I think one important part of our being able to migrate AndroMDA from UML
1.4 to UML X.X, or adding support for UML X.X, will depend upon how the
templates are written.

If the templates are written so that they are tightly coupled to the JMI API
of UML 1.4 then we will have a very hard time porting templates.

I therefore believe that patches like:
[Andromda-devel] [ andromda-Patches-763934 ] Implementation of Association
proxy

are appealing in the short term, but they will actually make the porting
much harder and I think it is the opposite direction of where we want to be
headed.

I am not sure who wrote the original DirectionalAssociationEnd in the
SimpleUML for UML2EJB, but I think it was bang on in the right direction.

Let me try to explain.  Let's say that the JMI API for UML 1.4 contains N
classes, where N is a very large number, as in fact it is.  Now imagine we
write a set of templates that in several places directly uses that API so
that eventually the templates are using a very large number of the N classes
of the UML 1.4 JMI API.

In that situation our templates will be very tightly coupled to the UML 1.4
JMI API.  The tight coupling of the templates to JMI will make it extremely
hard to port them to use any other API.

The way to avoid this sort of coupling is to write an isolation layer, or
service/facade layer, that insulates us from the large UML 1.4 metamodel. In
AndroMDA this is our ScriptHelper layer and associated objects like the
DirectionalAssociationEnd.

The Proxy approach, as suggested by this AssociationProxy patch, and as
implemented in the andromda package simpleuml are actually bypassing this
facade layer and increasing template coupling to the underlying JMI api.

If one thinks about it a bit one might imagine this AndroMDA helper facade
parallels somewhat the idea of SessionBeans.  Part of the job of the
SessionBean, putting performance gains aside, is to insulate the application
layer from the specific details of the domain model as implemented by the
EntityBeans.  If the application layer directly uses the EntityBeans then
porting the application to a different domain model implementation becomes
very hard.

So, there is a convenience to using the JMI API directly, but there will be
a big cost later on.  It's a tradeoff that people should be aware of.








> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] Behalf Of Matthias
> Bohlen
> Sent: Wednesday, July 02, 2003 8:18 AM
> To: 'Alexandre Briani Kieling'; [EMAIL PROTECTED]
> Subject: RE: [Andromda-user] UML 1.4, .... UML X.X
>
>
> Hi Alexandre,
>
> good question! I do not have any good answer for it, yet. It looks as if
> there may come a time where some tools will use a new UML metamodel
> (>1.4) and some will stick with 1.4. At that time, we'll have to solve
> the problem using different metamodels with the same generator and
> template set.
>
> New versions of XMI itself are not a problem. These will be handled by
> MDR. (Are you aware that the UML metamodel and XMI/MOF have two
> different version numbers, independent of each other?).
>
> Cheers...
> Matthias
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED] On Behalf
> > Of Alexandre Briani Kieling
> > Sent: Tuesday, July 01, 2003 9:27 PM
> > To: [EMAIL PROTECTED]
> > Subject: [Andromda-user] UML 1.4, .... UML X.X
> >
> >
> > How will AndroMDA keep itself up to date with new UML XMI
> > versions that will be used in the future?
> >
> >
> > On Thu, 26 Jun 2003 17:41:12 -0700, "Anthony Mowers"
> > <[EMAIL PROTECTED]> escreveu:
> >
> > > De: "Anthony Mowers" <[EMAIL PROTECTED]>
> > > Data: Thu, 26 Jun 2003 17:41:12 -0700
> > > Para: "Alexandre Briani Kieling"
> > <[EMAIL PROTECTED]>,
> > <[EMAIL PROTECTED]
> > net>
> > > Assunto: RE: [Andromda-user] Generation process
> > >
> > >
> > > It is not so easy to use UML 1.3 XMI with AndroMDA. UML 1.4 and UML
> > > 1.3 are not identically models.
> > >
> > > The JMI API, upon which the script helper classes are based, was
> > > generated from a MOF  model for UML 1.4.  Therefore the API for
> > > accessing a UML 1.3 model is not the same as the API for
> > accessing a
> > > UML 1.4 model. Therefore the UML1.4 based scripthelpers will almost
> > > certainly not work with a UML 1.3 model.
> > >
> > > Tony
> > >
> > > -----Original Message-----
> > > From: [EMAIL PROTECTED]
> > > [mailto:[EMAIL PROTECTED] Behalf Of
> > > Alexandre Briani Kieling
> > > Sent: Thursday, June 26, 2003 11:51 AM
> > > To: [EMAIL PROTECTED]
> > > Subject: RE: [Andromda-user] Generation process
> > >
> > >
> > > Thanks a lot for your answer, Anthony!
> > > One more question:
> > > I�d like to use AndroMDA with UML 1.3 XMI created by
> > Rational Rose. Is
> > > it only a matter of loading MDR with a MOF model of UML 1.3? If so,
> > > can a use the MOF model available at MDR website
> > > (http://mdr.netbeans.org/metamodels.html) or I will have to
> > create the
> > > MOF 1.3 XMI with Rational Rose?
> >
> > --
> > Alexandre Briani Kieling
> >
> >
> >
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