watchIgnorable

类别

Watch

导出大小

410 B

最近修改

2 days ago

别名

ignorableWatch

可忽略的监视

🌐 Ignorable watch

示例

源代码在线运行

Value: 0

Log

用法

🌐 Usage

扩展的 watch 返回额外的 ignoreUpdates(updater) 和 ignorePrevAsyncUpdates()，以忽略对源的特定更新。

🌐 Extended watch that returns extra ignoreUpdates(updater) and ignorePrevAsyncUpdates() to ignore particular updates to the source.

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() // 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!

WatchOptionFlush 时间

🌐 WatchOptionFlush timing

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() 将不会起作用，因为观察者会在每次源更新后立即触发。它仍然为同步刷新提供，以便代码可以更加通用。

🌐 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 { 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() // 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!

推荐读物

🌐 Recommended Readings

• 可忽略监视 - 由 @patak-dev 制作