vuex modules模块

1. modules中的state

export default () => {
  return new Vuex.Store({
    modules: {
      a: {
        state: {
          text: 1
        }
      },
      b: {
        state: {
          text: 2
        }
      }
    }
  })
}

computed: {
    textA () {
      return this.$store.state.a.text // 1
    }
  }

或者

...mapState({
  textA: (state) => state.a.text
})

2.modules中的mutation

直接可以在mapMutations中使用modules中的mutation

modules: {
  a: {
    state: {
      text: 1
    },
    mutations: {
      updateText (state, text) {
        console.log('a.state', state)
        state.text = text
      }
    }
  }
}

mounted () {
  this.updateText('123')
},
methods: {
  ...mapMutations(['updateText'])
}

3. 为modules中的mutation加上命名空间

modules: {
  a: {
    namespaced: true,
    state: {
      text: 1
    },
    mutations: {
      updateText (state, text) {
        console.log('a.state', state)
        state.text = text
      }
    }
  }
}

有命名空间时的调用方式

mounted () {
  this['a/updateText']('123')
},
methods: {
  ...mapMutations(['a/updateText'])
}

4. modules中的getter

modules: {
  a: {
    namespaced: true,
    state: {
      text: 1
    },
    getters: {
      textPlus (state) {
        return state.text + 1
      }
    }
  }
}

computed: {
  ...mapGetters({
    textPlus: 'a/textPlus'
  })
}

5. 为modules中的getter调用全局的state

getters: {
  textPlus (state, getters, rootState) {
    return state.text + rootState.count
  }
}

getter调用另一个module的state

getters: {
  textPlus (state, getters, rootState) {
    return state.text + rootState.b.text
  }
}

6. modules中的action 修改全局的mutation

actions: {
  add ({state, commit, rootState}) {
    commit('updateCount', rootState.count)
  }
}

此时，控制台会报错[vuex] unknown local mutation type: updateCount, global type: a/updateCount
需要允许module调用全局的mutation

 add ({state, commit, rootState}) {
    commit('updateCount', {num: 999}, {root: true})
  }

7. modules b 的action调用modules a 的mutation

modules: {
  a: {
    namespaced: true,
    state: {
      text: 1
    },
    mutations: {
      updateText (state, text) {
        console.log('a.state', state)
        state.text = text
      }
    }
  },
  b: {
    actions: {
      testAction ({commit}) {
        commit('a/updateText', 'test text')
      }
    }
  }
}

mounted () {
  this.testAction()
},
methods: {
  ...mapActions(['testAction'])
}

给modules b 加上命名空间

b: {
  namespaced: true,
  state: {
    text: 2
  },
  actions: {
    testAction ({commit}) {
      commit('a/updateText', 'test text', {root: true})
    }
  }
}

此时调用也需要加上命名空间

mounted () {
  this['b/testAction']()
},
methods: {
  ...mapActions(['b/testAction'])
}

module中也可嵌套模块

动态加载module

// main.js
store.registerModule('c', {
  state: {
    text: 3
  }
})

为vuex添加热更新的功能

export default () => {
  const store = new Vuex.Store({
    strict: isDev,
    state: defaultState,
    mutations,
    getters,
    actions
  })
  if (module.hot) {
    module.hot.accept([
      './state/state',
      './mutations/mutations',
      './getters/getters',
      './action/action'
    ], () => {
      const newState = require('./state/state').default
      const newMutations = require('./mutations/mutations').default
      const newGetters = require('./getters/getters').default
      const newActions = require('./action/action').default

      store.hotUpdate({
        state: newState,
        mutations: newMutations,
        getters: newGetters,
        actions: newActions
      })
    })
  }
  return store
}