What are these in the UML Class Diagram?

Question

I'm studying Enterprise Architect.

Abstract means being abstract Is Root means top-level parent class Is Leaf means no more children

But I still don't know Is Specification, is Active. The documentation I found defined it this way I don't know what this means. Is Specification : Select the checkbox to identify the element as being a specification. is Active : Select the checkbox to identify the element as being an Active Class.

Who can answer me?

Answer 1

Active classes is about concurrency. The instances of these classes have each their own thread of execution/control, and run potentially at the same time. More precisely, according to the UML specification:

An active object is an object that, as a direct consequence of its creation, commences to execute its classifierBehavior, and does not cease until either the complete Behavior is executed or the object is terminated by some external object. (This is sometimes referred to as “the object having its own thread of control.”)

The Is Specification as property is obsolete. It dates back to UML 1.4 and was used to indicate if an owned element was part of the specification of the owning element or if it was not part of the specification and only relevant for the realization (implementation). In the current version of UML, there is no longer the isSpecification property. The only «Specification» left is a stereotype for components to be able to distinguish them from «Realization» components, but this should be modelled in EA with stereotypes and not using this property.