Use-case extension points

[DionBarrier]

Is there any way to formally associate a given extend relationship with a use-case extension point?  The examples provided simply show a note attached to the relationship line explaining the intention.  Other UML tools I've used allow you to expressly associate an extend relationship with a specific extension point.

[Paul Lotz]

I'm not quite sure what you mean, actually.  There is an "extend" relationship connector in the Use Case toolbox.

Do you mean you want to add a text description to the relationship?

Each relationship has a note compartment, but I don't you can show that on the diagram (although I expect you can show this in an RTF report).  If you want to show the text on a diagram your best bet is to add a Note element to the diagram and link it to one of the elements.

Or are you asking something different?

[DionBarrier]

I think the following link might explain it a bit clearer. http://www.visualcase.com/kbase/use_case_extension_points.htm

[Paul Lotz]

Ah!  That helps!  Now I understand what you want.  (I didn't know about these.)

I see how to create the extension points in EA (http://www.sparxsystems.com/enterprise_architect_user_guide/modeling_languages/extensionpoint.html), but you already know this.

The only thing I can see to do is add a constraint to the extend relationship.  It will then show on the diagram, so the appearance will be similar to the example you gave, but the designer has to type in the extension point.  He can't select it from a list; the relationship is informal.  I don't know of a way to do this more formally.  Yes, it would be good if there was a way!

[Geert Bellekens]

Yes, that seems to be a feature EA is missing.
UML actually defines a relation between the extend relation and the ExtensionPoints.
From UML 2.3 superstructure:

extensionLocation: ExtensionPoint [1..*]
An ordered list of extension points belonging to the extended use case, specifying where the respective behavioral
fragments of the extending use case are to be inserted. The first fragment in the extending use case is associated
with the first extension point in the list, the second fragment with the second point, and so on. (Note that, in most
practical cases, the extending use case has just a single behavior fragment, so that the list of extension points is
trivial.)

I guess you better send in a Feature Request

Geert

[philchudley]

In the meantime, this could be implemented with an Add-In, using the event model to montior the creation of the extends.

I did start something similar a little while, I'll have to dig out my code and update to give the behaviour illustrated here

My Add-In, automatically managed the extension points, so when the extends as created, an associated extension point was created, similarly when Use Cases or extends were deleted.

Cheers

Phil

[DionBarrier]

I've sent in a request referring to this discussion.  

Phil: I've got trade show deadlines I'm running up against presently so I won't have time to do anything right now.  However, if you're willing to share I'd be interested in looking at your add-in.

Thanks,
--Dion