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weex里Vuex state使用storage持久化详解

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const storage = weex.requireModule('storage')

定义state

var state = {

  banner:[],

  activeTabIndex:0,

  lists: {

    searchList:[],

    tabColumns: {

      new:[],

      hot:[],

      select:[]

    },

    items:[]

  }

} 

初始化时,从storage加载state数据 

// 从storage里加载数据

storage.getItem(STORAGE_KEY, event => {

 if (event.result == "success" && event.data){

   // 这里可以使用extend等方法,这里仅举例说明

   var data = JSON.parse(event.data);

   state.banner = data.banner;

   state.activeTabIndex = data.activeTabIndex;

 }

}) 

关键来了,如何存储?Vuex提供了插件机制,我们可以通过插件订阅state的每一次更改,在更改的时候保存我们感兴趣的就OK了

// 存储plugin,存储感兴趣的数据,store里数据太多,没必要全持久化

const storagePlugin = store => {

 store.subscribe((mutation, {activeTabIndex,banner}) => {

  storage.setItem(STORAGE_KEY, JSON.stringify({activeTabIndex,banner}),event => {

   console.log('cache success');

  })

 })

} 

最后,创建Vuex,大功告成 

const store = new Vuex.Store({

 actions,

 mutations,

 plugins:[storagePlugin],

 

 state: state,

 

 getters: {

  // ids of the items that should be currently displayed based on

  // current list type and current pagination

  activeIds (state) {

   const { activeType, lists, counts } = state

   return activeType ? lists[activeType].slice(0, counts[activeType]) : []

  },

 

  // items that should be currently displayed.

  // this Array may not be fully fetched.

  activeItems (state, getters) {

   return getters.activeIds.map(id => state.items[id]).filter(_ => _)

  }

 }

}) 

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。