Uploading files with Alamofire and Multer

Question

I'm trying to upload image data from iOS using Alamofire to an Express server with Multer. req.file is undefined, and req.body is in the form { file: <bytes> }. There is no error message, but the file does not appear. Here is my code:

var bodyParser = require('body-parser')
var multer = require('multer')

app.use(bodyParser.json())
app.use(bodyParser.urlencoded({ extended: false }))

app.post('/api/photos/upload', function(req, res) {
    var upload = multer({ dest: 'public/images/content/'}).single('file')
    upload(req, res, function(err) {
        if (err) {
            console.log("Error uploading file: " + err)
            return
        }

        // req.file = req.body
        console.log(req.body) // form fields
        console.log(req.file) // form file
    })

    res.json('yeah')
})

On iOS:

let url = fullURL("api/photos/upload")

Alamofire.upload(.POST, url, multipartFormData: { multipartFormData in

        if let image = image {
            if let imageData = UIImageJPEGRepresentation(image, 0.5) {
                multipartFormData.appendBodyPart(data: imageData, name: "file")
            }
        }

        }, encodingCompletion: { encodingResult in

            switch encodingResult {
            case .Success(let upload, _, _):
                upload.responseJSON { response in

                    switch response.result {
                    case .Success:
                        print("success")
                    case .Failure(let error):
                        print(error)
                    }

                }
            case .Failure(let encodingError):
                print(encodingError)
            }

    })

This has puzzled me for hours, any help is greatly appreciated!

UPDATE An HTML form worked fine through the Express endpoint, so it's definitely a problem with the request Alamofire is sending. I've tried a bunch of examples of uploading with Alamofire, but they all send the same incorrect request. There must be a way to make the same request as an HTML form but with Alamofire.

ANOTHER UPDATE
I'm now just using busboy-connect and it's working well, and with a lot more flexibility.

Answer 1

I was just able to get this working. It turns out that you have to specify the fileName and the mimeType using Alamofire in order for multer to pick up the upload on the server end. So, your code for adding the image should look something like this:

if let image = image {
    if let imageData = UIImageJPEGRepresentation(image, 0.5) {
        multipartFormData.appendBodyPart(data: imageData, name: "file", fileName: "fileName.jpg", mimeType: "image/jpeg")
    }
}