I'd like to have the Certificate to get the data about attendance from a different table which is in the data base.
Should I change the code ?
If you are using the custom certificate then I would suggest creating another element you can add to the certificate that displays this data.
Thank you Mark for you kind attention.
Do you mean that the possibility to add an element to the certificate that gets values from a speficic table of the Moodle DB is already present in the original plug so I can do it when I add the rest of the elements or that I should create a piece of code (sql, queries, ecc...) on purpose?
You will have to create a new element (located in mod/customcert/element) and add your logic there. It would be great if there was a dev document I could link you to but it doesn't exist.