> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of Les Munday
> Sent: 08 January 2003 01:54
> To: Dunnavant, Todd; Frank Yang ; E-mail
> Subject: Re: RE: (ROSE) How is Xor-association represented in Rose?
>
>
>
>
> What does it mean when I place an association from a Class A to
> a supertype X with subtypes X1 and X2?
>
> Does it mean that A <-> X1 XOR A<-> X2 ?
It does indeed.
But it may also mean A <-> X, if X is not an abstract class.
>
> If so, is this not a better notation?
If you could generalise from all classes XOR'ed, yes, it would be.
Unfortunately, in some cases, you may end up with fairly unnatural
hierarchies in order to achieve this. So, the cure may be worse than the
illness.
Still, one problem remains with the dependency:
The XOR dependency between associations means nothing to Rose. So, if
code is being generated from the model, either a solution like Les's will
need to be adopted at design time, or some manual coding will need to be
introduced in order to manage and meet the constraint introduced by the
dependency. In either case, a logical-physical model separation appears,
making the model a bit harder to maintain. As these mount up, we end up with
a maintenance nightmare.
In most cases, Les's solution introduced at domain model level will be more
sensible, as long as the generalisation can be made to fit.
Example:
An Application form can be filled by a Person or a Company. Do we have
an Applicant that can be either a Person or a Company, by any chance?
Regards,
H�seyin Angay
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
www.aptprocess.com
any opinions expressed herein are not necessarily those of
the Appropriate Process Movement
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>
> Les.
>
> P.S. Or does it mean A <-> X1 AND A<-> X2 ?
>
> ---- On Tue, 7 Jan 2003, Dunnavant, Todd
> ([EMAIL PROTECTED]) wrote:
>
> > You would place a constraint relation between the
> associations that are
> > being XORed, then label the constraint "XOR", or whatever
> suits your fancy.
> >
>
>
> ________________________________________________
> Get your own "800" number
> Voicemail, fax, email, and a lot more
> http://www.ureach.com/reg/tag
> **************************************************************
> **********
> * Rose Forum is a public venue for ideas and discussions.
> * For technical support, visit http://www.rational.com/support
> * Only plain-text messages are supported.
> * HTML or Rich-Text messages may be rejected.
> *
> * Post or Reply to: [EMAIL PROTECTED]
> * Subscription Requests: [EMAIL PROTECTED]
> * Archive of messages:
> * http://www.rational.com/support/usergroups/rose/rose_forum.jsp
> * Other Requests: [EMAIL PROTECTED]
> *
> * To unsubscribe from the list, please send email
> * To: [EMAIL PROTECTED]
> * Subject: <BLANK>
> * Body: unsubscribe rose_forum
> **************************************************************
> ***********
>
>
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.427 / Virus Database: 240 - Release Date: 06/12/2002
************************************************************************
* Rose Forum is a public venue for ideas and discussions.
* For technical support, visit http://www.rational.com/support
* Only plain-text messages are supported.
* HTML or Rich-Text messages may be rejected.
*
* Post or Reply to: [EMAIL PROTECTED]
* Subscription Requests: [EMAIL PROTECTED]
* Archive of messages:
* http://www.rational.com/support/usergroups/rose/rose_forum.jsp
* Other Requests: [EMAIL PROTECTED]
*
* To unsubscribe from the list, please send email
* To: [EMAIL PROTECTED]
* Subject: <BLANK>
* Body: unsubscribe rose_forum
*************************************************************************
