Vue CLI ref props mixin plugin scoped
ref
ref被用来给元素或子组件注册引用信息（id的替代者）
- 应用在html标签上获取的是真实DOM元素，应用在组件标签上获取的是组件实例对象vc
- 使用方式
- 打标识：或
- 获取：this.$refs.xxx
<template>
<div>
<h1 v-text="msg" ref="title"></h1>
<button ref="btn" @click="showDOM">点我输出上方的DOM元素</button>
<School ref="sch"/>
</div>
</template>
<script>
import School from './components/School'
export default {
name:'App',
components:{ School },
data() {
return {
msg:'欢迎学习Vue！'
}
},
methods: {
showDOM(){
console.log(this.$refs.title) // 真实DOM元素
console.log(this.$refs.btn) // 真实DOM元素
console.log(this.$refs.sch) // School组件的实例对象（vc）
}
},
}
</script>
props
props让组件接收外部传过来的数据
-
传递数据这里age前加:，通过v-bind使得里面的18是数字
-
接收数据
第一种方式（只接收）props:['name', 'age'] 第二种方式（限制类型）props:{name:String, age:Number} 第三种方式（限制类型、限制必要性、指定默认值）
props: {
name: {
type: String, // 类型
required: true,// 必要性
default: 'cess'// 默认值
}
}
备注：props是只读的，Vue底层会监测你对props的修改，如果进行了修改，就会发出警告，若业务需求确实需要修改，那么请复制props的内容到data中，然后去修改data中的数据
App.vue
<template>
<div>
<Student name="李四" sex="女" :age="18"/>
<Student name="王五" sex="男" :age="18"/>
</div>
</template>
<script>
import Student from './components/Student'
export default {
name:'App',
components:{ Student }
}
</script>
Student.vue
<template>
<div>
<h1>{{ msg }}</h1>
<h2>学生姓名：{{ name }}</h2>
<h2>学生性别：{{ sex }}</h2>
<h2>学生年龄：{{ myAge + 1 }}</h2>
<button @click="updateAge">尝试修改收到的年龄</button>
</div>
</template>
<script>
export default {
name: "Student",
data() {
console.log(this);
return {
msg: "我是一个UESTC大学的学生",
myAge: this.age,
};
},
methods: { updateAge() { this.myAge++; }, },
// 简单声明接收
// props:['name','age','sex']
// 接收的同时对数据进行类型限制
// props: {
// name: String,
// age: Number,
// sex: String,
// }
// 接收的同时对数据：进行类型限制+默认值的指定+必要性的限制
props: {
name: {
type: String, //name的类型是字符串
required: true, //name是必要的
},
age: {
type: Number,
default: 99, //默认值
},
sex: {
type: String,
required: true,
},
},
};
</script>
mixin
-
功能：可以把多个组件共用的配置提取成一个混入对象
-
使用方式
a.定义混入
const mixin = { data() {....}, methods: {....} .... }b.使用混入
ⅰ全局混入Vue.mixin(xxx) ⅱ局部混入mixins:['xxx']
-
备注
-
组件和混入对象含有同名选项时，这些选项将以恰当的方式进行“合并”，在发生冲突时以组件优先
var mixin = { data: function () { return { message: 'hello', foo: 'abc' } } } new Vue({ mixins: [mixin], data () { return { message: 'goodbye', bar: 'def' } }, created () { console.log(this.$data) // => { message: "goodbye", foo: "abc", bar: "def" } } }) -
同名生命周期钩子将合并为一个数组，因此都将被调用。另外，混入对象的钩子将在组件自身钩子之前调用
var mixin = { created () { console.log('混入对象的钩子被调用') } } new Vue({ mixins: [mixin], created () { console.log('组件钩子被调用') } }) // => "混入对象的钩子被调用" // => "组件钩子被调用"
-
mixin.js
export const hunhe = {
methods: {
showName(){
alert(this.name)
}
},
mounted() {
console.log('你好啊！')
},
}
export const hunhe2 = {
data() {
return {
x:100,
y:200
}
},
}
School.vue
<template>
<div>
<h2 @click="showName">学校名称：{{name}}</h2>
<h2>学校地址：{{address}}</h2>
</div>
</template>
<script>
//引入一个hunhe
import {hunhe,hunhe2} from '../mixin'
export default {
name:'School',
data() {
return {
name:'尚硅谷',
address:'北京',
x:666
}
},
mixins:[hunhe,hunhe2] // 局部混入
}
</script>
Student.vue
<template>
<div>
<h2 @click="showName">学生姓名：{{name}}</h2>
<h2>学生性别：{{sex}}</h2>
</div>
</template>
<script>
import {hunhe,hunhe2} from '../mixin'
export default {
name:'Student',
data() {
return {
name:'张三',
sex:'男'
}
},
mixins:[hunhe,hunhe2] // 局部混入
}
</script>
App.vue
<template>
<div>
<School/>
<hr>
<Student/>
</div>
</template>
<script>
import School from './components/School'
import Student from './components/Student'
export default {
name:'App',
components:{School,Student}
}
</script>
main.js
import Vue from 'vue'
import App from './App.vue'
// import {mixin} from './mixin'
Vue.config.productionTip = false
// Vue.mixin(hunhe) // 全局混合引入
// Vue.mixin(hunhe2) // 全局混合
new Vue({
el:"#app",
render: h => h(App)
})
plugin
- 功能：用于增强Vue
- 本质：包含install方法的一个对象，install的第一个参数是Vue，第二个以后的参数是插件使用者传递的数据
- 定义插件（见下 src/plugin.js）
- 使用插件：Vue.use()
