Todo-List案例版本五

安装库npm i pubsub-js

消息的订阅与发布

src/App.vue

<template>
    <div class="app">
        <h1>{{ msg }}</h1>
        <School/>
        <Student/>
    </div>
</template>

<script>
import Student from './components/Student'
import School from './components/School'

export default {
    name: 'App',
    data() {
        return {
            msg: '你好啊！'
        }
    },
    components: { Student, School }
}
</script>

<style scoped>
.app {
    background-color: gray;
    padding: 5px;
}
</style>

src/components/School.vue

<template>
    <div class="school">
        <h2>学校名称：{{ name}}</h2>
        <h2>学校地址：{{ address }}</h2>
    </div>
</template>

<script>
import pubsub from 'pubsub-js'
export default {
    name: 'School',
    data() {
        return {
            name:'黑马',
            address:'广州'
        }
    },
    methods:{
        demo(msgName,data){
            console.log('有人发布了hello消息，hello消息的回调执行了',msgName,data);
            console.log(this);// VueComponent
        }
    },
    mounted(){
        /* this.$bus.$on('hello',(data)=>{
            console.log('我是School组件，收到了数据',data);
        }) */

        /* this.pubId=pubsub.subscribe('hello',function(msgName,data){
            console.log('有人发布了hello消息，hello消息的回调执行了',msgName,data);
            console.log(this);// undefined
        }) */

        this.pubId=pubsub.subscribe('hello',this.demo)
    },
    beforeDestroy(){
        // this.$bus.$off('hello')
        pubsub.unsubscribe(pubId);
    }
}
</script>

<style scoped>
    .school{
        background-color: skyblue;
        padding: 5px;
    }
</style>

src/components/Student.vue

<template>
    <div class="student">
        <h2>学生姓名：{{ name }}</h2>
        <h2>学生性别：{{ sex }}</h2>
        <button @click="sendStudentName">发送学生名字到学校</button>
    </div>
</template>

<script>
import pubsub from 'pubsub-js'
export default {
    name: 'Student',
    data() {
        return {
            name:'张三',
            sex:'男'
        }
    },
    methods:{
        sendStudentName(){
            // this.$bus.$emit('hello',this.name)
            pubsub.publish('hello',666)
        }
    }
}
</script>

<style lang="less">
    .student{
        background-color: pink;
        padding: 5px;
        margin-top: 30px;
    }
</style>

src/main.js

import Vue from 'vue'
import App from './App.vue'

Vue.config.productionTip = false

// Vue.prototype.x={a:1,b:2}

//创建vm
new Vue({
    el: '#app',
    render: h => h(App)
})

$nextTick(回调函数)

Todo-List最终完成版

hasOwnProperty和$set()和函数(参数,$event)使用

(161条消息) Todo-List案例版本四_bubbleJessica的博客-CSDN博客

src/components/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(){
            if(!this.title.trim()) return alert('输入不能为空！')
            // 给用户输入的内容包装成一个todoObj对象
            const todoObj={id:nanoid(),title:this.title,done:false};
            // this.addToDo(todoObj);
            this.$emit('addToDo',todoObj)
            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>

src/components/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',
    props:['todos'],
    components: { MyItem }
}
</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>

src/components/MyItem.vue

<template>
    <li>
        <label>
            <input type="checkbox" :checked="todo.done" @change="handleCheck(todo.id)" />
            <!-- 以下代码也能实现功能，但是不太推荐，因为有点违反规则，因为修改了props，只不过vue没有监测到（vue监测到的情况是对象全部被变化 -->
            <!-- <input type="checkbox" v-model="todo.done"/> -->
            <span v-show="!todo.isEdit">{{ todo.title }}</span>
            <input 
                v-show="todo.isEdit"
                type="text" 
                :value="todo.title"
                @blur="handleBlur(todo,$event)"
                ref="inputTitle"
            >
        </label>
        <button class="btn btn-danger" @click="handleDelete(todo.id)">删除</button>
        <button v-show="!todo.isEdit" class="btn btn-edit" @click="handleEdit(todo)">编辑</button>
    </li>
</template>

<script>
import pubsub from 'pubsub-js'
export default {
    name: 'MyItem',
    //声明接收todo对象
    props: ['todo'],
    methods: {
        // 勾选或者取消勾选
        handleCheck(id) {
            // 通知App组件将对应的todo对象的done值取反
            // console.log(id);
            // this.checkTodo(id)
            this.$bus.$emit('checkTodo',id)
        },
        // 删除
        handleDelete(id){
            if(confirm('确定删除吗？')){
                // this.deleteTodo(id)  //事件名 自定义事件
                // this.$bus.$emit('deleteTodo',id) //事件名 全局事件总线

