xml-dev - Dereferencing a namespace URI {WAS: Success factors for the Web andSeman

[Michael Fitzgerald <mike@wyeast.net>]

In Sean's defense, XML Schema does allow you to "attempt to resolve the
namespace URI to locate such a [schema] resource." It is the last of five
methods for dealing with a validating schema. [*]

Eleven words in an official W3C document. A chink in the armor. A namespace
URI, at least under XML Schema, is more than just an identifier!

Happy holidays,

-Mike

[*] http://www.w3.org/TR/xmlschema-1/#schema-loc (see 1.5)

-----Original Message-----
From: Simon St.Laurent [mailto:simonstl@simonstl.com]
Sent: Thursday, December 21, 2000 3:47 PM
To: XML-Dev Mailing list
Subject: Re: Success factors for the Web and Semantic Web


At 11:32 PM 12/21/00 +0000, Sean Palmer wrote:
>> I don't know what this means.  What is this "language"?  Is it an
>> XML vocabulary/schema?  What is this "correct"?  Is it a matter
>> of authority to use a namespace?
>
>Say I created a namespace for a language at http://infomesh.net/testns/
>Then, on the Web, there are two different XML documents:-
>1. <roota xmlns="http://infomesh.net/testns/"/>
>2. <rootb xmlns="http://infomesh.net/tesns/"/>
>Here, the root elements, (and possibly the enitre definitions of the
>langauges!) are different, but they use the same namespace! Which one is
>definitive? Dereference the namespace, and you might well find out (in this
>case you won't becasue I didn't write a Schema: but I could have done).

Now, why exactly did you think there'd be something definitive at
http://infomesh.net/testns/?

And what exactly do you plan to do when I hand you urn:merde:000000 as a
namespace URI?

And why do you even think we'd have the same flavor of schema lurking at
that URI?

URIs are mush, just identifiers.  That may be why the namespaces spec
doesn't push hard on meanings for dereferencing them.  It might also
suggest that we have the same low expectations for namespaces that we have
for URIs: these critters are _only_ identifiers.

Some days I'd like it to be otherwise, but I've gotten used to that.

Simon St.Laurent
XML Elements of Style / XML: A Primer, 2nd Ed.
XHTML: Migrating Toward XML
http://www.simonstl.com - XML essays and books