plugin.js
export default {
install(Vue,x,y,z){
console.log(x,y,z)
//全局过滤器
Vue.filter('mySlice', function(value){return value.slice(0,4)})
//定义全局指令
Vue.directive('fbind',{
//指令与元素成功绑定时（一上来）
bind(element,binding){element.value = binding.value},
//指令所在元素被插入页面时
inserted(element,binding){element.focus()},
//指令所在的模板被重新解析时
update(element,binding){element.value = binding.value}
})
//定义混入
Vue.mixin({
data() {return {x:100,y:200}},
})
//给Vue原型上添加一个方法（vm和vc就都能用了）
Vue.prototype.hello = ()=>{alert('你好啊')}
}
}
main.js
import Vue from 'vue'
import App from './App.vue'
import plugins from './plugins' // 引入插件
Vue.config.productionTip = false
Vue.use(plugins,1,2,3) // 应用（使用）插件
new Vue({
el:'#app',
render: h => h(App)
})
School.vue
<template>
<div>
<h2>学校名称：{{ name | mySlice }}</h2>
<h2>学校地址：{{ address }}</h2>
<button @click="test">点我测试一个hello方法</button>
</div>
</template>
<script>
export default {
name:'School',
data() {
return {
name:'尚硅谷atguigu',
address:'北京',
}
},
methods: {
test(){
this.hello()
}
},
}
</script>
Student.vue
<template>
<div>
<h2>学生姓名：{{ name }}</h2>
<h2>学生性别：{{ sex }}</h2>
<input type="text" v-fbind:value="name">
</div>
</template>
<script>
export default {
name:'Student',
data() {
return {
name:'张三',
sex:'男'
}
},
}
</script>
scoped
- 作用：让样式在局部生效，防止冲突
- 写法：<style scoped>
School.vue
<template>
<div class="demo">
<h2 class="title">学校名称：{{ name }}</h2>
<h2>学校地址：{{ address }}</h2>
</div>
</template>
<script>
export default {
name:'School',
data() {
return {
name:'尚硅谷atguigu',
address:'北京',
}
}
}
</script>
<style scoped>
.demo{
background-color: skyblue;
}
</style>
Student.vue
<template>
<div class="demo">
<h2 class="title">学生姓名：{{ name }}</h2>
<h2 class="atguigu">学生性别：{{ sex }}</h2>
</div>
</template>
<script>
export default {
name: 'Student',
data() {
return {
name: '张三',
sex: '男'
}
}
}
</script>
<style lang="less" scoped>
.demo {
background-color: pink;
.atguigu {
font-size: 40px;
}
}
</style>
App.vue
<template>
<div>
<h1 class="title">你好啊</h1>
<School/>
<Student/>
</div>
</template>
<script>
import Student from './components/Student'
import School from './components/School'
export default {
name: 'App',
components: { School, Student }
}
</script>
<style scoped>
.title {
color: red;
}
</style>
TodoList案例
App.vue
<template>
<div id="root">
<div class="todo-container">
<div class="todo-wrap">
<MyHeader :addTodo="addTodo" />
<MyList :todos="todos" :checkTodo="checkTodo" :deleteTodo="deleteTodo"/>
<MyFooter :todos="todos" :checkAllTodo="checkAllTodo" :clearAllTodo="clearAllTodo"/>
</div>
</div>
</div>
</template>
<script>
import MyHeader from "@/components/MyHeader.vue";
import MyFooter from "@/components/MyFooter.vue";
import MyList from "@/components/MyList.vue";
export default {
name: 'App',
components: {
MyHeader,
MyFooter,
MyList,
},
data(){
return {
todos: [
{id: '001', title: '抽烟', done: true},
{id: '002', title: '喝酒', done: true},
{id: '003', title: '烫头', done: true},
]
}
},
methods:{
// 添加todo
addTodo(todo){
this.todos.unshift(todo)
},
//勾选or取消勾选todo
checkTodo(id){
this.todos.forEach((todo)=>{
if (todo.id === id) todo.done = !todo.done
})
},
//删除todo
deleteTodo(id){
this.todos = this.todos.filter(todo => todo.id !== id)
},
// 全选or取消全选
checkAllTodo(done){
this.todos.forEach((todo)=>{
todo.done = done
})
},
//清除所有已经完成的todo
clearAllTodo(){
this.todos.filter((todo)=>{
return !todo.done
})
}
}
}
</script>
<style>
/*base*/
body {
background: #fff;
}
.btn {
display: inline-block;
padding: 4px 12px;
margin-bottom: 0;
font-size: 14px;
line-height: 20px;
text-align: center;
vertical-align: middle;
cursor: pointer;
box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2), 0 1px 2px rgba(0, 0, 0, 0.05);
border-radius: 4px;
}
.btn-danger {
color: #fff;
background-color: #da4f49;
border: 1px solid #bd362f;
}
.btn-danger:hover {
color: #fff;
background-color: #bd362f;
}
.btn:focus {
outline: none;
}
