UML relationship sides (was Re: How many use the diagram tree?)
From: <ashalper cox net>
To: dia-list gnome org
Subject: UML relationship sides (was Re: How many use the diagram tree?)
Date: Tue, 12 Aug 2003 19:29:09 -0400
> From: Lars Clausen <email@example.com>
> Date: 2003/08/12 Tue AM 01:59:11 EDT
> Not being able to change it would certainly be annoying in a Dia context; I
> guess ERwin doesn't think of connections as first-class citizens, but
> merely an indication that the two entities are related.
Yes. A relationship in IDEF1X or IE is meaningless if there are not attached entities on both ends to relate to.
> Not a behaviour I think we want to copy.
Yes. It's one of those features that would only make sense within the context of certain sheets. I don't really miss it. Sometimes I prefer the Dia interface actually.
One feature I do miss however, is being able to identify which class(es) a particular relationship is attached to by opening the relationship's "Properties" dialog. The "Side A" and "Side B" labels are rather arbitrary and unhelpful IMHO. I was experimenting with a patch to label these based on what class the relationship was attached to, but I got to the point where I realized labeling the "Direction" option field would get very thorny, and I never came up with a good "NULL" label to indicate that the relationship was not attached to anything. On ERwin this not a problem of course, because relationship direction is a fixed property and a relationship always has something attached to both of its endpoints.