From: matt_neuburg@... (Matt Neuburg)
Date: 2009-08-03T13:25:04+09:00
Subject: Re: : Can't find nodes using XPath, namespaces mess

Aaron Patterson <aaron@tenderlovemaking.com> wrote:

> You have an error in your XML below

Thanks for spotting that. I must have removed the namespace and then put
it back, to see if I could duplicate the OP's problems, and I must have
put it back wrong. I wish libxml had just complained that my XML was
bad...

You're right; fixing the error, I can now duplicate the OP's problem in
libxml (but not in REXML, as you also observed). And then I can solve
it:

s = <<END
<?xml version="1.0" encoding="UTF-8"?>
<configuration-data
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:company:platform:foundation:configuration:defn:v
1"
xmlns="urn:company:platform:foundation:configuration:defn:v1">
<attributeList>
<attribute name="siteid" validationRuleName="String" description="Site
id">
<tree name="siteid_hierarchy">
<treenode name="Root">
<treenode name="1" />
</treenode>
</tree>
</attribute>
</attributeList>
</configuration-data>
END
require 'rubygems'
require 'xml'
doc = XML::Document.string(s)
ns = {"xsi" => "urn:company:platform:foundation:configuration:defn:v1"}
doc.find("//xsi:treenode['Root']/xsi:treenode", ns).each do |el|
  p el #=> <treenode name="1"/>
end

That is the desired sort of result, I take it. Notice that we register
the namespace with the XPath engine and that we actually use the
namescape in our XPath expression. m.