stop the file upload in multer if the user validation fails

Question

The file uploading is done by multer by using this code, but how to stop the file upload when the user validation fails. where to write the user validation part in this code

router.post('/profilePicture',
 multer({dest: './uploads/',
rename: function (fieldname, filename,req,res) {
      return image = req.body.userId+'-'+dateTime+'-'+randomId();
    },
    onFileUploadStart: function (file,req,res) {
        if(file.mimetype !== 'image/jpg' && file.mimetype !== 'image/jpeg' && file.mimetype !== 'image/png') {
          imageUploadDone = false;
          return false;
        }
        //console.log(file.originalname + ' is starting ...');
    },
    onFileUploadComplete: function (file,req,res) {
      //console.log(file.fieldname + ' uploaded to  ' + file.path);
      if(file.mimetype == 'image/jpg')
        extn  = '.jpg';
      if(file.mimetype == 'image/jpeg')
        extn  = '.jpeg';
      if(file.mimetype == 'image/png')
        extn  = '.png';
      imageUploadDone=true; 
    }
}),function(req, res) { 
      upload(req,res,function(err) {
    if(imageUploadDone==true){
      //console.log(image);
      var userInfo = {'userId':req.body.userId,'newImage':address+image+extn,'path':'./uploads/'};
          db.profilePicture(userInfo,function(result){
            if(result.message == 'image path added'){
              res.json({'success':'1','result':{'message':'Profile Picture Updated','imageUrl':address+image+extn},'error':'No Error'});
            }
          });
    }
    if(imageUploadDone == false){
    res.json({'success':'0','result':{},'error':'file format is not supported'});
  }
  });
});

i try to validate the user on the events like onFileUploadStart and onFileUploadComplete. if user is not valid still the file gets uploaded to the path.

Answer 1

This is now possible in 1.0.0.

If you want to abort the upload:

multer({
      fileFilter: function (req, file, cb) {
         if (path.extname(file.originalname) !== '.pdf') {
                 return cb(new Error('Only pdfs are allowed'))
          }

         cb(null, true)
       }
 })

If you want to skip any files that is not pdf:

multer({
      fileFilter: function (req, file, cb) {
          if (path.extname(file.originalname) !== '.pdf') {
                  return cb(null, false)
       }

      cb(null, true)
      }
 })