XML Schema for the Simulation Data Model

[Bourgès Laurent]

Hi,

> 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?

As Gerard agrees that UML is the standard IVOA modelling language, I
suggest to complete the SNAP UML model with all possible available details
(descriptions, notes, comments, cardinalities for attributes & collections
...) on entities & diagrams to provide a self consistent document with as
many information as possible.

Then, it will become the source of information on SNAP DM and other
documents (web pages, xml schemas) could be generated from it or for the
moment, updated manually by copy / paste operations (or XSLT if possible).

I want to insist on the hability in UML to provide documentation inside
the description of entities, attributes, relations and so on ...

Maybe, someone could buy a commercial licence of Magic Draw UML which
allow certainly to generate code, xml schemas, documentation ... from a
given UML model. Otherwise, another tools could be chosen which provide
such functionalities.

Q: Any idea ?

I think that it is difficult to gather all previous information from the
word document, discussions, descriptions present in xml schemas but I
think it will clarify the SNAP DM and it is important not to loose the
complete history.

Besides, xml schemas do not contain for now every entities present in the
UML model.

> 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.

Ok, but the word document has a larger scope and a lot of existing content
but is not up to date.

>
> 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.

It is already very useful.

> 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?

I don’t think so. Such tools are useful when coding but lead to confusion
when too many differences occure between 2 versions.

As the SNAP DM is in progress, it is really difficult to find a good way
to track changes, but maybe a simple written change log, as Gerard did, is
enough for the moment.

-------------------------------------------------------------------------
 Laurent Bourgès, engineer
 EURO-VO-DCA Project
 LUTh, Observatoire de Paris-Meudon
 5 place Jules Janssen
 F-92 195 Meudon Cedex
 Email: Laurent.Bourges at obspm.fr
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