vuex日志插件（createLogger）

store/index.js：

import Vue from 'vue'
import Vuex from 'vuex'
import school from './school'
import { createLogger } from 'vuex'
import logger from 'vuex/dist/logger'

Vue.use(Vuex)

const store = new Vuex.Store({
  state: { number: 100, name: '小明' },
  mutations: {
    setNumber(state, val) {
      state.number++
      console.log(val)
    },
    changeName(state, val) {
      state.name = val
    }
  },
  actions: {
    setNumberAction({ commit, state }, val) {
      // commit('setNumber', val)
      state.number++ // strict: true 时，必须通过commit触发mutations中的方法，否则报错
    }
  },
  modules: { school },
  plugins: process.env.NODE_ENV !== 'production' ? [logger()] : [], // 或者写 [createLogger()]
  strict: true // 严格模式，禁止在actions中修改state中的数据
})

export default store

store/school/index.js：

export default {
  namespaced: true,
  state: {
    name: '杭州市第一中学'
  },
  mutations: {
    changeName(state, val) {
      state.name = val
    }
  }
}

App.vue：

<template>
  <div id="app">
    <p>{{$store.state.number}}</p>
    <p>{{number}}</p>
    <el-button @click="handleAdd">+</el-button>
    <p>{{name}}</p>
    <hr>
    <p>{{$store.state.school.name}}</p>
    <el-button @click="handleChangeName">改变名字</el-button>
  </div>
</template>
<script>
import { mapState, mapMutations, mapActions } from 'vuex'
export default {
  computed: {
    ...mapState({
      number: (state) => state.number,
      name: (state) => state.name
    })
  },
  methods: {
    handleAdd() {
      // this.$store.commit('setNumber')
      // this.setNumber(123)
      // this.$store.dispatch('setNumberAction', 123)
      this.setNumberAction(123)
    },
    ...mapMutations({ setNumber: 'setNumber' }),
    ...mapActions({ setNumberAction: 'setNumberAction' }),
    handleChangeName() {
      this.$store.commit('school/changeName', '浙江省第一小学')
    }
  }
}
</script>

总结：

　　1、引入日志插件后，每次操作state中的值，都会打印数据状态，并且会区别是actions还是mutations。如果是子模块会在方法名前加上子模块名。

　　

　　2、strict: true 设置严格模式后，actions中不能直接通过 state.name = val 去修改state中的值，而要通过commit去触发mutations中的方法修改state，否则报错

　　3、子模块中一般会设置 namespaced: true 在使用school中的属性和方法时，要在属性和方法前加上子模块名school

...mapState({ schoolName: (state) => state.school.name })

...mapMutations({ changeSchoolName: 'school/changeName' })