CODEWITHSUNDEEP
node.jsexpressmulter
Jitendra Pancholi
Jitendra Pancholi

Reputation: 7562

Validation to upload jpg files only in nodejs using multer

I'm using multer to upload files in nodejs. Below is my code.

var multer = require('multer');
var imagefolder = __base + 'public/complaintimages';

var storage = multer.diskStorage({
    destination: function (req, file, cb) {
        if (common.ImageMimeTypes.indexOf(file.mimetype) < 0) {
            common.ActionOutput.Status = common.ActionStatus.Error;
            common.ActionOutput.Message = 'Invalid image file: ' + file.originalname;
            cb(new Error(JSON.stringify(common.ActionOutput)), null);
        } else
            cb(null, imagefolder);
    },
    filename: function (req, file, cb) {
        var filenm = randomstring.generate(10);
        console.log(filenm + file.originalname);
        cb(null, filenm + file.originalname);
    },
    onError: function (err, next) {
        console.log('error', err);
        next(err);
    }
})

var upload = multer({ storage: storage });

I only allowed jpg files to upload by putting the mime type check which is working fine. But when i upload any other type of file, control does not go into onError block so that i can return a proper validation message to the user like 'please upload valid jpg files.' Please advise.

Upvotes: 0

Views: 5102

Answers (1)

Risto Novik
Risto Novik

Reputation: 8295

A different approach for the upload validation, use the fileFilter callback https://github.com/expressjs/multer#filefilter.

It is actually quite complicated to decide what is the file actual type, so instead of using mime type use the (Detect the file type of a Buffer/Uint8Array) https://github.com/sindresorhus/file-type. It's a better approach then deciding based on the mime type, but does not guarantee that it has been faked.

Upvotes: 1

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