Access multipart/form-data information

I am trying to create a script to upload a file to another service through DreamFactory. I need to send the file to the other service (Python-Eve) using multipart/form-data, but I would like to check parts of the data first. I have created a custom server-side script (PHP), but cannot seem to access any of the data - $event[‘request’][‘payload’] is an empty array and $event[‘request’][‘content’] is an empty string.

How to upload a file using custom script? and File upload and custom script service seem to suggest that it isn’t possible, is this still the case? It would be really beneficial to be able to upload files to custom scripts