How do I access an element with xpath with a namespace in powershell?

Question

Powershell:

$doc = new-object System.Xml.XmlDocument
$doc.Load($filename)

$items = Select-Xml -Xml $doc -XPath '//item'
$items | foreach {
    $item = $_
    write-host $item.name
}

I get no output

XML:

<?xml version="1.0" encoding="UTF-8"?>
<submission version="2.0" type="TREE" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:noNamespaceSchemaLocation="TREE.xsd" xmlns="some/kind/of/tree/v1">
  <group>
    <item></item>
    <item></item>
    <item></item>
  </group>
<submission>

Answer 1

You've got a few problems going on. First you need to specify the namespace in the XPath pattern, the XML isn't well formed (closing tag is not an end tag) and Select-Xml returns XmlInfo and not XmlElement directly. Try this:

$xml = [xml]@'
<submission version="2.0" type="TREE" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:noNamespaceSchemaLocation="TREE.xsd" xmlns="some/kind/of/tree/v1">
  <group>
    <item></item>
    <item></item>
    <item></item>
  </group>
</submission>
'@

$ns = @{dns="some/kind/of/tree/v1"}
$items = Select-Xml -Xml $xml -XPath '//dns:item' -Namespace $ns
$items | Foreach {$_.Node.Name}