Unable to validate image using Nodejs Api - Javascript

prabhatmohal
April 18, 2023
215 views
0 votes
2 Answers

I am working with Nodejs and using expressjs framework,Right now i am trying to upload image using Api but
i want two things

1) if image extension is not "jpg,png,gif" then error message should display

Here is my current code

var storage =   multer.diskStorage({
  destination: function (req, file, callback) {
    callback(null, './uploads');
  },
 filename: function (req, file, callback) {
     var sizeOf = require('image-size');
        var sizeOf = require('image-size');
        const originalname = file.originalname;
        const fileExt = originalname.split(".").pop();
       const excatName = originalname.split(".").slice(0, -1).join(".");
       console.log("mimetype is " + file.mimetype); // GETTING FILE EXTENSION NAME
       callback(null, excatName + "-" + Date.now().toString() + "." + fileExt);
      },
});
var upload = multer({ storage: storage }).single('userPhoto');
 const uploadavatar = function (req, res) {
    upload(req,res,function(err) {
        if(err) {
            return res.end("Error uploading file." + err);
        }
        res.end("File is uploaded");
    });
};

Answers

const { promisify } = require('util')
const sizeOf = promisify(require('image-size'))

var upload = multer({
  storage: multer.diskStorage({
      destination: function(req, file, callback) {
          callback(null, './uploads');
      },
      filename: function(req, file, callback) {
          let ogNameArray = file.originalname.split(".");
          callback(null, ogNameArray[0] + "-" + Date.now().toString() + "." + ogNameArray[ogNameArray.length - 1]);
      }
  })
}, {
  fileFilter: (req, file, cb) => {
      const filetypes = /jpeg|jpg|png|gif/;
      const extname = filetypes.test(path.extname(file.originalname).toLowerCase());
      const mimetype = filetypes.test(file.mimetype);
      if(mimetype && extname){ 
        sizeOf('./uploads/' + file.originalname)
        .then(dimensions => { 
          //validate your dimention and return true false based on this
          console.log(dimensions.width, dimensions.height) 
          cb(null, true);
        })
        .catch(err => {
          // invalid file format.
          console.error(err);
          cb(null, false);
        })        
      }else{
        cb(null, false)
      }      
  }
}, ).single('userPhoto');

const uploadavatar = function(req, res) {
  upload(req, res, function(err) {
      if (err) {
          return res.end("Error uploading file." + err);
      }
      res.end("File is uploaded");
  });
};

you can pass a filter function to multer params object and with help of filter you can exclude mimetype and a create a error : –

var storage =   multer.diskStorage({
  destination: function (req, file, callback) {
    callback(null, './uploads');
  },
 filename: function (req, file, callback) {
     var sizeOf = require('image-size');
        var sizeOf = require('image-size');
        const originalname = file.originalname;
        const fileExt = originalname.split(".").pop();
       const excatName = originalname.split(".").slice(0, -1).join(".");
       console.log("mimetype is " + file.mimetype); // GETTING FILE EXTENSION NAME
       callback(null, excatName + "-" + Date.now().toString() + "." + fileExt);
      },
});

 var multerFilter = (req, file, cb) => {
  const memeT = file.mimetype.split('/')[1];
  const restrictToMemeType = ['jpg', 'png', 'gif'];
  if (restrictToMemeType.includes(memeT)) {
    cb(null, true);
  } else {
    cb(new Error('sorry invalid meme type'), false);
  }
};
var upload = multer({ storage: storage,fileFilter: multerFilter }).single('userPhoto');
 const uploadavatar = function (req, res) {
    upload(req,res,function(err) {
        if(err) {
            return res.end("Error uploading file." + err);
        }
        res.end("File is uploaded");
    });
};

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Unable to validate image using Nodejs Api – Javascript

Answers