                pubsub.publish('deleteTodo',id) //消息名                
            }     
        },
        // 编辑
        handleEdit(todo){
            if(todo.hasOwnProperty('isEdit')){
                todo.isEdit=true
            }else{
                this.$set(todo,'isEdit',true)
            }
            // console.log(todo);
            // 作用：等上面所有逻辑执行完模板渲染完成之后，再执行下面的函数
            this.$nextTick(function(){
                this.$refs.inputTitle.focus()
            })
        },
        // 失去焦点回调，（真正执行修改逻辑）
        handleBlur(todo,e){
            todo.isEdit=false
            if(!e.target.value.trim()) return alert('输入不能为空！')
            // console.log('updateTodo',todo.id,e.target.value);
            this.$bus.$emit('updateTodo',todo.id,e.target.value)
        }
    }
}
</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>

src/components/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',
    // props: ['todos','checkAllTodo','clearAllTodo'],
    props: ['todos'],
    computed: {
        total() {
            return this.todos.length
        },
        doneTotal() {
            // 数组.reduce()方法
            // const x = this.todos.reduce((pre, cur) => {
            //     return pre + (cur.done ? 1 : 0)
            // }, 0)
            // return x
            return this.todos.reduce((pre, todo) => pre + (todo.done ? 1 : 0), 0)
        },
        // 计算属性简写版
        // isAll() {
        //     return this.doneTotal === this.total && this.total > 0
        // }

        // 计算属性完整版
        isAll:{
            get(){
                return this.doneTotal === this.total && this.total > 0
            },
            set(value){
                // this.checkAllTodo(value);
                this.$emit('checkAllTodo',value)
            }
        }
    },
    // methods:{
    //     checkAll(e){
    //         // console.log(e.target.checked);
    //         this.checkAllTodo(e.target.checked);
    //     }
    // }
    methods:{
        clearAll(){
            // this.clearAllTodo()
            this.$emit('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>

src/App.vue

<template>
    <div id="root">
        <div class="todo-container">
            <div class="todo-wrap">
                <MyHeader @addToDo="addToDo" />
                <MyList :todos="todos" />
                <MyFooter :todos="todos" @checkAllTodo="checkAllTodo" @clearAllTodo="clearAllTodo" />
            </div>
        </div>
    </div>
</template>

<script>
import pubsub from 'pubsub-js'
import MyHeader from './components/MyHeader'
import MyList from './components/MyList'
import MyFooter from './components/MyFooter'

export default {
    name: 'App',
    data() {
        return {
            // 由于todos是MyHeader组件和MyFooter组件都在使用，所以放在App中（状态提升）
            todos: JSON.parse(localStorage.getItem('todos')) || []
        }
    },
    components: { MyHeader, MyList, MyFooter },
    methods: {
        // 添加一个todo
        addToDo(todoObj) {
            this.todos.unshift(todoObj)
        },
        // 勾选or取消勾选一个todo
        checkTodo(id) {
            this.todos.forEach((todo) => {
                if (todo.id === id) todo.done = !todo.done
            })
        },
        // 更新一个todo
        updateTodo(id,title) {
            this.todos.forEach((todo) => {
                if (todo.id === id) todo.title = title
            })
        },
        // 删除一个todo
        deleteTodo(_,id) {
            // 注意:filter不改变原数组，只是新建一个数组
            this.todos = this.todos.filter((todo) => {
                return todo.id !== id
            })
        },
        // 全选or取消全选
        checkAllTodo(done) {
            this.todos.forEach((todo) => {
                todo.done = done
            })
        },
        // 清除所有已完成的todo
        clearAllTodo() {
            this.todos = this.todos.filter((todo) => {
                return !todo.done
            })
        }
    },
    watch: {
        // todos简写不包含深度监视
        // todos(value) {
        //     localStorage.setItem('todos', JSON.stringify(value))
        // }

        // todos完整版深度监视
        todos:{
            deep:true,
            handler(value){
                localStorage.setItem('todos', JSON.stringify(value))
            }
        }
    },
    mounted(){
        this.$bus.$on('checkTodo',this.checkTodo)
        this.$bus.$on('updateTodo',this.updateTodo)
        // this.$bus.$on('deleteTodo',this.deleteTodo)
        this.pubId=pubsub.subscribe('deleteTodo',this.deleteTodo)
    },
    beforeDestroy() {
        this.$bus.$off('checkTodo')
        this.$bus.$off('updateTodo')
        // this.$bus.$off('deleteTodo')
        pubsub.unsubscribe(this.pubId)
    },
}
</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-edit {
    color: #fff;
    background-color: skyblue;
    border: 1px solid rgb(182, 223, 240);
    margin-right: 5px;
}

.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>

src/main.js

import Vue from 'vue'
import App from './App.vue'

Vue.config.productionTip = false

//创建vm
new Vue({
    el: '#app',
    render: h => h(App),
    beforeCreate(){
        Vue.prototype.$bus=this //安装全局事件总线
    }
})