charging-cabinet/software/h5-uniapp/.agents/skills/vueuse-functions/references/computedEager.md

category, alias

category	alias
Reactivity	eagerComputed

computedEager

Eager computed without lazy evaluation.

::: info This function will be removed in future version. :::

::: tip Note💡: If you are using Vue 3.4+, you can use computed right away, you no longer need this function. In Vue 3.4+, if the computed new value does not change, computed, effect, watch, watchEffect, render dependencies will not be triggered. See: https://github.com/vuejs/core/pull/5912 :::

Learn more at Vue: When a computed property can be the wrong tool.

• Use computed() when you have a complex calculation going on, which can actually profit from caching and lazy evaluation and should only be (re-)calculated if really necessary.
• Use computedEager() when you have a simple operation, with a rarely changing return value – often a boolean.

Usage

import { computedEager } from '@vueuse/core'

const todos = ref([])
const hasOpenTodos = computedEager(() => !!todos.length)

console.log(hasOpenTodos.value) // false
toTodos.value.push({ title: 'Learn Vue' })
console.log(hasOpenTodos.value) // true

Type Declarations

export type ComputedEagerOptions = WatchOptionsBase
export type ComputedEagerReturn<T = any> = Readonly<ShallowRef<T>>
/**
 *
 * @deprecated This function will be removed in future version.
 *
 * Note: If you are using Vue 3.4+, you can straight use computed instead.
 * Because in Vue 3.4+, if computed new value does not change,
 * computed, effect, watch, watchEffect, render dependencies will not be triggered.
 * refer: https://github.com/vuejs/core/pull/5912
 *
 * @param fn effect function
 * @param options WatchOptionsBase
 * @returns readonly shallowRef
 */
export declare function computedEager<T>(
  fn: () => T,
  options?: ComputedEagerOptions,
): ComputedEagerReturn<T>
/** @deprecated use `computedEager` instead */
export declare const eagerComputed: typeof computedEager