Vue--- VueX组件间通信链接（共有方法放入了扩展目录store里面） 1.2

<script>
  import PubSub from ‘pubsub-js‘
  import TodoHeader from ‘./TodoHeader.vue‘
  import TodoList from ‘./TodoList.vue‘
  import TodoFooter from ‘./TodoFooter.vue‘
  // import storageUtils from ‘../utils/storageUtils‘
  import {mapActions} from ‘vuex‘
  export default {
    mounted(){
      // 异步获取 todos数据 
      this.$store.dispatch(‘reqTodos‘)
    },
    components: {
      TodoHeader,
      TodoList,
      TodoFooter
    }
  };
</script>

<template>
  <ul class="todo-main">
    <TodoItem v-for="(todo,index) in todos" :todo="todo" :key="index" :index="index"></TodoItem>
  </ul>
</template>

<script>
  import {mapState} from ‘vuex‘
  import TodoItem from ‘./TodoItem.vue‘
  import storageUtil from ‘../utils/storageUtils.js‘
  export default {
    // 声明接收标签属性
    // props: [‘todos‘], // 会成为当前组件对象的属性, 可以在模板中直接访问, 也可以通过this来访问
    components: {
      TodoItem
    },
    computed:{
        ...mapState([‘todos‘])
    },
   watch: {
      todos: {
        deep: true, // 深度监视
        handler: storageUtil.saveTodos
      }
    }
  };
</script>

<style>
  .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>

import {ADD_TODO, DELETE_TODO, SELECT_ALL_TODOS, CLEAR_ALL_COMPLETED,RECEIVE_TODOS} from ‘./mutation-types‘
import storageUtil from ‘../utils/storageUtils.js‘
export default {
  addTodo ({commit}, todo) {
    commit(ADD_TODO, {todo})
  },
  deleteTodo({commit},index){
      commit(DELETE_TODO,{index})
  },
  selectAllTodos ({commit}, check) {
    commit(SELECT_ALL_TODOS, {check})
  },
  clearALLCompleted({commit}){
      commit(CLEAR_ALL_COMPLETED)
  },
  reqTodos({commit},todos){
      setTimeout(()=>{
          // 读取数据
      const todos = storageUtil.readTodos()
          // 提交数据
        commit(RECEIVE_TODOS,todos)
      },1000)
  }
}

// 引入 常量types.js   拿出来的都是变量名都是 字符串 
import {ADD_TODO, DELETE_TODO, SELECT_ALL_TODOS, CLEAR_ALL_COMPLETED,RECEIVE_TODOS} from ‘./mutation-types‘
// 给名称加 []号就是成为变量的 
// 
export default {
  [ADD_TODO] (state, {todo}) {
    state.todos.unshift(todo)
  },
  [DELETE_TODO] (state, {index}) {
    state.todos.splice(index, 1)
  },
  [SELECT_ALL_TODOS] (state,{check}){
      state.todos.forEach(todo => (todo.complete = check))
  },
  [CLEAR_ALL_COMPLETED](state){
      state.todos = state.todos.filter(todo => (!todo.complete))
  },
  [RECEIVE_TODOS](state,todos){
      state.todos = todos
  }
}