How to add attributes in predefined metaclasses in magicDraw?

Question

I want to create metamodel based on uml so i need to add attributes at predefined metaclass level like Operation and Parameter but i don't know how, although in a specific article he can add attributes. I tried to build my metamodel based on uml (based on uml metaclasses) I tried to add attributes I found nothing.

Answer 1

I don't think it is possible to add a new attribute to any OOTB stereotype, metaclass, etc. I think you have two options.

1. Create a subclass and add your attribute to the subclass. This is the route to go if the human will populate the attribute directly and you want that attribute to remain persistent on the created element.
2. Use a customization object to add a derived property to the OOTB stereotype, metclass, etc. that will pull information from other existing attributes, related elements, attributes on related elements, etc. to form the new derived property. See the documentation here. This is not like a persistent attribute since it's value(s) must be derived from other existing data, but it can be applied to OOTB metaclasses.