computedWithControl

類別

響應性

匯出大小

267 B

上次變更

3 週前

別名

controlledComputed

相關

refWithControl

明確定義 computed 的依賴項。

用法

TypeScript

import { computedWithControl } from '@vueuse/core'

const source = ref('foo')
const counter = ref(0)

const computedRef = computedWithControl(
  () => source.value, // watch source, same as `watch`
  () => counter.value, // computed getter, same as `computed`
)

import { computedWithControl } from '@vueuse/core'
const source = ref('foo')
const counter = ref(0)
const computedRef = computedWithControl(
  () => source.value, // watch source, same as `watch`
  () => counter.value,
)

這樣一來，counter 的變更不會觸發 computedRef 更新，但 source ref 會。

console.log(computedRef.value) // 0

counter.value += 1

console.log(computedRef.value) // 0

source.value = 'bar'

console.log(computedRef.value) // 1

手動觸發

您也可以透過以下方式手動觸發 computed 的更新

const computedRef = computedWithControl(
  () => source.value,
  () => counter.value,
)

computedRef.trigger()

警告

手動觸發僅適用於 Vue 3

類型宣告

typescript

export interface ComputedWithControlRefExtra {
  /**
   * Force update the computed value.
   */
  trigger: () => void
}
export interface ComputedRefWithControl<T>
  extends ComputedRef<T>,
    ComputedWithControlRefExtra {}
export interface WritableComputedRefWithControl<T>
  extends WritableComputedRef<T>,
    ComputedWithControlRefExtra {}
export declare function computedWithControl<T, S>(
  source: WatchSource<S> | WatchSource<S>[],
  fn: ComputedGetter<T>,
): ComputedRefWithControl<T>
export declare function computedWithControl<T, S>(
  source: WatchSource<S> | WatchSource<S>[],
  fn: WritableComputedOptions<T>,
): WritableComputedRefWithControl<T>
export { computedWithControl as controlledComputed }