UML relationship sides (was Re: How many use the diagram tree?)

[<ashalper cox net>]

> From: Lars Clausen <lrclause@cs.uiuc.edu>
> 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.

Andy