vue发布订阅

1、安装 npm i --save pubsub-js

2、引入 import PubSub from ‘pubsub-js‘

 1 <template>
 2     <li
 3       @mouseenter="dealShow(true)"
 4       @mouseleave="dealShow(false)"
 5       :style="{backgroundColor: bgColor}"
 6     >
 7         <label>
 8             <input type="checkbox" v-model="todo.finished"/>
 9             <span>{{todo.title}}</span>
10         </label>
11         <button v-show="isShowDelButton"  class="btn btn-warning" @click="delItem">删除</button>
12     </li>
13 </template>
14 
15 <script>
16     import PubSub from ‘pubsub-js‘
17     export default {
18         name: "Item",
19         props: {
20             todo: Object,
21             index: Number, // 当前任务在总任务数组中的下标位置
22             delTodo: Function
23         },
24         data(){
25           return{
26               isShowDelButton: false,  // false 隐藏 true 显示
27               bgColor: ‘#fff‘
28           }
29         },
30         methods: {
31             dealShow(isShow){
32                 // 控制按钮的显示和隐藏
33                 this.isShowDelButton =  isShow;
34                 // 控制背景颜色
35                 this.bgColor = isShow ? ‘#ddd‘ : ‘#fff‘;
36             },
37 
38             delItem(){
39                 if(window.confirm(`您确定删除 ${this.todo.title} 吗?`)){
40                      // this.delTodo(this.index);
41                      // 发布消息
42                     PubSub.publish(‘delTodo‘, this.index)
43                 }
44             }
45         }
46     }
47 </script>
48 
49 <style scoped>
50     li {
51         list-style: none;
52         height: 36px;
53         line-height: 36px;
54         padding: 0 5px;
55         border-bottom: 1px solid #ddd;
56     }
57 
58     li label {
59         float: left;
60         cursor: pointer;
61     }
62 
63     li label li input {
64         vertical-align: middle;
65         margin-right: 6px;
66         position: relative;
67         top: -1px;
68     }
69 
70     li button {
71         padding: 4px 10px;
72         float: right;
73         margin-top: 3px;
74     }
75 
76     li:before {
77         content: initial;
78     }
79 
80     li:last-child {
81         border-bottom: none;
82     }
83 </style>

  1 <template>
  2     <div class="todo-container">
  3         <div class="todo-wrap">
  4             <Header ref="header"/>
  5             <List :todos="todos" :delTodo="delTodo"/>
  6             <Footer>
  7                 <input slot="isCheck" type="checkbox" v-model="isCheck"/>
  8                 <span slot="finish">已完成{{finishedCount}}件 / 总计{{todos.length}}件</span>
  9                 <button  slot="delete" class="btn btn-warning" @click="delFinishedTodos">清除已完成任务</button>
 10             </Footer>
 11         </div>
 12     </div>
 13 </template>
 14 
 15 <script>
 16     // 引入组件
 17     import Header from ‘./components/Header‘
 18     import List from ‘./components/List‘
 19     import Footer from ‘./components/Footer‘
 20 
 21     // 引入工具类
 22     import localStorageUtil from ‘./utils/localStorageUtil‘
 23     import PubSub from ‘pubsub-js‘
 24 
 25     export default {
 26         name: ‘app‘,
 27         data() {
 28             return {
 29                todos: localStorageUtil.readTodos()
 30             }
 31         },
 32         computed: {
 33             finishedCount() {
 34                 return this.todos.reduce((total, todo) => total + (todo.finished ? 1 : 0), 0);
 35             },
 36             isCheck: {
 37                 get() {
 38                     return this.finishedCount === this.todos.length && this.todos.length > 0
 39                 },
 40                 set(value) {
 41                     this.selectedAllTodo(value);
 42                 }
 43             }
 44         },
 45         components: {
 46             Header,
 47             List,
 48             Footer
 49         },
 50         mounted(){
 51            // 绑定自定义事件（addTodo）监听
 52            this.$refs.header.$on(‘addTodo‘, this.addTodo);
 53            // 订阅消息（delTodo）
 54            PubSub.subscribe(‘delTodo‘, (msg, token)=>{
 55                // console.log(msg, token);  msg=delTodo   token 参数
 56                this.delTodo(token);
 57            });
 58         },
 59         methods:{
 60             // 插入一条数据
 61             addTodo(todo){
 62                  this.todos.unshift(todo);
 63             },
 64             // 根据索引删除一条记录
 65             delTodo(index){
 66                 this.todos.splice(index, 1);
 67             },
 68             // 是否选中所有的任务
 69             selectedAllTodo(isCheck){
 70                this.todos.forEach(todo => {
 71                    todo.finished = isCheck
 72                })
 73             },
 74             delFinishedTodos(){
 75                 this.todos = this.todos.filter(todo=> !todo.finished)
 76             }
 77         },
 78         watch: {
 79             // 深度监视
 80             todos: {
 81                 handler: localStorageUtil.saveTodos,
 82                 deep: true, // 深度监视
 83                 // immediate: true
 84             }
 85         }
 86     }
 87 </script>
 88 
 89 <style>
 90     .todo-container {
 91         width: 600px;
 92         margin: 0 auto;
 93     }
 94 
 95     .todo-container .todo-wrap {
 96         padding: 10px;
 97         border: 1px solid #ddd;
 98         border-radius: 5px;
 99     }
100 </style>

子组件向父组件传值 props:向父组件的函数传递参数；自定义事件；发布订阅