nodejs 微信开发示例

【核心代码】

'use strict'
var Promise = require('bluebird');//导入这个模块来调用Promise，来实现数据继续往下传
var request = Promise.promisify(require('request'));//因为我们用到了Promise，所以在调用request的时候需要这样导入
var util=require('./util')
var prefix = 'https://api.weixin.qq.com/cgi-bin/';//因为这一部分API是固定的，所以我们单独拿出来
var api = {
    accessToken:prefix 'token?grant_type=client_credential'
}
function Wechat(opts) { //这里面的值就是从中间件传过来的
    var that = this;
    this.appID = opts.appID;
    this.appSecret = opts.appSecret;
    this.getAccessToken = opts.getAccessToken;
    this.saveAccessToken = opts.saveAccessToken;
    //按照上面我们讲的逻辑来实现getAccessToken
    this.getAccessToken()
        .then(function (data) {
            try {
                data = JOSN.parse(data);
            }
            catch(e) {
                return that.updateAccessToken();
            }
            if (that.isValidAccessToken(data)) {
                return Promise.resolve(data);
            }
            else {
                return that.updateAccessToken();
            }
        })
        .then(function (data) {
            that.access_token = data.access_token;
            that.expires_in = data.expires_in;
            that.saveAccessToken(data);
        })
}
//为这个对象添加我们需要的函数
Wechat.prototype.isValidAccessToken = function (data) {
    if (!data || !data.access_token || !data.expires_in) {
        return false;
    }
    var access_token = data.access_token;
    var expires_in = data.expires_in;
    var now = (new Date().getTime())

    if (now < expires_in) {
        return true;
    }else {
        return false;
    }
}
Wechat.prototype.updateAccessToken = function () {
    var appID = this.appID;
    var appSecret = this.appSecret;
    var url = api.accessToken   '&appid='   appID   '&secret='   appSecret;
    return new Promise(function (resolve, reject) {
        request({url: url, json: true}, function (error, response, body) {
            if (!error && response.statusCode === 200) {
                var data = body;
                var now = (new Date().getTime());
                var expires_in = now   (data.expires_in - 20) * 1000;
                data.expires_in = expires_in;
                resolve(data);
                // console.log(data);
            } else {
                reject()
            }
        });
    })
}

Wechat.prototype.reply=function(){
    var content=this.body
    //this.weixin表示的是微信服务器端发送过来的xml解析完成的json数据
    var message=this.weixin
    // console.log('回复给关注者的信息为' content)
    //要回复的xml
    // console.log('message中的值type为' message.type)
    var xml=util.tpl(content,message)
    // console.log('要恢复的xml文件为' xml)
    this.status=200
    this.type='application/xml'
    this.body=xml
    return 
}


module.exports=Wechat