Powershell updating value of array objects in XML file

Question

I have previously asked this question on the Spiceworks community, but have not received any responses yet. If you guys don't mind i would like to try my luck here. So here goes:

I am working with editing XML files with Powershell. Most of my edits work perfectly fine, except the portion I am updating with whatever comes back from the regex results.

Here is the sample XML section:

<?xml version="1.0" encoding="utf-8"?>
<assetPackages xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; xmlns:xsd="http://www.w3.org/2001/XMLSchema"; verb="">
    <assetPackage asset_name="JackalCLSDMP0802title" type="VOD" providerID="starzencore.com" providerName="MOVIEPLEX" creationDate="2013-07-11" product="MOD" version="1" verb="">
        <metadata>
            <assetID>TITL0020000000864577</assetID>
            <providerID>starzencore.com</providerID>
            <title language="en">The Jackal</title>
            <sortTitle language="en">The Jackal</sortTitle>
        <reducedTitle language="en">The Jackal</reducedTitle>
            <summary language="en">Summary is Long</summary>
            <shortSummary language="en">Shorter Summary</shortSummary>
            <flag>ClosedCaptioning</flag>
            <rating rating_system="MPAA" value="R" />
            <runTimeMinutes>125</runTimeMinutes>
            <release_year>1997</release_year>
            <countryRegionCode>us</countryRegionCode>
            <person role="director" lname="Caton-Jones" fname="Michael" mname="" />
            <person role="actor" lname="Willis" fname="Bruce" mname="" />
            <person role="actor" lname="Gere" fname="Richard" mname="" />
            <studio>UNIVERSAL PAY TELEVISION</studio>
            <category>Premium Channels/Movieplex/All Movies</category>
            <category>Premium Channels/Movieplex/Drama</category>
            <category>Premium Channels/Movieplex/Top Hits</category>
            <targetingProfileId>MoviePlex_VOD</targetingProfileId>
        </metadata>
    </assetPackage>
</assetPackages>

And here is my current snippet of code:

$TempXML = @(Get-ChildItem $tempDir -recurse -filter "Metadata.xml" | Where-Object {$_.FullName -like "*$($like)*"})

    $Results = @()

    ### Edit XML Process
    ForEach ($File in $tempXML)
    {
        $xmlData = [xml](Get-Content "\\Wtcvhovmgmt001\Staging\starzencore.com-TITL0020000000864577\metadata.xml") #(Get-Content $File.Fullname)
        $xmli = $xmlData.assetpackages.assetpackage

        #Regex to replace string in metadata category
        ForEach ($c in ($xmli.metadata.category))
        {
            if ({ $c -notlike "*Subscriptions*" })
            {
                $regex = "^[^/]*(.*)$"
                $c -match $regex
                $c = "Subscriptions" + $matches[1]
                #$c
            }
        }
        $xmlData.Save("\\Wtcvhovmgmt001\Staging\starzencore.com-TITL0020000000864577\metadata.xml") #$xmlData.Save($File.Fullname)

        $DirName = Split-Path (Split-Path $file.Fullname -Parent) -Leaf
        $Results += New-Object PSObject -Property @{
            "Date/Time" = $Date
            File = $($file.FullName)
            "Last Write Time" = $($file.LastWriteTime)
            Directory = $($DirName)
            Status = "Successful"
            }
        Write-Host "Succesfully processed $($File.Fullname)" -foregroundcolor green -backgroundcolor black

        #Write event to event log for successful metadata editing
        #Write-Eventlog -ComputerName "WTCVHOVCTRL001" Application -source "Microsoft IPTV" -eventid 14888 -message "Successfully edited/updated $($File.Fullname). File is ready for reimport"
    }

The problem I am running into is that when I am inside the ForEach loop attempting to change the value of each item in the Array to the results of the Regex command. It appears to create a variable $c, populate it with the correct value, but then never write that value to the current item in the array that the ForEach is processing.

I have also tried something like the below code (that produced errors):

#Regex to replace string in metadata category
$xmli.metadata.category | ForEach-Object
{
    $regex = "^[^/]*(.*)$"
    $_ -match $regex
    $_ = "Subscriptions" + $matches[1]
}

Any ideas why it's not updating the value of each category node?

Answer 1

Instead of this:

 $xmli = $xmlData.assetpackages.assetpackage

 #Regex to replace string in metadata category
 ForEach ($c in ($xmli.metadata.category))
 {
     if ({ $c -notlike "*Subscriptions*" })
     {
         $regex = "^[^/]*(.*)$"
         $c -match $regex
         $c = "Subscriptions" + $matches[1]
         #$c
     }
 }

try this:

$xmli.SelectNodes('//category[not(starts-with(.,"Subscriptions"))]') | % {
  $_.'#text' = $_.'#text' -replace '^[^/]*(.*)$', 'Subscriptions$1'
}