XML Schema for the Simulation Data Model

[Gerard]

Hi Rick (and Laurent) and other readers
I pose some questions to the community below, please all give your comments.


> Rick wrote: 
> I'm still going through your entire response, but I realized that
> this statement made it possible for me to make a concrete design
> suggestion for the model:

That is a good approach and I was going to add your suggestion+motivation to
the wiki when I saw in a later email that you were goig to do so yourself.
I will add my suggestion for the way to support this in the model on that
same page.
> 

Answers to Laurent:
About the SNAP document. I am trying to port the current document to the
wiki page, at least for documenting the individual modeling elements.
This could take the place of the word document. 

Q: Does anyone have any objections to that?

I agree completely that UML should be the standard (UML was endorsed almost
5 years ago as the standard to be used for data models by the DM WG) and
that we should be able to define rules for automatically translating
(properly constrainted) UML to XML schema (see
http://www.ivoa.net/internal/IVOA/VOResource010RevNotes/ModelBasedSchema.ppt
for a presentation I once gave on the subject for the registry group). 
I wrote an XMI-to-XSD(and Java and Hibernate) translator script in XSLT
years ago. It used XMI 1.0, and XMI 2 (used by Magic Draw ) is very
different and the scripts will not work. 
There are tools to assist in this task, in particular Googling on
openarchitectureware will lead you to one of these, used by the ALMA project
for this same reason. Norman Gray wrote an XSLT script last year to
translate XMI documents to RDF, maybe we can modify those to produce XSD.

Until we have automated translation in place, I have tried to adhere to the
mapping rules expressed in the presentation, which could/should be
formalized. I think that the task to come up with such a definition really
belongs to the DM WG's domain and I have various times suggested this as an
action to them, but so far without effect. 

Q: Mireile, how should we proceed to get this done?

On change tracking:
I have started trying to keep a change log on the new UML data models on the
wiki, which is likely not optimal. Advantage of this is that it is open to
everyone. 

Rick wrote:
> I think the start of a solution to what you're suggesting a version 
> control system (Subversion gets my vote), and perhaps something like a 
> Trac site. This would give easy access to a change log, and a way to 
> compare versions. Both the NVO and AstroGrid use Trac and Subversion, so I

> suspect someone would host the project. If not, I will offer up space on 
> our server.

Q: Do we need a proper system as Rick suggests?

Best regards

Gerard Lemson