In my project I want to adapt the modeler to proprietary notation which is based on BPMN but has a few different things in the metamodel. I would like to keep away form editing bpmn-moddle. I would rather extend it in some way. The thing I would like to accomplish is to be able to connect datastore to the intermediate message catch event with DataInputAssociation (pointing towards the event, only the opposite direction is available in bpmn).
I have been able to edit the rules so that the connection is possible but I have problems with the custom moddle. Could you please give me a hint of how to crack this thing?