watchIgnorable
可忽略的 watch
Demo
用法
扩展的 watch
,返回额外的 ignoreUpdates(updater)
和 ignorePrevAsyncUpdates()
来忽略特定的源更新。
ts
import { watchIgnorable } from '@vueuse/core'
import { nextTick, shallowRef } from 'vue'
const source = shallowRef('foo')
const { stop, ignoreUpdates } = watchIgnorable(
source,
v => console.log(`Changed to ${v}!`),
)
source.value = 'bar'
await nextTick() // 输出: Changed to bar!
ignoreUpdates(() => {
source.value = 'foobar'
})
await nextTick() // (没有任何输出)
source.value = 'hello'
await nextTick() // 输出: Changed to hello!
ignoreUpdates(() => {
source.value = 'ignored'
})
source.value = 'logged'
await nextTick() // 输出: Changed to logged!
刷新时机
watchIgnorable
接受与 watch
相同的选项并使用相同的默认值。 因此,默认情况下该组合式函数使用 flush: 'pre'
。
ignorePrevAsyncUpdates
此功能仅适用于异步刷新 'pre'
和 'post'
。如果使用 flush: 'sync'
,ignorePrevAsyncUpdates()
将不起作用,因为 watch 会在每次源更新后立即触发。它仍然为同步刷新提供,以便代码可以更通用。
ts
import { watchIgnorable } from '@vueuse/core'
import { nextTick, shallowRef } from 'vue'
const source = shallowRef('foo')
const { ignorePrevAsyncUpdates } = watchIgnorable(
source,
v => console.log(`Changed to ${v}!`),
)
source.value = 'bar'
await nextTick() // 输出: Changed to bar!
source.value = 'good'
source.value = 'by'
ignorePrevAsyncUpdates()
await nextTick() // (没有任何输出)
source.value = 'prev'
ignorePrevAsyncUpdates()
source.value = 'after'
await nextTick() // 输出: Changed to after!
推荐阅读
Type Declarations
Show Type Declarations
typescript
export type IgnoredUpdater = (updater: () => void) => void
export interface WatchIgnorableReturn {
ignoreUpdates: IgnoredUpdater
ignorePrevAsyncUpdates: () => void
stop: WatchStopHandle
}
export declare function watchIgnorable<
T extends Readonly<WatchSource<unknown>[]>,
Immediate extends Readonly<boolean> = false,
>(
sources: [...T],
cb: WatchCallback<MapSources<T>, MapOldSources<T, Immediate>>,
options?: WatchWithFilterOptions<Immediate>,
): WatchIgnorableReturn
export declare function watchIgnorable<
T,
Immediate extends Readonly<boolean> = false,
>(
source: WatchSource<T>,
cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
options?: WatchWithFilterOptions<Immediate>,
): WatchIgnorableReturn
export declare function watchIgnorable<
T extends object,
Immediate extends Readonly<boolean> = false,
>(
source: T,
cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
options?: WatchWithFilterOptions<Immediate>,
): WatchIgnorableReturn
export { watchIgnorable as ignorableWatch }