微信小程序 引入es6 promise

微信小程序开发两个月了.大家的项目都在不断迭代.已经不是小程序.这时候就会遇到多层回调嵌套的问题.有些目不忍视了.迫不得已引入es6-promise.在微信小程序内测的时候promise不需要手动引入,后来被微信移除了.看看效果.

 

promise详细的介绍我就不说了.有很多大神写过.

看看目录,引入es6-promise就可以用了.

 

目录

1.网络请求 wxrequest.js

这里只写了get和post.

我经常会在网络请求的时候用微信原生showtoast(),所以最后加了finally,方便hidetoast()

var promise = require('../plugins/es6-promise.js')

function wxpromisify(fn) {
 return function (obj = {}) {
 return new promise((resolve, reject) => {
 obj.success = function (res) {
 //成功
 resolve(res)
 }
 obj.fail = function (res) {
 //失败
 reject(res)
 }
 fn(obj)
 })
 }
}
//无论promise对象最后状态如何都会执行
promise.prototype.finally = function (callback) {
 let p = this.constructor;
 return this.then(
 value => p.resolve(callback()).then(() => value),
 reason => p.resolve(callback()).then(() => { throw reason })
 );
};
/**
 * 微信请求get方法
 * url
 * data 以对象的格式传入
 */
function getrequest(url, data) {
 var getrequest = wxpromisify(wx.request)
 return getrequest({
 url: url,
 method: 'get',
 data: data,
 header: {
 'content-type': 'application/json'
 }
 })
}

/**
 * 微信请求post方法封装
 * url
 * data 以对象的格式传入
 */
function postrequest(url, data) {
 var postrequest = wxpromisify(wx.request)
 return postrequest({
 url: url,
 method: 'post',
 data: data,
 header: {
 "content-type": "application/x-www-form-urlencoded"
 },
 })
}

module.exports = {
 postrequest: postrequest,
 getrequest: getrequest
}

2.微信其他api wxapi.js

var promise = require('../plugins/es6-promise.js')

function wxpromisify(fn) {
 return function (obj = {}) {
 return new promise((resolve, reject) => {
 obj.success = function (res) {
 //成功
 resolve(res)
 }
 obj.fail = function (res) {
 //失败
 reject(res)
 }
 fn(obj)
 })
 }
}
//无论promise对象最后状态如何都会执行
promise.prototype.finally = function (callback) {
 let p = this.constructor;
 return this.then(
 value => p.resolve(callback()).then(() => value),
 reason => p.resolve(callback()).then(() => { throw reason })
 );
};
/**
 * 微信用户登录,获取code
 */
function wxlogin() {
 return wxpromisify(wx.login)
}
/**
 * 获取微信用户信息
 * 注意:须在登录之后调用
 */
function wxgetuserinfo() {
 return wxpromisify(wx.getuserinfo)
}
/**
 * 获取系统信息
 */
function wxgetsysteminfo() {
 return wxpromisify(wx.getsysteminfo)
}
module.exports = {
 wxpromisify: wxpromisify,
 wxlogin: wxlogin,
 wxgetuserinfo: wxgetuserinfo,
 wxgetsysteminfo: wxgetsysteminfo
}

3.用法

promise应用场景很多,下面是promise最基本的用法,在then()中returnpromise对象.

这样有效解决了回调嵌套的问题.让代码看起来更优雅.可读性更高.

var util = require('../../utils/util')
var wxapi = require('../../utils/wxapi')
var wxrequest = require('../../utils/wxrequest')
import config from '../../utils/config'
//获取应用实例
var app = getapp()
page({
 data: {
 userinfo: {}
 },
 onload: function () {
 var that = this;
 wx.showtoast({
 title: '加载中',
 icon: 'loading',
 duration: 10000
 })
 //1.获取code
 var wxlogin = wxapi.wxlogin()
 wxlogin().then(res => {
 console.log('1.成功了')
 console.log(res.code)
 var url = config.getopenidurl;
 var params = {
 appid: "wxed7******2d465",
 secret: "e9c5e4c******09ecc5ebd811",
 js_code: res.code,
 grant_type: "authorization_code"
 }
 //2.获取openid
 return wxrequest.getrequest(url, params)
 }).
 then(res => {
 console.log('2.成功了')
 console.log(res)
 var url = app.globaldata.ip + config.searchdgurl
 var data = util.json2form({ phonenumber: '15971908021' })
 //3.获取绑定手机号码
 return wxrequest.postrequest(url, data)
 }).
 then(res => {
 console.log('3.成功了')
 console.log(res)
 //4.获取系统信息
 var wxgetsysteminfo = wxapi.wxgetsysteminfo()
 return wxgetsysteminfo()
 }).
 then(res => {
 console.log('4.成功了')
 console.log(res)
 //5.获取用户信息
 var wxgetuserinfo = wxapi.wxgetuserinfo()
 return wxgetuserinfo()
 }).
 then(res => {
 console.log('5.成功了')
 console.log(res.userinfo)
 that.setdata({
  userinfo: res.userinfo
 })
 })
 .finally(function (res) {
 console.log('finally~')
 wx.hidetoast()
 })
 }
})

以上就是本文的全部内容，希望本文的内容对大家的学习或者工作能带来一定的帮助，同时也希望多多支持！