Community Users can Upload files from a Flow in the Portal or from the Record Detail related list File Tab. Our goal is to write a Trigger that updates a field whenever a file is uploaded through the Portal. I am pretty new to triggers but don't mind doing the research to figuring out how to make it work. Can anyone point me in the way of a good tutorial to accomplish this???
You will need to write trigger on ContentVersion object. And for checking if file was uploaded in experience cloud, you should be able to use NetworkId field on contentversion. Documentation here. Also use some trigger framework, there are many examples available if you search. Basically there should not be much logic in trigger itself, it should call handler class that should have all the logic.