I am terribly confused about how I am supposed to make XML::LibXML correctly use name spaces.

I am experimenting with CalDAV and I include two examples from RFC4918 

# Example in section 9.1.3 of RFC4918
my $txt1 = '<?xml version="1.0" encoding="utf-8" ?>
     <D:propfind xmlns:D="DAV:">
       <D:prop xmlns:R="http://ns.example.com/boxschema/">
         <R:bigbox/>
         <R:author/>
         <R:DingALing/>
         <R:Random/>
       </D:prop>
     </D:propfind>
';

# Example in section 9.1.5 of RFC4918
my $txt2 = '<?xml version="1.0" encoding="utf-8" ?>
     <propfind xmlns="DAV:">
       <propname/>
     </propfind>
';

[download]

The first example uses 'D' as a prefix for 'DAV' (xmlns:D="DAV:") and the second uses "DAV" as the default name space.

The RFC says of the second example... "[$txt2] demonstrates the use of XML namespace scoping and the default namespace. Since the "xmlns" attribute does not contain a prefix, the namespace applies by default to all enclosed elements.".

The code I am using is: 

#!/usr/bin/perl -w
use strict;
use XML::LibXML;

sub doitLX {
    my $contentRef = shift or die;
    my $content = $$contentRef;
    my $xpath = shift or die;

    $|++;


    my $parser = XML::LibXML->new();
    my $dom = $parser->parse_string($content);
    my $doc = $dom->documentElement();
    my @propfind = ();
    eval {
    @propfind = $dom->findnodes($xpath);
    };
    if($@){
    print "Failed ".ref($dom)."::findnodes('$xpath') \$@ $@\n";
    }else{

    print ref($dom)."::findnodes('$xpath') ".scalar(@propfind)." nodes
+\n\n";
    }
    eval {
    @propfind = $doc->findnodes($xpath);
    };
    if($@){
    print "Failed ".ref($doc)."::findnodes('$xpath') \$@ $@\n";
    }else{

    print ref($doc)."::findnodes('$xpath') ".scalar(@propfind)." nodes
+\n\n";
    }
    
}


# Example in section 9.1.3 of RFC4918
my $txt1 = '<?xml version="1.0" encoding="utf-8" ?>
     <D:propfind xmlns:D="DAV:">
       <D:prop xmlns:R="http://ns.example.com/boxschema/">
         <R:bigbox/>
         <R:author/>
         <R:DingALing/>
         <R:Random/>
       </D:prop>
     </D:propfind>
';

# Example in section 9.1.5 of RFC4918
my $txt2 = '<?xml version="1.0" encoding="utf-8" ?>
     <propfind xmlns="DAV:">
       <propname/>
     </propfind>
';

my $xpath1 = '/DAV:propfind/DAV:prop';
my $xpath2 = '/DAV:propfind/DAV:propname';
my $xpath3 = '/D:propfind/D:prop';
my $xpath4 = '/D:propfind/D:propname';
my $xpath5 = '/propfind/prop';
my $xpath6 = '/propfind/propname';

print "\$txt1 \$xpath1 \n";
&doitLX(\$txt1, $xpath1);
print "\$txt2 \$xpath2 \n";
&doitLX(\$txt2, $xpath2);
print "\$txt1 \$xpath3 \n";
&doitLX(\$txt1, $xpath3);
print "\$txt2 \$xpath4 \n";
&doitLX(\$txt2, $xpath4);
print "\$txt1 \$xpath5 \n";
&doitLX(\$txt1, $xpath5);
print "\$txt2 \$xpath6 \n";
&doitLX(\$txt2, $xpath6);

[download]

The output is: 

$txt1 $xpath1 
Failed XML::LibXML::Document::findnodes('/DAV:propfind/DAV:prop') $@ X
+Path error : Undefined namespace prefix
 error : xmlXPathCompiledEval: evaluation failed

Failed XML::LibXML::Element::findnodes('/DAV:propfind/DAV:prop') $@ XP
+ath error : Undefined namespace prefix
 error : xmlXPathCompiledEval: evaluation failed

$txt2 $xpath2 
Failed XML::LibXML::Document::findnodes('/DAV:propfind/DAV:propname') 
+$@ XPath error : Undefined namespace prefix
 error : xmlXPathCompiledEval: evaluation failed

Failed XML::LibXML::Element::findnodes('/DAV:propfind/DAV:propname') $
+@ XPath error : Undefined namespace prefix
 error : xmlXPathCompiledEval: evaluation failed

$txt1 $xpath3 
XML::LibXML::Document::findnodes('/D:propfind/D:prop') 1 nodes

XML::LibXML::Element::findnodes('/D:propfind/D:prop') 1 nodes

$txt2 $xpath4 
Failed XML::LibXML::Document::findnodes('/D:propfind/D:propname') $@ X
+Path error : Undefined namespace prefix
 error : xmlXPathCompiledEval: evaluation failed

Failed XML::LibXML::Element::findnodes('/D:propfind/D:propname') $@ XP
+ath error : Undefined namespace prefix
 error : xmlXPathCompiledEval: evaluation failed

$txt1 $xpath5 
XML::LibXML::Document::findnodes('/propfind/prop') 0 nodes

XML::LibXML::Element::findnodes('/propfind/prop') 0 nodes

$txt2 $xpath6 
XML::LibXML::Document::findnodes('/propfind/propname') 0 nodes

XML::LibXML::Element::findnodes('/propfind/propname') 0 nodes

[download]

As far as I can tell the XPats: 

my $xpath1 = '/DAV:propfind/DAV:prop';
my $xpath2 = '/DAV:propfind/DAV:propname';

[download]

are the correct ones. But I cannot find any documentation that addresses default name spaces. I am lost...

Worik

In reply to xmlns and XML::LibXML by Anonymous Monk

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