微信小程序開發兩個月了.大家的項目都在不斷迭代.已經不是小程序.這時候就會遇到多層回調嵌套的問題.有些目不忍視了.迫不得已引入es6-promise.在微信小程序內測的時候promise不需要手動引入,后來被微信移除了.看看效果.
promise詳細的介紹我就不說了.有很多大神寫過.
看看目錄,引入es6-promise就可以用了.
目錄
1.網絡請求 wxRequest.js
這里只寫了get和post.
我經常會在網絡請求的時候用微信原生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) { //失敗 reject(res) } fn(obj) }) }}//無論promise對象最后狀態如何都會執行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 }) );};/** * 微信請求get方法 * url * data 以對象的格式傳入 */function getRequest(url, data) { var getRequest = wxPromisify(wx.request) return getRequest({ url: url, method: 'GET', data: data, header: { 'Content-Type': 'application/json' } })}/** * 微信請求post方法封裝 * url * data 以對象的格式傳入 */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) { //失敗 reject(res) } fn(obj) }) }}//無論promise對象最后狀態如何都會執行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 }) );};/** * 微信用戶登錄,獲取code */function wxLogin() { return wxPromisify(wx.login)}/** * 獲取微信用戶信息 * 注意:須在登錄之后調用 */function wxGetUserInfo() { return wxPromisify(wx.getUserInfo)}/** * 獲取系統信息 */function wxGetSystemInfo() { return wxPromisify(wx.getSystemInfo)}module.exports = { wxPromisify: wxPromisify, wxLogin: wxLogin, wxGetUserInfo: wxGetUserInfo, wxGetSystemInfo: wxGetSystemInfo}3.用法
promise應用場景很多,下面是promise最基本的用法,在then()中returnpromise對象.
這樣有效解決了回調嵌套的問題.讓代碼看起來更優雅.可讀性更高.
var util = require('../../utils/util')var wxApi = require('../../utils/wxApi')var wxRequest = require('../../utils/wxRequest')import config from '../../utils/config'//獲取應用實例var app = getApp()Page({ data: { userInfo: {} }, onLoad: function () { var that = this; wx.showToast({ title: '加載中', icon: 'loading', duration: 10000 }) //1.獲取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.獲取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.獲取綁定手機號碼 return wxRequest.postRequest(url, data) }). then(res => { console.log('3.成功了') console.log(res) //4.獲取系統信息 var wxGetSystemInfo = wxApi.wxGetSystemInfo() return wxGetSystemInfo() }). then(res => { console.log('4.成功了') console.log(res) //5.獲取用戶信息 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內容，希望本文的內容對大家的學習或者工作能帶來一定的幫助，同時也希望多多支持武林網！
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