Re: [cgmo-webcgm] Re: namespace convention

[Lofton Henderson <lofton@rockynet.com>]

Many thanks to Robin for the helpful links about RDDL.

(I should warn, that the syntax of RDDL 2.0 is completely different from 
1.0, and you might be confused like I was if you read the 2.0 spec but 
stumble upon 1.0 examples.)

Final questions for Mary...

At 07:56 PM 6/10/2005 -0400, Robin Cover wrote:
>Mary can tell you something more authoritative, but I think the (new)
>OASIS rules will let you put a RDDL Namespace Document at the
>end of the namespace URI, so that you get the RDDL if you
>dereference it.
>
>This is becoming more common now, since the W3C TAG (lightly)
>approved this strategy; see http://xml.coverpages.org/rddl.html

At 11:39 PM 6/10/2005 -0400, Mary McRae wrote:
>Hi Lofton,
>
>   I'm telling you what's in the most recent version of the now-called
>AIR (Artifact Identification Requirements). This document will be
>submitted for member review within a week or two (really, I promise)
>and you can state your case at that point in time for something other
>than what I've quoted. The issue is that we need to have something
>that works for all TCs. Some TCs *want* their namespaces to be
>resolvable; others don't particularly care. As you state below, the
>svg namespace does resolve to something, whether it's the actual
>schema or not. We need to make sure that the location you use *could*
>resolve to something, and to also make sure that it won't resolve to
>something completely unexpected. http://docs.oasis-open.org/webcgm
>will most likely resolve to something - a page that will list all of
>the files/versions of webcgm.
>
>The domain name to be used is either docs.oasis-open.org OR
>cgmopen.org (since it's owned by OASIS).
>
>Spec-id is the official short-name of the specification itself: webcgm
>
>schema is required
>
>schema-filename is the actual name of the schema file (whether it
>resolves or not)

Question.
(1) Must it be a schema file, in the limited sense of XML Schema or RelaxNG 
or similar?
(2) Or could it be an RDDL namespace document (such as last example below)?
(3) Or could it be anything else for that matter?
When you said, "most likely resolve to something - a page that will list 
all of the files/versions of webcgm", I hear "not-necessarily-schema", 
i.e., #2 or even #3 is okay.

>So, valid namespaces would be:
>docs.oasis-open.org/webcgm/schema/XCFschema
>cgmopen.org/webcgm/schema/mySchema
>docs.oasis-open.org/webcgm/schema/WhateverNameYouLike

So these namespace URIs would be valid (correct?) for our present draft 
WebCGM 2.0:

<webcgm xmlns="http://cgmopen.org/schema/webcgm/"; ...>
<webcgm xmlns="http://www.cgmopen.org/schema/webcgm/"; ...>

Those URIs would resolve to nothing ("404 not found" like now), or to 
Index.html if such a file were there.  How about this (acceptable?)...

<webcgm xmlns="http://cgmopen.org/schema/webcgm/webcgmNS-rddl.html"; ...>

(A RDDL document is a modular XHTML document, (optionally) containing two 
extension attributes, rddl:nature and rddl:purpose, for expressing the RDDL 
stuff.)

Regards,
-Lofton.


>Regards,
>
>Mary
>
>
>
>On 6/10/05, Lofton Henderson <lofton@rockynet.com> wrote:
> > I'm still a little confused.  SInce I'm trying to edit the spec now, can
> > you clarify about the URL for the namespace declaration?
> >
> > At 04:00 PM 6/10/2005 -0400, Mary McRae wrote:
> > >[...]
> > >On 6/10/05, Cruikshank, David W <david.w.cruikshank@boeing.com> wrote:
> > > >[...]>
> > > > 1)  url reference for the namespace declaration in our XML DTD - This
> > > one is just a url defining the domain for the namespace.  It doesn't
> > > necessarily even have to resolve, but we might want to put a generic page
> > > in place to explain that it is the namespace domain for WebCGM.  I don't
> > > think this one should be version dependent. It's just declaring the
> > > domain space.
> > > >
> > >URLs or URNs (not both).
> > >
> > >URLs. It will be left to the TC's discretion if there will actually be
> > >something at the other end of a URL namespace.
> > >
> > >The URL namespace will take the form of:
> > >
> > >{oasis domain}/{spec-id}/schema/{schema filename}
> >
> >  From this I gather something like:
> >
> > http://www.oasis-open.org/webcgm/schema/{schema-filename} or
> > http://www.oasis-open.org/webcgm2005/schema/{schema-filename} or
> > http://www.oasis-open.org/webcgmXCF/schema/{schema-filename} or ...
> >
> > I put in the webcgm2005 to illustrate a possibility and a point.  The 2005
> > is not a version, but is basically the year the namespace URL went into
> > use.  It is a convention from my years in W3C.  It is not desired that it
> > be updated for versions, and in fact it is detrimental (to implementors and
> > interoperability) if it is updated for versions.
> >
> > We can live without it (the "2005"), IMO (but I'm not claiming to speak for
> > everyone.)
> >
> > QUESTION.  What is implied by "schema filename"?  Are you saying, if the
> > address resolves to anything, then must resolve to a schema?  We were
> > thinking of doing something like SVG and some other W3C standards.  Its
> > namespace URL is:
> >
> > http://www.w3.org/2000/svg
> >
> > and that resolves to a little HTML document, which contains the W3C logo
> > and the text:
> >
> > >This is an XML namespace defined in the Scalable Vector Graphics (SVG) 1.0
> > >Specification. The latest version can be found http://www.w3.org/TR/SVG.
> > >
> > >For more information about SVG, please refer to the W3C SVG overview. For
> > >more information about XML, please refer to The Extensible Markup Language
> > >(XML) 1.0 specification. For more information about XML namespaces, please
> > >refer to the Namespaces in XML specification.
> >
> > While this little file mentions 1.0, in fact SVG 1.1 and 1.2 all use the
> > same namespace URL, and each of them has a section saying that.
> >
> > As I said, we were thinking -- if the namespace URL resolves at all -- that
> > it should resolve to something like this, and not a schema or dtd.
> >
> > So ... how to wrap this up so that we can have an operational namespace URL
> > asap?
> >
> > Thanks,
> > -Lofton
> >
> >
> >