W3C home > Mailing lists > Public > xml-names-editor@w3.org > September 2002

XML Query WG Feedback on Sept WD of Namespaces in XML 1.1

From: Jonathan Robie <jonathan.robie@datadirect-technologies.com>
Date: Wed, 18 Sep 2002 18:05:51 -0400
Message-Id: <5.1.0.14.0.20020918180353.016b5e48@mail.verizon.net>
To: xml-names-editor@w3.org
Cc: w3c-xml-query-wg@w3.org

This is the feedback from the XML Query WG on  Namespaces in XML 1.1, W3C
Working Draft 5 September 2002. We reviewed the diffed version found here:

http://www.w3.org/TR/2002/WD-xml-names11-20020905/WD-xml-names11-20020905-diff.html

Our feedback is as follows:

1. We think it is useful to be able to use empty attribute values to
undeclare namespaces. Some Working Group members, however, are
concerned that the costs to the user community of introducing a new
version exceed the benefits obtained from this change.

2. As the world becomes more open to the world's languages, moving to
IRIs is clearly the right thing to do. The specification does not
state whether processors are required to reject invalid IRIs, and it
should clarify this.

Note: XML 1.0 processors normally do not check for URI validity for
namespace URIs.

3. In the "Conformance of Documents" section, it is very good indeed
that colons can no longer be part of a local name, which has always
been confusing.

4. We dislike the following note:

     Though they are not themselves reserved, it is inadvisable to use
     prefixed names whose LocalPart begins with the letters x, m, l, as
     these names would be reserved if used without a prefix.

It does not clearly state a concern, and the term "inadvisable" is not
clearly defined anywhere - does that mean vendors have to support such
names, issue warnings, or may they decide not to support them? The use of
adjectives without well defined meaning does not lead to an interoperable
world.

5. The namespace spec should say how namespace declarations should map
onto the Infoset. It should distinguish the syntactic form from the
information content in sentences like the following:

      [Definition: A namespace is declared using a family of
      reserved attributes. Such an attribute's name must either
      be xmlns or have xmlns: as a prefix. These attributes,
      like any other XML attributes, may be provided directly or
      by default. ]

The ability to undeclare namespaces creates the possibility of
creating InfoSets that cannot be serialized as XML 1.0. We need to
understand how the InfoSet will tackle this problem: will there be
different InfoSets for XML 1.0 and XML 1.1, or will there be a single
InfoSet with rules for mapping it to both XML 1.0 and 1.1? For the
XPath/XQuery data model, there will clearly be an expectation that
XSLT can be used to convert from 1.0 to 1.1 or vice versa, and
therefore the XPath data model will need to support the union of the
two. Unless the Infoset does the same, it will become difficult to
define the XPath model in terms of the Infoset.

6. The namespace specification either needs to fix namespaces to work
properly with DTDs, or state clearly that they do not.

7. The specification should say what it means for a parser to conform
to the namespace spec - it currently says only what it means for a
document to conform.



Ashok Malhotra, Jonathan Robie
On behalf of the XML Query Working Group
Received on Wednesday, 18 September 2002 18:06:28 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:59:43 GMT