This article will talk to you about the basic concepts of combined API, the concept of setup() entry function, and the use of reactive() in the vue3 project. I hope it will be helpful to everyone!
1. Advantages: Easy to learn and use, the location for writing code has been agreed upon.
2. Disadvantages: For large projects, it is not conducive to code reuse, management and maintenance.
3. Explanation: The data and business logic of the same function are scattered in N places in the same file. As the business complexity increases, we need to often use data similar to data() And the back and forth processing in methods
1. Advantages: Data and business logic of the same function can be organized together to facilitate reuse and maintenance.
2. Disadvantages: It requires good code organization and splitting capabilities, and it is not as easy to get started as Vue2.
3. Explanation: Note: In order to allow everyone to transition to the Vue3.0 version better, the writing method of the Vue2.x option API is currently supported.
return To return, you can use directly in the template (generally, setup cannot be an asynchronous function).
<template>
<h1 @click="say()">{{ msg }}</h1>
</template>
<script>
export default {
setup() {
const msg = 'Hello Vue3'
const say = () => {
console.log(msg)
}
return { msg, say }
},
}
</script>
<script>
import { h } from 'vue'
export default {
name: 'App',
setup() {
return () => h('h2', 'Hello Vue3')
},
}
</script>For example, when I have a requirement: click to delete the current row informationView through vueTools, the data is deleted after I click it. But there is no actual rendering on the pageApp.vue
<template> <ul> <li v-for="(item, index) in arr" :key="item" @click="removeItem(index)">{{ item }}</li> </ul> </template> <script> export default { name: 'App', setup() { const arr = ['a', 'b', 'c'] const removeItem = (index) => { arr.splice(index, 1) } return { arr, removeItem, } }, } </script>Copy after login
At this time, use reactive() to wrap the array to make it responsive data. Don’t forget to import
<template>
<ul>
<li v-for="(item, index) in arr" :key="item" @click="removeItem(index)">{{ item }}</li>
</ul>
</template>
<script>
import { reactive } from 'vue'
export default {
name: 'App',
setup() {
const arr = reactive(['a', 'b', 'c'])
const removeItem = (index) => {
arr.splice(index, 1)
}
return {
arr,
removeItem,
}
},
}
</script>
Now the page is responsive, deleted when clicked, and the page is responsive
<template>
<form @submit.prevent="handleSubmit">
<input type="text" v-model="user.id" />
<input type="text" v-model="user.name" />
<input type="submit" />
</form>
<ul>
<li v-for="(item, index) in state.arr" :key="item.id" @click="removeItem(index)">{{ item.name }}</li>
</ul>
</template>
<script>
import { reactive } from 'vue'
export default {
name: 'App',
setup() {
const state = reactive({
arr: [
{
id: 0,
name: 'ifer',
},
{
id: 1,
name: 'elser',
},
{
id: 2,
name: 'xxx',
},
],
})
const removeItem = (index) => {
// 默认是递归监听的，对象里面任何一个数据的变化都是响应式的
state.arr.splice(index, 1)
}
const user = reactive({
id: '',
name: '',
})
const handleSubmit = () => {
state.arr.push({
id: user.id,
name: user.name,
})
user.id = ''
user.name = ''
}
return {
state,
removeItem,
user,
handleSubmit,
}
},
}
</script>
Interpretation of the above code:
Do you have a clearer understanding of the use of setup() now? Let’s simplify our writing method below.
<template>
<form @submit.prevent="handleSubmit">
<input type="text" v-model="user.id" />
<input type="text" v-model="user.name" />
<input type="submit" />
</form>
<ul>
<li v-for="(item, index) in state.arr" :key="item.id" @click="removeItem(index)">{{ item.name }}</li>
</ul>
</template>
<script>
import { reactive } from 'vue'
function useRemoveItem() {
const state = reactive({
arr: [
{
id: 0,
name: 'ifer',
},
{
id: 1,
name: 'elser',
},
{
id: 2,
name: 'xxx',
},
],
})
const removeItem = (index) => {
state.arr.splice(index, 1)
}
return { state, removeItem }
}
function useAddItem(state) {
const user = reactive({
id: '',
name: '',
})
const handleSubmit = () => {
state.arr.push({
id: user.id,
name: user.name,
})
user.id = ''
user.name = ''
}
return {
user,
handleSubmit,
}
}
export default {
name: 'App',
setup() {
const { state, removeItem } = useRemoveItem()
const { user, handleSubmit } = useAddItem(state)
return {
state,
removeItem,
user,
handleSubmit,
}
},
}
</script>将方法抽离出来，用类似于导入的方式进行一个抽离，将数据与方法放在一起，便于我们的统一管理。
App.vue
<template>
<form >
<input type="text" v-model="user.id" />
<input type="text" v-model="user.name" />
<button type="submit" @click.prevent="submit">提交</button>
</form>
<ul>
<li v-for="(item, index) in state.arr" :key="item.id" @click="removeItem(index)">{{ item.name }}</li>
</ul>
</template>
<script>
import {useRemoveItem,handleSubmit} from './hooks'
export default {
name: 'App',
setup() {
const { state, removeItem } = useRemoveItem()
const { user, submit } = handleSubmit(state)
return {
state,removeItem,user,submit
}
},
}
</script>hooks/index.js
import { reactive } from 'vue'
export const useRemoveItem=()=> {
const state= reactive( {
arr: [
{
id: 0,
name: 'ifer',
},
{
id: 1,
name: 'elser',
},
{
id: 2,
name: 'xxx',
},
]
})
const removeItem=(index)=>{
state.arr.splice(index,1)
console.log(state.arr);
}
return { state, removeItem }
}
export const handleSubmit=(state)=>{
const user = reactive({
id: '',
name: '',
})
console.log(1);
const submit = () => {
state.arr.push({
...user
})
user.id = ''
user.name = ''
}
return { user, submit }
}The above is the detailed content of A brief analysis of the use of setup() and reactive() functions in vue3. For more information, please follow other related articles on the PHP Chinese website!
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