Node Multer unexpected field

Sethe23 picture Sethe23 · Jul 21, 2015 · Viewed 111.1k times · Source

I'm working on uploading a file to my app using the multer npm module.

The multer function I have defined is to allow a single file uploaded to the file system. Everything works during run time; the issue is after I upload the file I get an error below. Any advice appreciated on where to look.

Error:

Unexpected field

Error: Unexpected field
    at makeError (c:\Users\Dev\WebstormProjects\Crunch\node_modules\multer\lib\make-error.js:12:13)
    at wrappedFileFilter (c:\Users\Dev\WebstormProjects\Crunch\node_modules\multer\index.js:39:19)
    at Busboy.<anonymous> (c:\Users\Dev\WebstormProjects\Crunch\node_modules\multer\lib\make-middleware.js:97:7)
    at Busboy.emit (events.js:118:17)
    at Busboy.emit (c:\Users\Dev\WebstormProjects\Crunch\node_modules\multer\node_modules\busboy\lib\main.js:31:35)
    at PartStream.<anonymous> (c:\Users\Dev\WebstormProjects\Crunch\node_modules\multer\node_modules\busboy\lib\types\multipart.js:205:13)
    at PartStream.emit (events.js:107:17)
    at HeaderParser.<anonymous> (c:\Users\Dev\WebstormProjects\Crunch\node_modules\multer\node_modules\busboy\node_modules\dicer\lib\Dicer.js:51:16)
    at HeaderParser.emit (events.js:107:17)
    at HeaderParser._finish (c:\Users\Dev\WebstormProjects\Crunch\node_modules\multer\node_modules\busboy\node_modules\dicer\lib\HeaderParser.js:70:8) 

app.js

var multer = require('multer');
var app = express();
var fs = require('fs');

//. . . 

var upload = multer({ dest: 'upload/'});
var type = upload.single('file');

app.post('/upload', type, function (req,res) {
  var tmp_path = req.files.recfile.path;
  var target_path = 'uploads/' + req.files.recfile.name;
fs.readFile(tmp_path, function(err, data)
{
  fs.writeFile(target_path, data, function (err)
  {
    res.render('complete');
  })
});

Index.hbs

<form action="/upload" method="post" enctype="multipart/form-data">
    <input type="file" name='recfile' placeholder="Select file"/>
    <br/>
    <button>Upload</button>
</form>

#Package.json
  "dependencies": {
    "body-parser": "~1.13.2",
    "cookie-parser": "~1.3.5",
    "debug": "~2.2.0",
    "easy-zip": "0.0.4",
    "express": "~4.13.1",
    "hbs": "~3.1.0",
    "less-middleware": "1.0.x",
    "morgan": "~1.6.1",
    "multer": "~1.0.0",
    "serve-favicon": "~2.3.0"
  }
}

Answer

vincent picture vincent · Jul 22, 2015

The <NAME> you use in multer's upload.single(<NAME>) function must be the same as the one you use in <input type="file" name="<NAME>" ...>.

So you need to change

var type = upload.single('file')

to

var type = upload.single('recfile')

in you app.js

Hope this helps.