详解在微信小程序的JS脚本中使用Promise来优化函数处理

//app.js
App({
 onLaunch: function () {
 //调用API从本地缓存中获取数据
 var logs = wx.getStorageSync('logs') || []
 logs.unshift(Date.now())
 wx.setStorageSync('logs', logs)
 },
 
 getUserInfo:function(cb){
 var that = this
 if(this.globalData.userInfo){
  typeof cb == "function" && cb(this.globalData.userInfo)
 }else{
  //调用登录接口
  wx.login({
  success: function () {
   wx.getUserInfo({
   success: function (res) {
    that.globalData.userInfo = res.userInfo
    typeof cb == "function" && cb(that.globalData.userInfo)
   }
   })
  }
  })
 }
 },
 globalData:{
 userInfo: null,
 openid: null
 }
})

asyncFunc1(function(){
 //...
 asyncFunc2(function(){
 //...
 asyncFunc3(function(){
  //...
  asyncFunc4(function(){
  //...
  asyncFunc5(function(){
   //...
  });
  });
 });
 });
});

function asyncFunc1(){
 return new Promise(function (resolve, reject) {
 //...
 })
}

const Promise = require('./Promise')

//app.js
const utils = require('./utils/util.js')

App({
 onLaunch: function() {
  //调用API从本地缓存中获取数据
  var logs = wx.getStorageSync('logs') || []
  logs.unshift(Date.now())
  wx.setStorageSync('logs', logs)
 },

 getUserInfo() {
  return new utils.Promise((resolve, reject) => {
   if (this.globalData.userInfo) {
    resolve(this.globalData.userInfo)
   }
   return utils.getUserInfo().then(res => {
    resolve(this.globalData.userInfo = res.userInfo)
   })
  })
 },

 //获取系统信息
 getSystemInfo() {
  return new utils.Promise((resolve, reject) => {
   var that = this
   if (that.globalData.systemInfo) {
    resolve(that.globalData.systemInfo)
   } else {
    wx.getSystemInfo({
     success: function(res) {
      resolve(that.globalData.systemInfo = res);
     }
    })
   }
  })
 },
 //全局对象
 globalData: {
  userInfo: null,
  systemInfo: null
 },
 utils
})

return new utils.Promise((resolve, reject) => {
  
  // 原来的函数体代码 
});

getUserInfo().then(user => this.setData({userInfo:user})).catch(console.log);

//用户登录
function login(){
 return new Promise((resolve,reject) => wx.login({
 success:resolve,
 fail:reject
 }))
}

//获取用户信息
function getUserInfo(){
 return login().then(res => new Promise((resolve,reject) => 
 wx.getUserInfo({
  success:resolve,
  fail:reject
 })
 ))
}

function requstGet(url,data){
 return requst(url,'GET',data)
}

function requstPost(url,data){
 return requst(url,'POST',data)
}

//封装Request请求方法
function requst(url,method,data = {}){
 wx.showNavigationBarLoading()
 data.method = method
 return new Promise((resove,reject) => {
 wx.request({
  url: url,
  data: data,
  header: {},
  method: method.toUpperCase(), // OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, CONNECT
  success: function(res){
  wx.hideNavigationBarLoading()
  resove(res.data)
  },
  fail: function(msg) {
  console.log('reqest error',msg)
  wx.hideNavigationBarLoading()
  reject('fail')
  }
 })
 })
}

//发布的接口
module.exports = {
 Promise,makeArray,getUserInfo,
 get:requstGet,post:requstPost,requst,decodeHtml,

 formatTime,getDateDiff
}

  //使用Comprise的封装函数展现
  var url ='http://localhost:27206/api/Framework/Information/FindByCode';
  var companyurl = "http://www.iqidi.com";
  var json = {code: 'company'};
  app.utils.get(url, json).then(function(res) { 
  var data = { url: companyurl, image: res.Picture, content: res.Content };
  that.setData({
   item : data
  });
  WxParse.wxParse('content', 'html', data.content, that, 25);
  }); 

  // 使用标准的wx.request函数实现展现
  var url ='http://localhost:27206/api/Framework/Information/FindByCode';
  var companyurl = "http://www.iqidi.com";
  var json = {code: 'company'};
  wx.request({
   url: url,
   data: json,
   success: function(res) {
   console.log(res);
   var data = { url: companyurl, image: res.data.Picture, content: res.data.Content };
   that.setData({
    item : data
   });
   WxParse.wxParse('content', 'html', data.content, that, 25);
   }
  })