How to use the parent-child component in Vue to communicate with the todolist component-JS Tutorial-php.cn

How to use the parent-child component in Vue to communicate with the todolist component

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Release： 2018-05-28 14:48:51

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This time I will show you how to use the parent-child component in Vue to communicate with the todolist component. What are the precautions for using the parent-child component in Vue to communicate with the todolist component. The following is a practical case, let's take a look.

1. Todolist function development

<p id="root">
  <p>
   <input type="text" v-model="inputValue">
   <button @click="handleSubmit">提交</button>
  </p>
  <ul>
   <li v-for="(item, index ) of list" :key="index">{{item}} </li>
  </ul>
 </p>
 <script>
 new Vue({
  el:"#root",
  data:{
   inputValue:'',
   list:[]
  },
  methods:{
   handleSubmit:function(){
    this.list.push(this.inputValue);
    this.inputValue='';
   }
  }
 })
 </script>

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2. Todolist component split

Define components, communicate between components

1. Global components

 <p id="root">
  <p>
   <input type="text" v-model="inputValue">
   <button @click="handleSubmit">提交</button>
  </p>
  <ul>
   <todo-item></todo-item>
  </ul>
 </p>
 <script>
 Vue.component('todo-item',{
  template:'<li>item</li>'
 })
...

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2. Local components

need to be registered, otherwise an error will be reported:

vue.js:597 [Vue warn]: Unknown custom element: - did you register the component correctly? For recursive components, make sure to provide the "name" option.

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 <meta http-equiv="X-UA-Compatible" content="ie=edge">
 <title>Document</title>
 <script src="./vue.js"></script>
</head>
<body>
 <p id="root">
  <p>
   <input type="text" v-model="inputValue">
   <button @click="handleSubmit">提交</button>
  </p>
  <ul>
   <todo-item></todo-item>
  </ul>
 </p>
 <script>
 //全局组件
 // Vue.component('todo-item',{
 //  template:'<li>item</li>'
 // })
 var TodoItem={
  template:'<li>item</li>'
 }
 new Vue({
  el:"#root",
  components:{
   'todo-item':TodoItem
  },
  data:{
   inputValue:'',
   list:[]
  },
  methods:{
   handleSubmit:function(){
    this.list.push(this.inputValue);
    this.inputValue='';
   }
  }
 })
 </script>
</body>
</html>

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3、Component Passing values

The parent component passes values to the child components in the form of attributes.

<p id="root">
  <p>
   <input type="text" v-model="inputValue">
   <button @click="handleSubmit">提交</button>
  </p>
  <ul>
   <todo-item 
    v-for="(item ,index) of list"
    :key="index"
    :content="item"
   ></todo-item>
  </ul>
 </p>
 <script>
 Vue.component('todo-item',{
  props: ['content'], //接收从外部传递进来的content属性
  template:'<li>{{content}}</li>'
 })
 new Vue({
  el:"#root",
  data:{
   inputValue:'',
   list:[]
  },
  methods:{
   handleSubmit:function(){
    this.list.push(this.inputValue);
    this.inputValue='';
   }
  }
 })
 </script>

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3. The relationship between components and instances

new Vue() instance

Vue .component is a component

Each Vue component is an instance of Vue.

Any vue project is composed of thousands of vue instances.

Each vue instance is a component, and each component is also an instance of vue.

4. Implement the delete function of todolist

The child component notifies the parent component through the publish-subscribe mode.

<p id="root">
  <p>
   <input type="text" v-model="inputValue">
   <button @click="handleSubmit">提交</button>
  </p>
  <ul>
   <todo-item 
    v-for="(item ,index) of list"
    :key="index"
    :content="item"
    :index="index"
    @delete=&#39;handleDelete&#39;
   ></todo-item>
  </ul>
 </p>
 <script>
 Vue.component('todo-item',{
  props: ['content','index'], //接收从外部传递进来的content属性
  template:'<li @click="handleDeleteItem">{{content}}</li>',
  methods:{
   handleDeleteItem:function(){
    this.$emit('delete',this.index);
   }
  }
 })
 new Vue({
  el:"#root",
  data:{
   inputValue:'',
   list:[]
  },
  methods:{
   handleSubmit:function(){
    this.list.push(this.inputValue);
    this.inputValue='';
   },
   handleDelete:function(index){
    this.list.splice(index,1);

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I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!