Hello,
im not a very good developer and i need to make diagrams with (many) customs elements from mysql db and sort them in dropdown list (example below).
Is it possible to modify bpmn to do that ? is it easy, hard, very hard, impossible ? 
If its not possible, maybe can someone give me advices for another library ? thanks !!
Hey Cyrill,
Bpmn-js is easily customizable.
Have a look at here to see how custom elements can be created.