useCached

类别

Utilities

导出体积

199 B

上次更改

4 days ago

使用自定义比较器缓存一个 ref。

比较器签名为 (newSourceValue, cachedValue) => boolean。当它返回 true 时，缓存保持不变。当它返回 false 时，缓存会更新为新的源值。

示例

源码 playground (beta)

Value: 42

Extra: 0

Cached Value: 42

Cached Extra: 0

Temp Value:

Local Extra:

使用

TypeScript

import { useCached
 } from '@vueuse/core'
import { shallowRef
 } from 'vue'

interface Data {
  value
: number
  extra
: number
}

const source
 = shallowRef
<Data>({ value
: 42, extra
: 0 })
const cached
 = useCached
(source
, (newSourceValue
, cachedValue
) => newSourceValue
.value
 === cachedValue
.value
)

source
.value
 = {
  value
: 42,
  extra
: 1,
}

console
.log
(cached
.value
) // { value: 42, extra: 0 }

source
.value
 = {
  value
: 43,
  extra
: 1,
}

console
.log
(cached
.value
) // { value: 43, extra: 1 }

import { useCached } from '@vueuse/core'
import { shallowRef } from 'vue'
const source = shallowRef({ value: 42, extra: 0 })
const cached = useCached(
  source,
  (newSourceValue, cachedValue) => newSourceValue.value === cachedValue.value,
)
source.value = {
  value: 42,
  extra: 1,
}
console.log(cached.value) // { value: 42, extra: 0 }
source.value = {
  value: 43,
  extra: 1,
}
console.log(cached.value) // { value: 43, extra: 1 }

类型声明

export interface UseCachedOptions
<D
 extends boolean = true>
  extends ConfigurableDeepRefs<D
>, WatchOptions {}
export declare function useCached
<T
, D
 extends boolean = true>(
  refValue
: Ref
<T
>,
  comparator
?: (newSourceValue
: T
, cachedValue
: T
) => boolean,
  options
?: UseCachedOptions
<D
>,
): UseCachedReturn
<T
, D
>
export type UseCachedReturn
<
  T
 = any,
  D
 extends boolean = true,
> = ShallowOrDeepRef
<T
, D
>