flush: 'sync'
is used, ignorePrevAsyncUpdates()
is a no-op as the watch will trigger immediately after each update to the source. It is still provided for sync flush so the code can be more generic.
import { ignorableWatch } from '@vueuse/core'
import { ref, nextTick } from 'vue'
const source = ref('foo')
const { ignorePrevAsyncUpdates } = ignorableWatch(
source,
(v) => console.log(`Changed to ${v}!`),
)
source.value = 'bar'
await nextTick() // logs: Changed to bar!
source.value = 'good'
source.value = 'by'
ignorePrevAsyncUpdates()
await nextTick() // (nothing happened)
source.value = 'prev'
ignorePrevAsyncUpdates()
source.value = 'after'
await nextTick() // logs: Changed to after!
Recommended Readings
Type Declarations
export declare type IgnoredUpdater = (updater: () => void) => void
export interface IgnorableWatchReturn {
ignoreUpdates: IgnoredUpdater
ignorePrevAsyncUpdates: () => void
stop: WatchStopHandle
}
export declare function ignorableWatch<
T extends Readonly<WatchSource<unknown>[]>,
Immediate extends Readonly<boolean> = false
>(
sources: T,
cb: WatchCallback<MapSources<T>, MapOldSources<T, Immediate>>,
options?: WatchWithFilterOptions<Immediate>
): IgnorableWatchReturn
export declare function ignorableWatch<
T,
Immediate extends Readonly<boolean> = false
>(
source: WatchSource<T>,
cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
options?: WatchWithFilterOptions<Immediate>
): IgnorableWatchReturn
export declare function ignorableWatch<
T extends object,
Immediate extends Readonly<boolean> = false
>(
source: T,
cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
options?: WatchWithFilterOptions<Immediate>
): IgnorableWatchReturn