.todo-container {
width: 600px;
margin: 0 auto;
}
.todo-container .todo-wrap {
padding: 10px;
border: 1px solid #ddd;
border-radius: 5px;
}
</style>
MyHeader.vue
<template>
<div class="todo-header">
<input type="text" placeholder="请输入你的任务名称，按回车键确认"
v-model="title" @keyup.enter="add"/>
</div>
</template>
<script>
import {nanoid} from "nanoid";
export default {
name: 'MyHeader',
data() {
return {
title:'',
}
},
props:['addTodo'],
methods: {
add(){
// 校验数据
if(!this.title.trim()) return alert('输入不能为空')
// 将用户的输入包装成一个todo对象
const todoObj = { id:nanoid(), title:this.title, done:false }
// 通知App组件去添加一个todo对象
this.addTodo(todoObj)
// 清空输入
this.title = ''
},
},
}
</script>
<style scoped>
/*header*/
.todo-header input {
width: 560px;
height: 28px;
font-size: 14px;
border: 1px solid #ccc;
border-radius: 4px;
padding: 4px 7px;
}
.todo-header input:focus {
outline: none;
border-color: rgba(82, 168, 236, 0.8);
box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(82, 168, 236, 0.6);
}
</style>
MyList.vue
<template>
<ul class="todo-main">
<MyItem v-for="todo in todos" :key="todo.id" :todo="todo" :checkTodo="checkTodo" :deleteTodo="deleteTodo"/>
</ul>
</template>
<script>
import MyItem from "@/components/MyItem.vue";
export default {
name: 'MyList',
components: {
MyItem
},
props:['todos','checkTodo','deleteTodo'],
data() {
return {
}
},
methods: {},
}
</script>
<style scoped>
/*main*/
.todo-main {
margin-left: 0px;
border: 1px solid #ddd;
border-radius: 2px;
padding: 0px;
}
.todo-empty {
height: 40px;
line-height: 40px;
border: 1px solid #ddd;
border-radius: 2px;
padding-left: 5px;
margin-top: 10px;
}
</style>
MyItem.vue
<template>
<li>
<label>
<input type="checkbox" :checked="todo.done" @change="handleCheck(todo.id)"/>
<span>{{ todo.title }}</span>
</label>
<button class="btn btn-danger" @click="handleDelete(todo.id)">删除</button>
</li>
</template>
<script>
export default {
name: 'MyItem',
data() {
return {}
},
methods: {
// 勾选or取消勾选
handleCheck(id){
//通知app组件将对应的todo对象的done值取反
this.checkTodo(id)
},
// 删除
handleDelete(id){
if(confirm('确定删除吗？')){
this.deleteTodo(id)
}
}
},
props:['todo','checkTodo','deleteTodo'],
}
</script>
<style scoped>
/*item*/
li {
list-style: none;
height: 36px;
line-height: 36px;
padding: 0 5px;
border-bottom: 1px solid #ddd;
}
li label {
float: left;
cursor: pointer;
}
li label li input {
vertical-align: middle;
margin-right: 6px;
position: relative;
top: -1px;
}
li button {
float: right;
display: none;
margin-top: 3px;
}
li:before {
content: initial;
}
li:last-child {
border-bottom: none;
}
li:hover {
background-color: #ddd;
}
li:hover button {
display: block;
}
</style>
MyFooter.vue
<template>
<div class="todo-footer" v-show="total">
<label>
<!-- <input type="checkbox" :checked="isAll" @change="checkAll"/> -->
<input type="checkbox" v-model="isAll"/>
</label>
<span>
<span>已完成{{ doneTotal }}</span> / 全部{{ total }}
</span>
<button class="btn btn-danger" @click="clearAll">清除已完成任务</button>
</div>
</template>
<script>
export default {
name: 'MyFooter',
data() {
return {}
},
props:['todos','checkAllTodo','clearAllTodo'],
computed:{
total(){
return this.todos.length
},
doneTotal(){
return this.todos.reduce((pre,current)=> pre + (current.done ? 1 : 0),0)
},
isAll:{
get(){
return this.doneTotal === this.total && this.total > 0
},
set(value){
this.checkAllTodo(value)
}
},
},
methods: {
// checkAll(e){
// this.checkAllTodo(e.target.checked)
// },
clearAll(){
this.clearAllTodo()
}
},
}
</script>
<style scoped>
/*footer*/
.todo-footer {
height: 40px;
line-height: 40px;
padding-left: 6px;
margin-top: 5px;
}
.todo-footer label {
display: inline-block;
margin-right: 20px;
cursor: pointer;
}
.todo-footer label input {
position: relative;
top: -1px;
vertical-align: middle;
margin-right: 5px;
}
.todo-footer button {
float: right;
margin-top: 5px;
}
</style>
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