Automating the request and receipt of a file from the site?

Question

Web development

Task:
Automate a request sent by a user through a form on a site and receiving a file from the site.
The file may be pdf, may be xml.
Tell me where to start?
What is the best way to process xml?

Answer 1

Tell me where to start?

Decide on 2 things:
- how to determine whether pdf is still or xml
- what does it mean to process?
If we are talking about saving - then what's the difference between pdf and xml? If you need to pull out data, then these are two completely different stories, one about pdf, the other about xml. But in any case, at least briefly describe what kind of data is expected, since in my opinion pdf or xml should contain completely different data and it is not clear why the user sends them through the same form to the same action.