SelectNodes in XPathNodeList - powershell

Question

Given an XPathNodeList derived with something like this
$settingsNodes = $temp.xml.SelectNodes('/Settings/*')
And given a particular node Name or ID, I can iterate the XPathNodeList, test for a match and increment a counter. However, I wonder if there is something more elegant, along the lines of
$count = $settingsNodes.SelectNodes("//$nodeName")
That doesn't work because an XPathNodeList doesn't have a SelectNodes method, and I can't seem to find anything that does work. Googling XPathNodeList SelectNodes returns all sorts of references to SelectNodes as a method of XmlNode, but nothing on XPathNodeList.
My specific condition means I am almost certainly never looping through more than a few hundred to perhaps a thousand nodes, so maybe it really doesn't matter, it just seems like there is probably or more graceful solution and I just haven't found it.
EDIT: For additional context.
In one condition I might have this XML and I just want to catch and log the duplicate UserLogFilePath node.
<Settings>
<JobsXML>[Px~Folder]\Resources\jobs.xml</JobsXML>
<JobLogFilePath>[Px~Folder]\Logs</JobLogFilePath>
<JobLogFileName>[Px~StartTime] Job [Px~Job][Px~Error]</JobLogFileName>
<MachineLogFilePath>[Px~Folder]\Logs</MachineLogFilePath>
<MachineLogFileName>[Px~Now] [Px~Action] [Px~Set] on [Px~Computer][Px~Error][Px~Validation]</MachineLogFileName>
<ResetLogFilePath>[Px~Folder]\Logs</ResetLogFilePath>
<ResetLogFileName>[Px~Now] [Px~Action] on [Px~Computer][Px~Error][Px~Validation]</ResetLogFileName>
<UserLogFilePath>[Px~Folder]\Logs</UserLogFilePath>
<UserLogFilePath>C:\Program Files</UserLogFilePath>
<UserLogFileName>[Px~User] on [Px~Computer]</UserLogFileName>
<UserContextMember></UserContextMember>
<UserContextNotMember>Administrators</UserContextNotMember>
</Settings>
If there are no duplicates the entire Settings node is imported into my XML variable in memory.
Later, I might have this XML and I want to catch duplicate IDs, both in and outside of any Product_Group.
<Definitions>
<Products>
<Product_Group id="Miscellaneous">
<Product id="ADSK360">
<DefaultShortcut>Autodesk 360.lnk</DefaultShortcut>
<ProgramDataFolder>C:\ProgramData\Autodesk\Autodesk ReCap</ProgramDataFolder>
<ProgramFolder>C:\Program Files\Autodesk\Autodesk Sync</ProgramFolder>
<ShortcutPath>C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Autodesk</ShortcutPath>
</Product>
<Product id="ADSK360">
<DefaultShortcut>Autodesk 360.lnk</DefaultShortcut>
<ProgramDataFolder>C:\ProgramData\Autodesk\Autodesk ReCap</ProgramDataFolder>
<ProgramFolder>C:\Program Files\Autodesk\Autodesk Sync</ProgramFolder>
<ShortcutPath>C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Autodesk</ShortcutPath>
</Product>
</Product_Group>
<Product id="ADSK360">
<DefaultShortcut>Autodesk 360.lnk</DefaultShortcut>
<ProgramDataFolder>C:\ProgramData\Autodesk\Autodesk ReCap</ProgramDataFolder>
<ProgramFolder>C:\Program Files\Autodesk\Autodesk Sync</ProgramFolder>
<ShortcutPath>C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Autodesk</ShortcutPath>
</Product>
</Products>
</Definitions>
If there are no duplicates the Product_Groups are eliminated (it's just a convenience for users managing their XML) and all the Products are imported into the Products node in memory.
Subsequent product files are checked first for internal duplicates, and if none are found checked for duplicates already in the main XML, and if none found the file's XML is merged. This repeats for potentially a hundred or more total files in some cases.
The current loop based approach is inelegant, especially for the internal duplicates test. I make an XPathNodesList, say of all the Products, in the candidate XML. This is where SelectNodes is nice because it can find Products in a Product_Group or not. Then I loop through each product and test it against the whole XPathNodesList. Ugly because a list of only 10 nodes means 100 times through the loop. When testing the candidate against the final XML it's more efficient, but still ugly.
EDIT #2:
Taking a stab at using Select, I have this correctly finding duplicate nodes.
$settingsNodes = $temp.xml.SelectNodes('/Settings/*')
Write-Host "$($settingsNodes.count)"
Write-Host "$(($settingsNodes | select -unique).count)"
But how does one find only duplicate IDs? Better yet duplicate IDs with the same node name? Since a different node name but the same ID would actually not be a duplicate. -unique is a bool I see, so my guess is I am about to learn something more about pipelining, because I need to extract the IDs to pipe to Select -unique, which isn't Where-Object. How does one just pull the IDs in this case?
OK, gut test here. I think maybe I am trying to be a bit too clever when in fact there is a much easier solution. To wit...
$settingsNodes = $temp.xml.SelectNodes('/Settings/*')
$unique = $duplicate = #()
foreach ($node in $settingsNodes) {
if ($unique -contains $node.Name) {
$duplicate += $node.Name
} else {
$unique += $node.Name
}
}
Write-Host "u: $unique"
Write-Host " "
Write-Host "d: $duplicate"
Swap Name for ID and it works for that too. The SelectNodes will take care of eliminating the Product_Group. And similarly I can build an array of the nodes in Final to test against with the now unique list of candidate nodes.
So, am I missing something that is going to bite me? Or should I just go ahead and kick myself? ;)