vue--day54--todolist 中的MyItem 和App 消息发布实现通信

发布时间 2023-08-04 23:13:34作者: 雪落无痕1

1.App.vue

<template>
<div id="root">
<div class="todo-container">
<div class="todo-wrap">
<!-- @addTodo 事件名 addTodo 回调名-->
<MyHeader @addTodo="addTodo"/>
<!--父亲给儿子传数据 父亲通过数据绑定传数据 儿子通过 props:['todos'],//声明接收todo 对象 -->
<MyList :todos="todos" :checkTodo="checkTodo" :deleteTodo="deleteTodo"/>
<MyFooter :todos="todos" @checkAllTodo="checkAllTodo" @clearAllTodo="clearAllTodo"/>
</div>
</div>
</div>
 
 
</template>
 
<script>
//样式的引入和这里有关系
import pubsub from 'pubsub-js'
import MyHeader from './components/MyHeader.vue';
import MyList from './components/MyList.vue';
import MyFooter from './components/MyFooter.vue';
 
 
export default {
name: 'App',
components: {
MyHeader,
MyList,
MyFooter
},
data(){
return {
todos:JSON.parse(localStorage.getItem("todos"))||[]
}
 
},
 
methods:{
// 添加一个todo
addTodo(todoObj){
// console.log('我是app组件,我收到了数据x==',todoObj);
this.todos.unshift(todoObj)
 
},
//勾选or 取消勾选 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or全不选
checkAllTodo(done){
this.todos.forEach((todo)=>{
todo.done=done
})
},
 
clearAllTodo(){
this.todos=this.todos.filter((todo)=>{
return !todo.done
})
}
 
},
watch:{
// todos(value){
// localStorage.setItem("todos", JSON.stringify(value));
// }
todos:{
deep:true,
handler(value){
localStorage.setItem("todos", JSON.stringify(value));
}
}
 
},
mounted(){
this.$bus.$on('checkTodo',this.checkTodo)
//this.$bus.$on('deleteTodo',this.deleteTodo)
this.pubId=pubsub.subscribe('deleteTodo',this.deleteTodo)

},
beforeDestroy(){
this.$bus.$off('checkTodo')
//this.$bus.$off('deleteTodo')
pubsub.unsubscribe(this.pubId)
}
}
</script>
 
<style>
 
 
/* 整体样式 */
body {
background: rgba(230, 241, 245, 0.816);
}
 
.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>
2. MyItem.vue
<template>
<li>
<label>
<input type="checkbox" :checked="todo.done" @click="handlerCheck(todo.id)"/>

<!--

let a=1;
a=2;
改了
let obj={a:1,b:2}
obj.a=8; 代码层底改了 但是 obj 内存地址没有变化 vue 认为没有变化
如下代码也能实现功能 但是步太推荐 因为有点违反了原则 因为修改了 props 属性
-->
<!-- <input type="checkbox" v-model:="todo.done"/> -->

 
<span>{{todo.title}}</span>
</label>
<button class="btn btn-danger" @click="hadnlerDelete(todo.id)">删除</button>
</li>
</template>

<script>
import pubsub from 'pubsub-js'
export default {
name:"MyItem",
props:['todo'],//声明接收todo 对象
mounted(){
//console.log(this.todo);
},
methods:{
//勾选或者取消勾选
handlerCheck(id){
//通知app 组件 将对应的todo 对象的done 值取反
//console.log("id",id);
//this.checkTodo(id);

this.$bus.$emit('checkTodo',id)
},
//闪促
hadnlerDelete(id){
if(confirm('确定删除么')){
//console.log("id",id);

//通知app 删除一个对象
//this.deleteTodo(id);
// this.$bus.$emit('deleteTodo',id)

pubsub.publish('deleteTodo',id)

}
}
}
}
</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:hover {
background-color: grey;
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:hover button {
display: block;
}

li:before {
content: initial;
}

li:last-child {
border-bottom: none;
}

</style>