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[Bug 4523] Default Unprefixed Namespace Handling is Problematic

From: <bugzilla@wiggum.w3.org>
Date: Wed, 02 May 2007 23:24:56 +0000
CC:
To: public-qt-comments@w3.org
Message-Id: <E1HjOBs-0001Jh-Eg@wiggum.w3.org>

http://www.w3.org/Bugs/Public/show_bug.cgi?id=4523

           Summary: Default Unprefixed Namespace Handling is Problematic
           Product: XPath / XQuery / XSLT
           Version: Recommendation
          Platform: PC
        OS/Version: Windows XP
            Status: NEW
          Severity: normal
          Priority: P2
         Component: XQuery
        AssignedTo: chamberl@almaden.ibm.com
        ReportedBy: Kenneth.B.Sall@saic.com
         QAContact: public-qt-comments@w3.org
                CC: mike@saxonica.com


[This may be related to Bug ID 4463.]

There appears to be a namespace usability problem in XQuery 1.0: when the
source document is in no namespace and you need the result elements to be in a
default (unprefixed) namespace. My use case is KML, the markup for Google Earth
[see http://code.google.com/apis/kml/documentation/kml_tut.html ]

Iíve having difficulty outputting the correct default namespace from a query.
[I'm using SaxonB 8.9J on Windows XP with jre 1.6.0_01.]

With this trivial input:

<?xml version="1.0" encoding="UTF-8"?>
<bar>foobar</bar>

and trivial XQuery #1:

<kml>
  <Folder>
        {
        for $i in doc("namespace.xml")//bar
        return $i
        }
  </Folder>
</kml>

I get the result #1:

<?xml version="1.0" encoding="UTF-8"?>
<kml>
   <Folder>
      <bar>foobar</bar>
   </Folder>
</kml>

However, I need the opening <kml> to appear as:

<kml xmlns="http://earth.google.com/kml/2.1">

With XQuery #2:

<kml xmlns="http://earth.google.com/kml/2.1">
  <Folder>
        {
        for $i in doc("namespace.xml")//bar
        return $i
        }
  </Folder>
</kml>

I get result #2:

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.1">
   <Folder/>
</kml>

Which isn't correct for the <Folder> content.

I've also tried adding a default namespace declaration to XQuery #2:

declare default element namespace "http://earth.google.com/kml/2.1";

but that has no impact; I still get result #2.

Unfortunately, Google Earth really seems to expect an unprefixed default
namespace. When I take their basic examples and add a prefix, like so:

<?xml version="1.0" encoding="UTF-8"?>
<ge:kml xmlns:ge="http://earth.google.com/kml/2.1">
   <ge:Folder>
      <ge:Placemark>
         <ge:name>Simple placemark</ge:name>
         <ge:description>Attached to the ground. Intelligently places itself 
       at the height of the underlying terrain.
                </ge:description>
         <ge:Point>
                       
<ge:coordinates>-122.0822035425683,37.42228990140251,0</ge:coordinates>
         </ge:Point>
      </ge:Placemark>
   </ge:Folder>
</ge:kml>

Google Earth thinks the root <kml> element is "bad or missing". Therefore, my
use case is problematic with XQuery 1.0, as far as I understand.

The workaround is to simply output "<kml>" with no namespace attribute, which
Google Earth appears to understand, although the usability issue remains for
XQuery.
Received on Wednesday, 2 May 2007 23:25:04 UTC

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