总结ToDoList案例:
1.组件化编码流程:
(1).拆分静态组件:组件要按照功能点拆分,命名不要与html元素冲突.
(2).实现动态组件:考虑好数据的存放位置,数据是一个组件再用,还是一些组件在用.
a:一个组件在用,放在自身即可.
b:一些组件在用,放在他们共同的父组件上(状态提升).
(3).实现交互:从绑定事件开始.
2.props适用于:
(1).父组件 ===> 子组件 通信
(2).子组件 ===> 父组件 通信 (要求父组件先给子组件一个函数)
3.使用v-model时要注意:v-model绑定的值不能是props传过来的值,因为props是不可以修改的.
4.props传过来的若是对象类型的值,修改对象中的属性事,vue不会报错,但不推荐这样做.
我这些代码都是跟着老师敲的,其中已经运用到了组件自定义事件和全局事件总栈,有代码需要的小伙伴可以自行删除.
App.vue
//App.vue
<template>
<div id="root">
<div class="todo-container">
<div class="todo-wrap">
<MyHeader @addTodo="addTodo"></MyHeader>
<MyList :todos="todos"></MyList>
<MyFooter
:todos="todos"
@checkAllTodo="checkAllTodo"
@clearAllTodo="clearAllTodo"
>
</MyFooter>
</div>
</div>
</div>
</template>
<script>
import MyHeader from "../src/components/MyHeader";
import MyList from "../src/components/MyList";
import MyFooter from "../src/components/MyFooter";
export default {
name: "App",
components: {
MyHeader,
MyList,
MyFooter,
},
data() {
return {
todos: JSON.parse(localStorage.getItem("todos")) || [],
};
},
methods: {
// 添加一个todo
addTodo(todoObj) {
this.todos.unshift(todoObj);
},
// 勾选或取消勾选一个todo
checkTodo(id) {
this.todos.forEach((todo) => {
if (todo.id === id) todo.done = !todo.done;
});
},
// 删除一个todo
deleteTodo(id) {
this.todos = this.todos.filter((todo) => {
return todo.id !== id;
});
},
// 全选或取消全选
checkAllTodo(done) {
this.todos.forEach((todo) => {
todo.done = done;
});
},
// 清除所有已经完成的todo
clearAllTodo() {
this.todos = this.todos.filter((todo) => {
return !todo.done;
});
},
},
watch: {
todos: {
deep: true,
handler(value) {
localStorage.setItem("todos", JSON.stringify(value));
},
},
},
mounted(){
this.$bus.$on('checkTodo',this.checkTodo)
this.$bus.$on('deleteTodo',this.deleteTodo)
},
beforeDestroy(){
this.$bus.$off('checkTodo')
this.$bus.$off('deleteTodo')
}
};
</script>
<style>
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
//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"
@keyup.enter="add"
v-model="title"
/>
</div>
</template>
<script>
import { nanoid } from 'nanoid'
export default {
name: "MyHeader",
data() {
return {
title:''
};
},
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对象
const todoObj = { id: nanoid(), title: this.title, done: false };
// 通知App组件去添加一个对象
this.$emit('addTodo',todoObj);
//清空输入
this.title = '';
},
},
};
</script>
<style scoped>
.todo-header input {
width: 560px;
height: 28px;
font-size: 14px;
border: 1px solid #ccc;
border-radius: 4px;
padding: 4px 7px;
}
.todo-header input:focus {
outline: none;
border-color: rgba(82, 168, 236, 0.8);
box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075),
0 0 8px rgba(82, 168, 236, 0.6);
}
</style>MyList.vue
//MyList.vue
<template>
<ul class="todo-main">
<MyItem
v-for="todoObj in todos"
:key="todoObj.id"
:todo="todoObj"
/>
</ul>
</template>
<script>
import MyItem from "./MyItem.vue";
export default {
name: "MyList",
components: { MyItem },
// 声明接收App传过来的数据
props:['todos']
};
</script>
<style scoped>
.todo-main {
margin-left: 0px;
border: 1px solid #ddd;
border-radius: 2px;
padding: 0px;
