computedEager

Category

Reactivity

Export Size

398 B

Last Changed

10 months ago

Alias

eagerComputed

Eager computed without lazy evaluation.

TIP

Note💡: If you are using Vue 3.4+, you can use computed right away. 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.

Demo

source

Lazy Computed

Is over 5: false

Renders: 0

Eager Computed

Is over 5: false

Renders: 0

Count: 0

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

/**
 * 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 ref
 */
export declare function computedEager<T>(
  fn: () => T,
  options?: WatchOptionsBase,
): Readonly<Ref<T>>
export { computedEager as eagerComputed }

Source

Source • Demo • Docs

Contributors

Anthony Fu

briwa

Anthony Fu

Doctorwu

Jonathan Tovar Diaz

wheat

Changelog

v10.7.2 on 1/14/2024

b6d8f - fix: adapt to changes in vue3.4+ (#3689)