Vue2 - 23-03-26

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Vue2 - 23-03-26

一个错误

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ERROR in ./src/components/MyList.vue?vue&type=script&lang=js& (./node_modules/babel-loader/lib/index.js??clonedRuleSet-40.use[0]!./node_modules/@vue/vue-loader-v15/lib/index.js??vue-loader-options!./src/components/MyList.vue?vue&type=script&lang=js&)
Module build failed (from ./node_modules/babel-loader/lib/index.js):
SyntaxError: D:\CODE_VsCode\VUE\vue_study\脚手架之后的内容\vue_test\src\components\MyList.vue: Legacy octal literals are not allowed in strict mode. (7:16)

   5 |         data(){
   6 |           todos[
>  7 |             {id:001, title:抽烟, done: true},
     |                 ^
   8 |             {id:002, title:喝酒, done: false},
   9 |             {id:003, title:开车, done: false}
  10 |           ]

记得serve之前保存文件！！！

另一个错误

卡在这里不动了。。。

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 npm run serve

> [email protected] serve
> vue-cli-service serve

 INFO  Starting development server...
[24%] building (12/33 modules)

检查template里面是不是有错误，编译失败

子组件向父组件传数据

实现方式：父组件先向子组件传函数，子组件在合适的时候将数据通过调用父组件的函数，将数据传给父组件

css中父元素被hover的时候触发子元素的属性

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li:hover button {
  display: block;
}

获取点击事件的元素

e.target.value/e.target.checked

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v-on:click(funName)
funName(e) {
    log(e.target.value)/log(e.target.checked)
}

自行练习了一遍

App.vue

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<template>
  <div class="todo-container">
    <div class="todo-wrap">
        <MyHeader
            :addTodo="addTodo"/>
        <MyList
            :todos="todoList"
            :changeDone="changeDone"
            :deleteTodo="deleteTodo"
        />
        <MyFooter
            :todos="todoList"
            :checkAll='checkAll'
            :clearDone="clearDone"
        />
    </div>
  </div>
</template>

<script>
    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 {
                todoList:[
                    {id:'001', title:'抽烟', done:false},
                    {id:'002', title:'喝酒', done:true},
                    {id:'003', title:'吃饭', done:false},
                ]
            }
        },
        methods:{
            addTodo(todo) {
                // console.log('收到了todo',todo);
                this.todoList.unshift(todo)
            },
            changeDone(id) {
                this.todoList.forEach(todo => {
                    if(todo.id === id) todo.done = !todo.done
                });
            },
            deleteTodo(id) {
                this.todoList = this.todoList.filter((todo)=>{
                    return todo.id!=id
                })
            },
            checkAll(value) {
                
                    this.todoList.forEach((todo)=>{
                    todo.done = value
                })
            },
            clearDone() {
                if(confirm("将要清除所有已完成项") ){
                    this.todoList=this.todoList.filter(todo=> !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>

Header.vue

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<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="addATodo"/>
    </div>
</template>

<script>
    import {nanoid} from 'nanoid'
    export default {
        name:'MyHeader',
        props:["addTodo"],
        methods:{
            addATodo(e){
                const todo = {id:nanoid(),title:e.target.value,done:false}
                this.addTodo(todo)
                e.target.value=''
            }
        }
    }
</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

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<template>
    <ul class="todo-main">
        <!-- 每一份都是独一无二的vc -->
        <MyItem 
        v-for="todo in todos" 
        :key="todo.id"
        :todoItem="todo"
        :changeDone='changeDone'
        :deleteTodo='deleteTodo'
        />
    </ul>
</template>

<script>
    import MyItem from './MyItem.vue'
    export default {
        name:'MyList',
        components:{MyItem},
        props:['todos','changeDone','deleteTodo']
    }
</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

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<template>
    <li>
        <label>
        <input type="checkbox" :checked="todoItem.done" @change="handleDone"/>
        <span>{{todoItem.title}}</span>
        </label>
        <button class="btn btn-danger" @click="handleDelete">删除</button>
    </li>
</template>

<script>
    export default {
        name:'MyItem',
        props:['todoItem','changeDone','deleteTodo'],
        methods:{
            handleDone(){
                // console.log('点了');
                this.changeDone(this.todoItem.id)
            },
            handleDelete(){
                if(confirm("确认要删除这一项吗？？")) this.deleteTodo(this.todoItem.id)
            }
        }
    }
</script>

<style scoped>
/*item*/
li {
  list-style: none;
  height: 36px;
  line-height: 36px;
  padding: 0 5px;
  border-bottom: 1px solid #ddd;
}

li:hover {
    background-color: #ebebeb;
}

li:hover button {
    display: block;
}

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;
}
</style>

MyFooter.vue

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<template>
<div class="todo-footer" v-show="todoTotal>0">
  <label>
    <input type="checkbox" v-model="isAll"/>
  </label>
  <span>
    <span>已完成{{todoDone}}</span> / 全部{{todoTotal}}
  </span>
  <button class="btn btn-danger" @click="clearDone">清除已完成任务</button>
</div>
</template>

<script>
    export default {
        name:'MyFooter',
        props:['todos','checkAll','clearDone'],
        computed:{
            todoTotal(){
                return this.todos.length;
            },
            todoDone(){
                return this.todos.reduce((pre,todo)=>{
                    return pre += todo.done? 1: 0
                },0)
            },
            isAll:{
                get(){
                    return this.todoDone === this.todoTotal
                },
                set(checked){
                    this.checkAll(checked)
                }
            }
        }
    }
</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>

WebStorage

增(window.)localStorage/sessionStorage . setItem([key],[value])
查(window.)localStorage/sessionStorage . getItem([key])
单删(window.)localStorage/sessionStorage . removeItem([key])
全删(window.)localStorage/sessionStorage . clear

转字符串JSON.stringify / 恢复对象JSON.parse

TodoList新增本地存储功能

防止初始的时候key不存在

todoList: JSON.parse(localStorage.getItem("todos")) || []

实现

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watch:{
  todoList:{
    deep:true,
    handler(value) {
      localStorage.setItem('todos',JSON.stringify(value))
    }
  }
}

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