Use nodejs+redis+mysql to develop WeChat QR code polling interface

Introduction: How does the client know when the user scans the code? Develop polling interface

• process
  
• Create polling interface

  http://127.0.0.1:8081/api/wx_login/v1/checkScan
  
  请求方法：get
  请求参数：ticket
  

  • Add an interface path to the wxLogin.js file in the router file of the project

    const wxLoginController = require('../controller/WxLoginController')
    // 轮询用户是否扫码
    router.get('/checkScan',wxLoginController.checkScan)
    

  • Receive the data passed by the front-end call interface at the control layer, and return it to the front-end after processing

    const WxLoginService = require('../service/WxLoginService')
    
      checkScan: async (req,res)=>{
            
            
        let handleRes = await WxLoginService.checkScan(req)
        res.send(handleRes)
      }
    }
    

    • In the data layer, query whether the isScan field of the redis cache is changed to yes. If so, it means that the user has already scanned the code, and then returns the token to the front end for storage. If not, it prompts the front end to wait for the user to scan the code.

    const redisConfig = require("../config/redisConfig");
    const BackCode = require("../utils/BackCode");
    const CodeEnum = require('../utils/CodeEnum')
    
    checkScan: async (req) => {
            
            
      let {
            
            ticket} = req.query
      let key = `wechat:ticket:${
              
              ticket}`
      let redisData = JSON.parse(await redisConfig.get(key))
      if(redisData && redisData.isScan == 'yes') {
            
            
        let {
            
            token} = redisData
        return BackCode.buildSuccessAndData({
            
            data:`Bearer${
              
              token}`})
      }else {
            
            
        return BackCode.buildResult(CodeEnum.WECHAT_WAIT_SCAN)
      }
    },
    

• Thanks to the high level, you can test the interface on APIFOX, the interface address: /api/wxLogin/v1/checkScan