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

php中世界最好的语言Original: 2018-05-28 14:48:512116browse

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>

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>'
 })
...

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>

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>

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);

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!

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

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