Upload a file in a Multipart form

Upload.swift

struct Uploader {
        static let baseUrl = "YOUR API URL"

        static func multipartBody(filePathKey: String, imageDataKey: NSData, boundary: String) -> NSData {
            let body = NSMutableData();
            
            let filename = "user-profile.jpg"
            let mimetype = "image/jpg"
            
            body.appendString("--\(boundary)\r\n")
            body.appendString("Content-Disposition: form-data; name=\"\(filePathKey)\"; filename=\"\(filename)\"\r\n")
            body.appendString("Content-Type: \(mimetype)\r\n\r\n")
            body.appendData(imageDataKey)
            body.appendString("\r\n")
            body.appendString("--\(boundary)--\r\n")
            
            return body
        }

        
        static func upload(image: UIImage, callback: Result<String> -> ()) {
            
            
            let imageData = UIImageJPEGRepresentation(image, 10)
            let url = NSURL(string: "\(baseUrl)/helpers/upload")!
            
            let request = NSMutableURLRequest(URL:url);
            request.HTTPMethod = "POST";
            
            let boundary = "Boundary-\(NSUUID().UUIDString)"
            
            request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")
            
            if(imageData==nil)  { return; }
            
            request.HTTPBody = self.multipartBody("image", imageDataKey: imageData!, boundary: boundary)
            
            let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
                data, response, error in
                
                if error != nil {
                    callback(.Error(SMBError(code: 0, message: "something went wrong: \(error)")))
                    return
                }
                
                if let data = data{
                    if let imgUrl = JSON(data: data)["img_url"].string {
                        callback(.Value(imgUrl))
                    } else {
                        callback(.Error(SMBError(code: 0, message: "something went wrong: url not found")))
                    }
                    
                }
                
            }
            
            task.resume()
        }
}

enum Result<A> {
    case Error(SMBError)
    case Value(A)
}

/// Very simple error type.
struct SMBError {
    
    /// Error code
    let code : Int
    /// Message
    let message : String
    
    /// Printable message for the logs.
    var debugMessage : String {
        return "an error occured with code: \(code), message: \(message)"
    }

}