xml-dev - UML and XMI (was: RDF or UML)

[Dave Carlson <dcarlson@ontogenics.com>]

----- Original Message -----
From: John F. Schlesinger <johns@syscore.com>
> Sergey wrote (in correspondence with John Borden):
>
> "How would you define a class say Person and serialize an instance
of Person
> in XMI? Maybe I'm missing something..."
>
> XMI is for interchanging metadata, that is models, not for creating
> instances of classes (which would be code). Here is what 6.1 of the
UML 1.3
> specification says (my emphasis):
>
> "The OMG XMI standard specifies a structure for interchanging
_models_ that
> uses XML. The XMI DTD generated for UML is a physical mechanism for
> interchanging UML _models_ conforming to the UML _metamodel_."
>

This quote from the UML spec is accurate for the UML's use of XMI, but
does not capture the full intent of XMI.  XMI can serialize *any*
model for *any* metamodel that is compliant with the MOF.  UML is a
MOF metamodel, but you can create another metamodel and serialize its
model instances using XMI.  The use of XMI by UML is only one special
case of this capability.

One useful way to interpret XMI Toolkit is that it takes a UML model
and "promotes" it to a MOF metamodel, then serializes a model instance
to an XMI file. So, if I create a UML model for a product catalog, I
can read that UML model definition into XMI toolkit and (1) generate a
DTD for the product catalog *metamodel*, and (2) generate an XML
document instance for a product catalog *model* that is valid with
respect to the product catalog DTD.  I have used the IBM's XMI Toolkit
in exactly this way for an example product catalog application.

IBM has also embedded XMI into their SOAP implementation as a way to
serialize Java objects for exchange as content in SOAP messages.

I am debugging a utility that will generate an XML Schema from any UML
model.  It's mostly working and I will post its availability to this
list in the near future.  I am using XSLT for this utility; it's not
dependent on IBM's XMI Toolkit.

> If I have a model that includes the class Person, what I serialize
using XMI
> is the class definition Person (among other things). This allows me,
for
> instance, to store the model in a repository (the MS Repository say)
or to
> import the model into another tool (from Rational Rose to Visual UML
say).
>

Do you know of any way to import an XMI file for a UML model into MS's
Repository?  MS invented their own non-XMI format, called XIF, and I
have not seen any support for importing or exporting XMI from their
repository.

Regards,
  Dave Carlson