ios Upload Image and Text using HTTP POST

Question

Thanks for reading.

I am new to iOS and I am trying to upload an Image and a text using multi-part form encoding in iOS.

The curl

Answer 1

Here is a Swift version. Note that if you do not want to send form data it is still important to send the empty form boundary. Flask in particular expects form data followed by file data and will not populate request.files without the first boundary.

  let composedData = NSMutableData()

  // Set content type header
  let BoundaryConstant = "--------------------------3d74a90a3bfb8696"
  let contentType = "multipart/form-data; boundary=\(BoundaryConstant)"
  request.setValue(contentType, forHTTPHeaderField: "Content-Type")

  // Empty form boundary
  composedData.appendData("--\(BoundaryConstant)\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)

  // Build multipart form to send image
  composedData.appendData("--\(BoundaryConstant)\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
  composedData.appendData("Content-Disposition: form-data; name=\"file\"; filename=\"image.jpg\"\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
  composedData.appendData("Content-Type: image/jpeg\r\n\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
  composedData.appendData(rawData!)
  composedData.appendData("\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)
  composedData.appendData("--\(BoundaryConstant)--\r\n".dataUsingEncoding(NSUTF8StringEncoding)!)

  request.HTTPBody = composedData

  // Get content length
  let length = "\(composedData.length)"
  request.setValue(length, forHTTPHeaderField: "Content-Length")