Re: Question on xsd:import

On Tue, 16 Sep 2003 03:11:09 -0700
Martin Gudgin <mgudgin@microsoft.com> wrote:
> This text first appeared in wsdl12.xml CVS revision 1.34.2.2 as part
> of the types work ( it was subsequently merged into the main branch in
> version 1.35 ). It was part of the write up that Amy did, I think.
> Note that this ONLY applies to schemas that DO NOT have a target
> namespace. It cannot be used to override the namespace of an imported
> schema document that DOES have a target namespace. The text
> essentially means that all schemas constructs are qualified. I can't
> remember the rationale for allowing this, perhaps Amy will have better
> powers of recall.

As I recall, this deals with XML Schemas that were originally designed
for use as "chameleons", and it also provides a pattern for use with
other schema languages (for instance, the DTD example uses a similar
technique to place all of the elements imported into a single
namespace).

As Gudge says, I believe that this is simply intended to force schemas
lacking namespaces into a namespace.  The principle is simplicity: if
you're going to refer to components of a schema by namespace, it ought
to be the same as the namespace that labels the import.  But I believe
the language was specifically chosen to avoid allowing chameleons.

Amy!
> I would note that this text was reviewed as part of the types work in
> January 2003 and was agreed by the WG. That said, I don't feel
> strongly about it and would be happy for us to open an issue to
> claridy this point.
> 
> Gudge
> 
> > -----Original Message-----
> > From: www-ws-desc-request@w3.org 
> > [mailto:www-ws-desc-request@w3.org] On Behalf Of Roberto Chinnici
> > Sent: 16 September 2003 01:06
> > To: www-ws-desc@w3.org
> > Subject: Question on xsd:import
> > 
> > 
> > It's been about a year since we last talked about imports. In
> > section 3.1.1.1 of part 1 of the spec I found this sentence 
> > describing how xsd:import works (the text in square brackets is
> > mine):
> > 
> > "If the [imported] schema does not have a targetNamespace 
> > AII, then the namespace specified by the namespace AII [of 
> > the xsd:import EII inside the wsdl:type EII] is applied to 
> > all components of the schema as if it contained a 
> > corresponding targetNamespace declaration."
> > 
> > This looks very different from what XML Schema does. It seems 
> > that to honor this clause a WSDL processor would need to use 
> > a specially rigged XML Schema processor that allows for this 
> > namespace overriding to happen.
> > 
> > Can someone refresh my memory as to when we approved the text 
> > above and what its rationale was?
> > 
> > Thanks,
> > Roberto
> > 
> > --
> > Roberto Chinnici
> > Java Web Services
> > Sun Microsystems, Inc.
> > roberto.chinnici@sun.com
> > 
> > 
> > 
> 


-- 
Amelia A. Lewis
Architect, TIBCO/Extensibility, Inc.
alewis@tibco.com

Received on Tuesday, 16 September 2003 12:42:29 UTC