}
.todo-empty {
height: 40px;
line-height: 40px;
border: 1px solid #ddd;
border-radius: 2px;
padding-left: 5px;
margin-top: 10px;
}
</style>MyItem.vue
//MyItem.vue
<template>
<li>
<label>
<input
type="checkbox"
:checked="todo.done"
@change="handleCheck(todo.id)"
/>
<!-- 如下代码也能实现功能,但是不太推荐,因为有点违反原则,因为修改了props -->
<!-- <input type="checkbox" v-model="todo.done"/> -->
<span>{{ todo.title }}</span>
</label>
<button class="btn btn-danger" @click="handleDelete(todo.id)">删除</button>
</li>
</template>
<script>
export default {
name: "MyItem",
//声明接收todo对象
props: ["todo"],
methods: {
//勾选or取消勾选
handleCheck(id) {
// 通知App将对应的todo的done值取反
// this.checkTodo(id);
this.$bus.$emit('checkTodo', id);
},
// 删除
handleDelete(id) {
if (confirm("确定删除吗?")) {
// this.deleteTodo(id);
this.$bus.$emit('deleteTodo', id);
}
},
},
};
</script>
<style scoped>
li {
list-style: none;
height: 36px;
line-height: 36px;
padding: 0 5px;
border-bottom: 1px solid #ddd;
}
li label {
float: left;
cursor: pointer;
}
li label li input {
vertical-align: middle;
margin-right: 6px;
position: relative;
top: -1px;
}
li button {
float: right;
display: none;
margin-top: 3px;
}
li:before {
content: initial;
}
li:last-child {
border-bottom: none;
}
li:hover {
background-color: #ccc;
}
li:hover button {
display: block;
}
</style>MyFooter.vue
MyFooter.vue
<template>
<div class="todo-footer" v-if="total">
<label>
<!-- <input type="checkbox" :checked="isAll" @change="checkAll"/> -->
<input type="checkbox" v-model="isAll"/>
</label>
<span>
<span>已完成{{ doneTotal }} </span> / 全部{{ total }}
</span>
<button class="btn btn-danger" @click="clearAll">清除已完成任务</button>
</div>
</template>
<script>
export default {
name: "MyFooter",
props:['todos'],
computed:{
total(){
return this.todos.length
},
// 第一种方法
// doneTotal(){
// let i = 0
// this.todos.forEach((todo) => {
// if(todo.done) i++
// })
// return i
// }
// 第二种方法
doneTotal(){
// const x = this.todos.reduce((pre,current)=>{
// console.log('@',pre,current)
// return pre + (current.done ? 1 : 0)
// },0)
// 简写
return this.todos.reduce((pre,current)=> pre + (current.done ? 1 : 0),0)
},
isAll:{
get(){
return this.doneTotal === this.total && this.total > 0
},
set(value){
this.$emit('checkAllTodo',value)
}
}
},
methods:{
checkAll(e){
this.checkAllTodo(e.target.checked)
},
clearAll(){
this.$emit('clearAllTodo')
}
}
};
</script>
<style scoped>
.todo-footer {
height: 40px;
line-height: 40px;
padding-left: 6px;
margin-top: 5px;
}
.todo-footer label {
display: inline-block;
margin-right: 20px;
cursor: pointer;
}
.todo-footer label input {
position: relative;
top: -1px;
vertical-align: middle;
margin-right: 5px;
}
.todo-footer button {
float: right;
margin-top: 5px;
}
</style>main.js
//main.js
//引入vue
import Vue from 'vue'
//引入App
import App from './App.vue'
//关闭Vue的生产提示
Vue.config.productionTip = false
new Vue({
// 这里的"#app"的a为小写
el:"#app",
render: h => h(App),
//安装全局事件总线
beforeCreate(){
Vue.prototype.$bus = this
},
})
已经完成啦!可以实现增加,删除及统计功能.
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