主题
watchArray
观察有添加和删除的数组。
¥Watch for an array with additions and removals.
用法
¥Usage
与 watch
类似,但向回调函数提供添加和删除的元素。如果列表已更新为 push
、splice
等,则通过 { deep: true }
。
¥Similar to watch
, but provides the added and removed elements to the callback function. Pass { deep: true }
if the list is updated in place with push
, splice
, etc.
ts
import { watchArray } from '@vueuse/core'
const list = ref([1, 2, 3])
watchArray(list, (newList, oldList, added, removed) => {
console.log(newList) // [1, 2, 3, 4]
console.log(oldList) // [1, 2, 3]
console.log(added) // [4]
console.log(removed) // []
})
onMounted(() => {
list.value = [...list.value, 4]
})
类型声明
typescript
export declare type WatchArrayCallback<V = any, OV = any> = (
value: V,
oldValue: OV,
added: V,
removed: OV,
onCleanup: (cleanupFn: () => void) => void,
) => any
/**
* Watch for an array with additions and removals.
*
* @see https://vueuse.org/watchArray
*/
export declare function watchArray<
T,
Immediate extends Readonly<boolean> = false,
>(
source: WatchSource<T[]> | T[],
cb: WatchArrayCallback<T[], Immediate extends true ? T[] | undefined : T[]>,
options?: WatchOptions<Immediate>,
): WatchHandle