<template>
  <div id="app">
  <!--父组件-->
  <input v-model="msg">
  <button v-on:click="notify">广播事件</button>
  <!--子组件-->
  <popup ref="child" ></popup>
  </div>
 </template>
 <script>
  import popup from '@/components/popup'
  export default {
  name: 'app',
  data: function () {
   return {
   msg: ''
   }
  },
  components: {
   popup
  },
  methods: {
   notify: function () {
   if (this.msg.trim()) {
    this.$refs.child.parentMsg(this.msg)
   }
   }
  }
  }
 </script>
 <style>
  #app {
  font-family: 'Avenir', Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  margin-top: 60px;
  }
 </style>

<template>
   <div>
   <ul>
    <li v-for="item in messages">父组件输入了：{{item}}</li>
   </ul>
   </div>
  </template>
  <style>
   body {
    background-color: #ffffff;
   }
  </style>
  <script>
  export default{
   name: 'popup',
   data: function () {
   return {
    messages: []
   }
   },
   methods: {
   parentMsg: function (msg) {
    this.messages.push(msg)
   }
   }
  }
  </script>