Re: Default namespaces and <includes>

Mike_Leditschke@nemmco.com.au writes:

> Thank you for replying Henry.
> 
> I understand (I think) the situation of a reference from the includer
> to the includee - the default namespace definition is
> definitely in scope at that point.
> 
> However, I was thinking more of the reverse case - references
> from the includee to the includer.
> 
> Assume the includee has no namespace declarations but the
> includer does declare a default namespace equal to the
> targetnamespace.
> 
> Does this namespace declaration apply to instances of
> the attributes "type", "base" and "ref" in the includee, and
> if so, is this explicitly covered in the XML Schema spec? If
> it does apply, I don't need to prefix the values of these
> attributes.

Not in the way you put it, no.

I'm sorry I'm not getting this over clearly:  The XML Schema REC
extends the XML Namespace REC to attribute values of type QName in a
_very_ simple way, which is _always_ local to a _single_ XML
document.  On this basis it constructs *expanded names* (written here
in the form {ns or None}local) with respect to which _all_ subsequent
processing is done, including import, include, redefine and
validation.

So the only direct effect a namespace declaration has is on the QName
attributes in scope for that declaration in the infoset in which that
declaration occurs.

> Put another way, if I wish to have the default namespace as the
> target namespace in every included schema, do I have
> to explicitly do this via a default namespace declaration
> within each included schema,

Yes.

> or can I rely on a default
> namespace declaration on the includer?

No.

> The namespace rec says nothing about includes, so I'm
> assuming the include mechanism as defined by XML
> schema results in a single logical XML document against
> which the rules of the namespace rec can be applied.

Absolutely not -- see above.

> I have not put default namespace declarations
> on my included schemas and do have references from the
> includee schemas to the includer, and have not seen errors
> in XSV, Xerces and XMLSpy.

That's because of chameleon processing, I expect, and is a special
feature designed to allow low-level library schema documents declared
without a target namespace to be re-used.  It is independent of the
namespace mechanism as such.  Briefly, it says that when including a
targetless schema into a targetted one, all defs and refs of the form
{None}xxx are turned in to defs and refs of the form {tns}xxx, where
'tns' is the target namespace of the including schema.

Hope this helps.

ht
-- 
  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2001, part-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
		     URL: http://www.ltg.ed.ac.uk/~ht/

Received on Friday, 28 September 2001 08:24:40 UTC