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()
 })
 }
})

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