Pre-fill a form with attached file taken from some URL in Django
Most sites that do something like this implement it with a second form where you attach the file. Doing the upload via ajax means you do need to store the file on your server for some amount of time, and then your original form just needs a reference to that file so you know when you're done with it.
Then you just need to know when you can delete it.
I have a form with "subject", "body" and "file" fields on some page on my Django site.
If "subject" and/or "body" parameters exist in GET, I pre-fill them in the form from server side.
I want to do the same with "file" field - more exactly, I want if there is an "URL" parameter in request.GET, take the file from this URL and pre-fill the "file" field with it.
I've googled and still have no idea how to implement this whether with pure Javascript or with server-side help, and from my experience, it isn't possible (or at least hard to do) in most browsers due to input type="file" nature.
Is it in fact possible to implement it in some way?