Unable to use filefilter to redirect other page in express js

Question

var express = require('express');
var router = express.Router();
var multer = require('multer');
var storage = multer.diskStorage({
    destination: function (req, file, cb) {
        cb(null, 'public/uploads/');
    },
    filename: function (req, file, cb) {
        cb(null, file.originalname);
    }
});
var upload = multer({
    storage: storage, fileFilter: function (req, file, cb) {
        if (file.mimetype !== 'image/png' && file.mimetype !== 'image/jpg' && file.mimetype !== 'image/jpeg') {
            return cb(null, false);
        }
        return cb(null, true);
    }
}).any();



/* get home page. */
router.get('/', function (req, res) {
    res.render('index', { title: 'express' });
});

router.post('/', function (req, res) {
    upload(req, res, function (err) {
        if (err) {
            //I want to jump to another page
        } else {
            res.send(req.files);
        }
    });    
});


module.exports = router;

In if (err) condition I want to redirect the page I created under views folder, its's called wrong. However, if I use res.redirect('wrong') or res.redirect('views/wrong'), they just didn't work. Actually I tried a lot of methods but all of them didn't work. If I upload the file but not a picture, it will jump to a page with one '[]' in it. How can I do redirect?

Answer 1

You could use something like this:

router.post('/', function (req, res) {
    upload(req, res, function (err) {
        if (err) {
            res.redirect('/?error=upload_error');
        } else {
            res.send(req.files);
        }
    });    
});

Use upload_error in your page to show the error.

Answer 2

I get an alternative. In this case it can show the wrong message if you upload wrong type file.

var express = require('express');
var router = express.Router();
var multer = require('multer');
var storage = multer.diskStorage({
    destination: function (req, file, cb) {
        cb(null, 'public/uploads/');
    },
    filename: function (req, file, cb) {
        cb(null, file.originalname);
    }
});
var upload = multer({
    storage: storage, fileFilter: function (req, file, cb) {
        if (file.mimetype !== 'image/png' && file.mimetype !== 'image/jpg' && file.mimetype !== 'image/jpeg') {
            req.fileValidationError = 'goes wrong on the mimetype';
            return cb(null, false, new Error('goes wrong on the mimetype'));
        }
        return cb(null, true);
    }
}).any();



/* get home page. */
router.get('/', function (req, res) {
    res.render('index', { title: 'express' });
});

router.post('/', function (req, res) {
    upload(req, res, function (err) {
        if (req.fileValidationError) {
            //I want to jumpt to another page
            res.send("You didn't upload a valid pic");
        } else {
            res.send(req.files);
        }
    });    
});


module.exports = router;