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RE: Determining attribute uniqueness seems to require namespace prefix in Infoset

From: John Boyer <jboyer@PureEdge.com>
Date: Fri, 11 Aug 2000 13:01:46 -0700
To: "Donald E. Eastlake 3rd" <dee3@torque.pothole.com>
Cc: <xml-names-editor@w3.org>, <www-xml-infoset-comments@w3.org>, "XML DSig" <w3c-ietf-xmldsig@w3.org>
Message-ID: <BFEDKCINEPLBDLODCODKMEEPCEAA.jboyer@PureEdge.com>
Hi Don,

I did not mean to misquote you.  However, I haven't seen any W3C documents,
nor implementations based on them, that use the term 'qualify' as you are
using it.  It is not possible to 'qualify' an attribute with anything but a
namespace URI.

In other words, in the example

<x xmlns:n1="http://www.w3.org" xmlns="http://www.w3.org" >
  <good a="1"     n1:a="2" />
</x>

There does not seem to be any basis in W3C work for the interpretation

1) that 'a' is qualified as (n1:good):a,
2) that 'a' is not qualified by a URI, and
3) that 'a' is qualified by elements, including any URI which may qualify
that element

Therefore, when you said that the attributes "are qualified by their
element", I assumed you meant 'qualify' in the sense defined by XML Names
[1, see the abstract], which associates elements and attributes with a
namespace identified by URI.  With this version of 'qualify', what you said
is equal to what I said you said.

Finally, ending most of our debate about this issue, Tim Bray states, "An
attribute whose name contains no prefix is not in any namespace".  This
means that in the first example of Section 5.2 of XML Names, the href in <a>
is not in the HTML namespace.

This means if I put an HTML island in the middle of some XML by adding
xmlns="http://www.w3.org/TR/REC-html40" to the html tag, then when I want
the href of some anchor, I cannot simply say
'get("http://www.w3.org/TR/REC-html40", href)'.  I must instead say

1) get("http://www.w3.org/TR/REC-html40", href)
2) if that fails, then get("", href)

Once again... Yikes!

John Boyer
Development Team Leader,
Distributed Processing and XML
PureEdge Solutions Inc.
Creating Binding E-Commerce
v: 250-479-8334, ext. 143  f: 250-479-3772
1-888-517-2675   http://www.PureEdge.com <http://www.pureedge.com/>



-----Original Message-----
From: w3c-ietf-xmldsig-request@w3.org
[mailto:w3c-ietf-xmldsig-request@w3.org]On Behalf Of Donald E. Eastlake
3rd
Sent: Friday, August 11, 2000 11:39 AM
To: John Boyer
Cc: xml-names-editor@w3.org; www-xml-infoset-comments@w3.org; XML DSig
Subject: Re: Determining attribute uniqueness seems to require namespace
prefix in Infoset



From:  "John Boyer" <jboyer@PureEdge.com>
To:  <xml-names-editor@w3.org>
Cc:  <www-xml-infoset-comments@w3.org>, "XML DSig" <w3c-ietf-xmldsig@w3.org>
Date:  Fri, 11 Aug 2000 10:15:32 -0700
Message-ID:  <BFEDKCINEPLBDLODCODKOEEKCEAA.jboyer@PureEdge.com>

>Dear Editors,
>
>Please see the first example of Section 5.2 and the sentence immediately
>above it, which says "Note that default namespaces do not apply directly to
>attributes" [1].  One chairman of the XML DSig group recently commented
that
>the word 'directly' may be intended to indicate that unqualified attributes
>inherit their namespace setting from the parent element.  This seems
>sensible to me as the href attribute should be in the same namespace as the
>parent element <a>.

No, I did not say that attributes "inherit their namespace setting
from the parent element".  I said that they are qualified by their
element.  That is, in

<b:a xmlns:b="foo:bar" c="xyz">

it is "as if" c were actually b:a:c except, of course, that this
syntax is illegal.

>[1] http://www.w3.org/TR/REC-xml-names/#defaulting
>
>However, now look at the last example of Section 5.3.  The second occurence
>of <good> has attributes a and n1:a.  This is declared as legal, but if 'a'
>inherits its namespace setting from good, then a and n1:a appear to be
>equal.

But n1:a and n1:good:a would be different.

>...
>
>Could you please advise us on the correct interpretation (and fix the error
>if indeed there is one)?
>
>
>     John Boyer
>      Development Team Leader,
>      Distributed Processing and XML
>      PureEdge Solutions Inc.
>      Creating Binding E-Commerce
>      v: 250-479-8334, ext. 143  f: 250-479-3772
>      1-888-517-2675   http://www.PureEdge.com

Donald
Received on Friday, 11 August 2000 16:02:07 GMT

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