req.body undefined multipart

Question

I have a problem with my POST request on multipart (form-data). All ideas in other topics don't work.

I use express, multer and postman
I totally delete body-parser
Uploading files works but accessing the data with a key don't work.
When I try console.log(req.body); I obtain undefined

This is my code:

app.js


    var express = require('express');
    var path = require('path');
    var favicon = require('serve-favicon');
    var logger = require('morgan');
    var cors=require('cors');

    //var index = require('./routes/index');
    //var users = require('./routes/users');
    var UsersDB=require('./routes/UsersDB');

    var app = express();

    // view engine setup
    app.set('views', path.join(__dirname, 'views'));
    app.set('view engine', 'jade');

    // uncomment after placing your favicon in /public
    //app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
    app.use(cors());
    app.use(logger('dev'));
    app.use(express.static(path.join(__dirname, 'public')));

    //app.use('/', index);
    //app.use('/users', users);
    app.use('/Users',UsersDB);

    // catch 404 and forward to error handler
    app.use(function(req, res, next) {
      var err = new Error('Not Found');
      err.status = 404;
      next(err);
    });

    // error handler
    app.use(function(err, req, res, next) {
      // set locals, only providing error in development
      res.locals.message = err.message;
      res.locals.error = req.app.get('env') === 'development' ? err : {};

      // render the error page
      res.status(err.status || 500);
      res.render('error');
    });


    module.exports = app;

UsersDB.js


    var express = require('express');
    var router = express.Router();
    var Users=require('../models/Users');
    var multer = require('multer');

    var storage = multer.diskStorage({
      destination: function (req, file, cb) {
        cb(null, './uploads')
      },
      filename: function (req, file, cb) {
        cb(null, file.fieldname + '-' + Date.now() + ".png")
      }
    });

    var upload = multer({ storage: storage }).single('avatar');


    //** POST **  ROUTE : http://localhost:3000/Users/       
    router.post('/',function(req,res,next)
    {
        console.log(req.body.firstName);

    /*
        Users.addUsers(req.body,function(err,count)
        {
            if(err)
            {
                res.json(err);
            }
            else
            {
                res.json(req.body);//or return count for 1 &amp;amp;amp; 0
            }
        });
    */
        upload(req, res, function (err) {
        if (err) {
          // An error occurred when uploading
          return
        }
        // Everything went fine
      })

    });

    module.exports=router;

Error on Postman:


    <!DOCTYPE html>
    <html>
        <head>
            <title></title>
            <link rel="stylesheet" href="/stylesheets/style.css">
        </head>
        <body>
            <h1>Cannot read property 'firstName' of undefined</h1>
            <h2></h2>
            <pre>TypeError: Cannot read property 'firstName' of undefined
        at /mnt/c/Users/Elodie/Desktop/server/routes/UsersDB.js:69:25
        at Layer.handle [as handle_request] (/mnt/c/Users/Elodie/Desktop/server/node_modules/express/lib/router/layer.js:95:5)
        at next (/mnt/c/Users/Elodie/Desktop/server/node_modules/express/lib/router/route.js:137:13)
        at Route.dispatch (/mnt/c/Users/Elodie/Desktop/server/node_modules/express/lib/router/route.js:112:3)
        at Layer.handle [as handle_request] (/mnt/c/Users/Elodie/Desktop/server/node_modules/express/lib/router/layer.js:95:5)
        at /mnt/c/Users/Elodie/Desktop/server/node_modules/express/lib/router/index.js:281:22
        at Function.process_params (/mnt/c/Users/Elodie/Desktop/server/node_modules/express/lib/router/index.js:335:12)
        at next (/mnt/c/Users/Elodie/Desktop/server/node_modules/express/lib/router/index.js:275:10)
        at Function.handle (/mnt/c/Users/Elodie/Desktop/server/node_modules/express/lib/router/index.js:174:3)
        at router (/mnt/c/Users/Elodie/Desktop/server/node_modules/express/lib/router/index.js:47:12)</pre>
        </body>
    </html>

score 5 · Accepted Answer · answered Jun 30 '17 at 16:17

Since you're using multer to parse the request body, you're going to need to invoke multer prior to accessing req.body. The way you are currently using multer, it will extract the information from the request to process the file but will not be part of the middleware stack so you don't get the benefit of the body parsing prior to your route being called.

Add the multer middleware into the route signature and so it the request body will be parsed by multer prior to the route callback being invoked. For example like this

router.post('/', upload.single('avatar'), (req, res, next) => {
  console.log(req.body.firstName)
})

req.body undefined multipart

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