GetByUserID as a callback function (express)-CodePudding

A callback function is passed as an argument to another function. In order to respect the separation of concerns, how can I rewrite the following example as a callback? I know that the Req,Res part is outsourced to the router.

Userservice.js

function getByUserId(req, res, next) {

  let userIDD = req.body.userID;
  User.findOne({
    userID: userIDD
  }, function(err, result) {
    if (err) {
      console.log("error: "   err)
    } else {

      console.log("Awesome.");
      res.send(result)
    }
  })
}

UserRoute.js

router.post('/publicUser/getByUserID', userService.getByUserId)

CodePudding user response：

I think it is good now but if you want to use callback and use this function as a middleware you can do next(result) instead of res.send(result)

CodePudding user response：

If you want to declare a callback function directly in your post method you can use an arrow function:

router.post('/publicUser/getByUserID', (req, res) => {
  let userIDD = req.body.userID;
  User.findOne({
    userID: userIDD
  }, function(err, result) {
    if (err) {
      console.log("error: "   err)
      return res.send(err);
    } 

    console.log("Awesome.");
    res.send(result)
  })
})