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微信小程序引入es6 promise

更新時(shí)間：2017年04月12日 09:00:10 作者：dzp_coder

本篇文章主要介紹了微信小程序引入es6 promise的相關(guān)知識(shí)。具有很好的參考價(jià)值。下面跟著小編一起來看下吧

微信小程序開發(fā)兩個(gè)月了.大家的項(xiàng)目都在不斷迭代.已經(jīng)不是小程序.這時(shí)候就會(huì)遇到多層回調(diào)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(nèi)測(cè)的時(shí)候promise不需要手動(dòng)引入,后來被微信移除了.看看效果.

promise詳細(xì)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.

1.網(wǎng)絡(luò)請(qǐng)求 wxRequest.js

這里只寫了get和post.

我經(jīng)常會(huì)在網(wǎng)絡(luò)請(qǐng)求的時(shí)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(duì)象最后狀態(tài)如何都會(huì)執(zhí)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(qǐng)求get方法
 * url
 * data 以對(duì)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(qǐng)求post方法封裝
 * url
 * data 以對(duì)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(duì)象最后狀態(tài)如何都會(huì)執(zhí)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(diào)用
 */
function wxGetUserInfo() {
 return wxPromisify(wx.getUserInfo)
}
/**
 * 獲取系統(tǒng)信息
 */
function wxGetSystemInfo() {
 return wxPromisify(wx.getSystemInfo)
}
module.exports = {
 wxPromisify: wxPromisify,
 wxLogin: wxLogin,
 wxGetUserInfo: wxGetUserInfo,
 wxGetSystemInfo: wxGetSystemInfo
}

3.用法

promise應(yīng)用場(chǎng)景很多,下面是promise最基本的用法,在then()中returnpromise對(duì)象.

這樣有效解決了回調(diào)嵌套的問題.讓代碼看起來更優(yōu)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(yīng)用實(shí)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(jī)號(hào)碼
 return wxRequest.postRequest(url, data)
 }).
 then(res => {
 console.log('3.成功了')
 console.log(res)
 //4.獲取系統(tǒng)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?jī)?nèi)容，希望本文的內(nèi)容對(duì)大家的學(xué)習(xí)或者工作能帶來一定的幫助，同時(shí)也希望多多支持腳本之家！