Vuex的各个模块封装

一、各个模块的作用：

• state 用来数据共享数据存储
• mutation 用来注册改变数据状态（同步）
• getters 用来对共享数据进行过滤并计数操作
• action 解决异步改变共享数据（异步）

二、 创建文件：

actions.js

getters.js

index.js

mutations.js

mutation-types.js

state.js

三、编辑文件

这里只是拿出自己的项目来做一个例子，只是介绍封装的方法。

index.js

import Vue from 'vue'
import Vuex from 'vuex'
import * as actions from './actions'
import * as getters from './getters'
import state from './state'
import mutations from './mutations'
import createLogger from 'vuex/dist/logger' // vuex调试工具

Vue.use(Vuex)

const debug = process.env.NODE_ENV !== 'prodycution' // 开发环境下开启严格模式

export default new Vuex.Store({
	actions,
	getters,
	state,
	mutations,
	strict: debug,
	plugins: debug ? [createLogger()] : [] 
})

state.js

import {playMode} from 'common/js/config'
import {loadSearch} from 'common/js/cache'

const state = {
	singer: {},
	playing: false,
	fullScreen: false,
	playlist: [],
	sequenceList: [],
	mode: playMode.sequence,
	currentIndex: -1,
	disc: {},
	topList: {},
	searchHistory: loadSearch()
}

export default state

mutations.js

import * as types from './mutation-types'

const mutations = {
	[types.SET_SINGER](state, singer) {
		state.singer = singer
	},
	[types.SET_PLAYING_STATE](state, flag) {
		state.playing = flag
	},
	[types.SET_FULL_SCREEN](state, flag) {
		state.fullScreen = flag
	},
	[types.SET_PLAYLIST](state, list) {
		state.playlist = list
	},
	[types.SET_SEQUENCE_LIST](state, list) {
		state.sequenceList = list
	},
	[types.SET_PLAY_MODE](state, mode) {
		state.mode = mode
	},
	[types.SET_CURRENT_INDEX](state, index) {
		state.currentIndex = index
	},
	[types.SET_DISC](state, disc) {
		state.disc = disc
	},
	[types.SET_TOP_LIST](state, topList) {
		state.topList = topList
	},
	[types.SET_SEARCH_HISTORY](state, history) {
		state.searchHistory = history
	}
}

export default mutations

mutation-types.js

export const SET_SINGER = 'SET_SINGER'

export const SET_PLAYING_STATE = 'SET_PLAYING_STATE'

export const SET_FULL_SCREEN = 'SET_FULL_SCREEN'

export const SET_PLAYLIST = 'SET_PLAYLIST'

export const SET_SEQUENCE_LIST = 'SET_SEQUENCE_LIST'

export const SET_PLAY_MODE = 'SET_PLAY_MODE'

export const SET_CURRENT_INDEX = 'SET_CURRENT_INDEX'

export const SET_DISC = 'SET_DISC'

export const SET_TOP_LIST = 'SET_TOP_LIST'

export const SET_SEARCH_HISTORY = 'SET_SEARCH_HISTORY'

getters.js

export const singer = state => state.singer

export const playing = state => state.playing

export const fullScreen = state => state.fullScreen

export const playlist = state => state.playlist

export const sequenceList = state => state.sequenceList

export const mode = state => state.mode

export const currentIndex = state => state.currentIndex

export const currentSong = (state) => {
	return state.playlist[state.currentIndex] || {}
}

export const disc = state => state.disc

export const topList = state => state.topList

export const searchHistory = state => state.searchHistory

actions.js

import * as types from './mutation-types'
import {playMode} from 'common/js/config'
import {shuffle} from 'common/js/util'
import {saveSearch, deleteSearch, clearSearch} from 'common/js/cache'


function findIndex(list, song) {
	return list.findIndex((item) => {
		return item.id === song.id
	})
}

export const selectPlay = function ({commit, state}, {list, index}) {
	commit(types.SET_SEQUENCE_LIST, list)
	if (state.mode === playMode.random) {
		let randomList = shuffle(list)
		commit(types.SET_PLAYLIST, randomList)
		index = findIndex(randomList, list[index])
	} else {
		commit(types.SET_PLAYLIST, list)
	}
	commit(types.SET_CURRENT_INDEX, index)
	commit(types.SET_FULL_SCREEN, true)
	commit(types.SET_PLAYING_STATE, true)
}

export const randomPlay = function({commit}, {list}) {
	commit(types.SET_PLAY_MODE, playMode.random)
	commit(types.SET_SEQUENCE_LIST, list)
	let randomList = shuffle(list)
	commit(types.SET_PLAYLIST, randomList)
	commit(types.SET_CURRENT_INDEX, 0)
	commit(types.SET_FULL_SCREEN, true)
	commit(types.SET_PLAYING_STATE, true)
}

export const insertSong = function({commit, state}, song) {
	let playlist = state.playlist.slice()
	let sequenceList = state.sequenceList.slice()
	let currentIndex = state.currentIndex
	// 记录当前歌曲
	let currentSong = playlist[currentIndex]

	// 查找当前列表中是否有待插入的歌曲并返回其索引
	let fpIndex = findIndex(playlist, song)
	// 因为是插入歌曲，所以索引要+1
	currentIndex++
	// 插入这首歌到当前索引位置
	playlist.splice(currentIndex, 0, song)
	// 如果已经包含这首歌
	if (fpIndex > -1) {
		// 如果当前插入的序号大于列表中的序号
		if (currentIndex > fpIndex) {
			playlist.splice(fpIndex, 1)
			currentIndex--
		} else {
			playlist.splice(fpIndex + 1, 1)
		}
	}

	let currentSIndex = findIndex(sequenceList, currentSong) + 1

	let fsIndex = findIndex(sequenceList, song)

	sequenceList.splice(currentSIndex, 0, song)

	if (fsIndex > -1) {
		if (currentSIndex > fsIndex) {
			sequenceList.splice(fsIndex, 1)
		} else {
			sequenceList.splice(fsIndex + 1, 1)
		}
	}

	commit(types.SET_PLAYLIST, playlist)
	commit(types.SET_SEQUENCE_LIST, sequenceList)
	commit(types.SET_CURRENT_INDEX, currentIndex)
	commit(types.SET_FULL_SCREEN, true)
	commit(types.SET_PLAYING_STATE, true)
}

export const saveSearchHistory = function({commit}, query) {
	commit(types.SET_SEARCH_HISTORY, saveSearch(query))
}

export const deleteSearchHistory = function({commit}, query) {
	commit(types.SET_SEARCH_HISTORY, deleteSearch(query))
}

export const clearSeachHistory = function({commit}) {
	commit(types.SET_SEARCH_HISTORY, clearSearch())
}

小贴士：

默认接口: export default
具名接口: export

1、export导出多个对象，export default只能导出一个对象。

2、export导出对象需要用{ }，export default不需要{ }。

3、在其他文件引用export default导出的对象时不一定使用导出时的名字。因为这种方式实际上是将该导出对象设置为默认导出对象。

4、导入和导出都可以使用as重新命名，as前为原来的名字，后为定义后的名字。
举例：
import * as someIdentifier from "someModule";
***************************************
export { es6 as default } from './someModule';
// 等同于
import { es6 } from './someModule';
export default es6;