Hi all,
EA lets me draw object flows between actions or action pins and instances of classes (objects). This is useful for when you want to show the object states explicitly in your activity diagram.
But if I make an instance of an artifact, EA says the requested connection is not UML compliant. Why is this?
I can work around it and force EA to accept this construction. That's not the question. The question is, why does UML say I should not make instances of artifacts and have them be the endpoints of object flows, like I can with instances of classes?
/Uffe
It may be because Artifacts are
always instances. Recall my recent question on what is an instance? I've now come to the conclusion that some kinds of things are inherently at the instance level. Actors, for example. We have specific actors, me, you, and we have placeholder actor "Sparx EA User" - all are instances, the later a placeholder for an eventual specific instance that can "fit the bill" at runtime.
I'm now not sure, in a modelling sense, if there is actually a valid concept as the aggregate Actor "Sparx EA Users", but I remain open-minded. I believe we colloquially use the term "Sparx EA Users" when we mean the singular placeholder.
HTH,
Paolo