@markarupert. Sorry for not responding sooner. Ok… You may need to explain more of what you are trying to do. However, if you have a look at the helper.php file around line 201, you will see a function called: storeUploadedFile. In that function, you will see how I get the file name from the $_FILES variable. Because it is a multipart/form-data, the file data, including the name, is stored in the php variable $_FILES.
Let me know if this helps.