Custom certificate (plugin)

It doesn't look like this is possible. You can add values for the fields specified when adding a certificate to a Moodle course, but from what I could understand of the PHP code, you can't add you own fields ... interactive or otherwise.

Interesting idea though!
Gordon

What is possible :

Somebody with php knowledge can modify your certificate code so that questions are asked before certificate issue and the answers to this questions used on certificate printing.

The problem is that to do that you will need to modify files outside of the /type subfolder of the certificate folder. And later when you would want to upgrade to a new certifictae version you would have to redo the changes at each upgrade.

My opinion is that creating new certificates types (new subfolders in the /type subfolder) or adding new images in the /pix subfolder is safe because you can still upgrade your certificate mod later. But my advice is to avoid any modification outside of the /type and /pix subfolders because future upgrades will become a real pain.

Or : 2nd solution

You can't create a pdf (interactive or not) with some pdf creator software (like Adobe acrobat) and use that pdf during your certificate creation.

The reason is that the TCPDF library that certificate module use to create the pdf is not able to do that.

But there are other existing libraries (like FPDI + TCPDF or Zend PDF) that can merge several pdf. So here also a programmer should be able to create a modified certificate suiting your needs.

As always with computer programming, nearly everything is possible ... with a good programmer (and the money to pay him).

Please when you start such customized developpment, don't forget that later it will need some maintenance !!