Remove an XML node using PowerShell

Question

I'm trying to remove <Element>SlowPollGroup</Element> from the XML below. <Markers> is four levels deep in the XML file. I've already found <Markers> as $markersExists using $markersExists = $vendor.SelectSingleNode("./Markers") script.

  <Markers>
    <Element>Group2</Element>
    <Element>Group3</Element>
    <Element>Group4</Element>
    <Element>HWSimSubscription</Element>
    <Element>DIO_TC</Element>
    <Element>CmdSubGroup</Element>
    <Element>FastPollGroup</Element>
    <Element>SlowPollGroup</Element>
    <Element>HWSimPoll</Element>
    <Element>WriteOnly</Element>
  </Markers>

I've tried the script below:

        $groupNameSPG = "SlowPollGroup"
        $delMarkerElem = $groupNameSPG

        LogWrite ("Searching for Markers")
        $markersExists = $vendor.SelectSingleNode("./Markers")
        if ($null -ne $markersExists) {
            LogWrite ("Markers found")

            foreach($element in $markersExists.Element) {
                if ( $element -eq $delMarkerElem) {
                    LogWrite ($delMarkerElem + " found")
                    $delElem = $element.ParentNode
                    $delMarkerElemFound = $true
                    break
                }
                LogWrite ("Searching for [$delMarkerElem] again")
            }

            if ($delMarkerElemFound) {
                $markersExists.RemoveChild($element) | Out-Null
                LogWrite ("Removed => [$delMarkerElem]")
            }
            else {
                LogWrite ("delMarkerElemFound => [$delMarkerElemFound]")
            }
        }

Log file excerpt looks like below:

Searching for Markers
Markers found
Searching for [SlowPollGroup] again
Searching for [SlowPollGroup] again
Searching for [SlowPollGroup] again
Searching for [SlowPollGroup] again
Searching for [SlowPollGroup] again
Searching for [SlowPollGroup] again
Searching for [SlowPollGroup] again
SlowPollGroup found
Removed => [SlowPollGroup]

However, when I tested the whole script in Windows PowerShell ISE on Win10, the output looks like below:

PowerShell Error v01

I've used the code below:

        $groupsExists = $vendor.SelectSingleNode("./Groups")
        if ($null -ne $groupsExists) {
            LogWrite ("Groups found")
            foreach($element in $groupsExists.Element) {
                if ( $element.Name -eq $groupElemName) {
                    LogWrite ($groupElemName + " found")
                    $groupElemNameFound = $true
                    break
                }
                LogWrite ("Searching for " + $groupElemName + " again")
            }

            if ($groupElemNameFound) {
                $groupsExists.RemoveChild($element) | Out-Null
                LogWrite ("Removed => $groupElemName")
            }
        }

on the XML below

  <Groups>
    <Element>
      <Name>Group1</Name>
      <PollInterval>200</PollInterval>
      <UseDataSubscription>True</UseDataSubscription>
    </Element>
    <Element>
      <Name>AlarmGroup</Name>
      <PollInterval>1000</PollInterval>
    </Element>
    <Element>
      <Name>GVL_TC</Name>
      <PollInterval>100</PollInterval>
    </Element>
  </Groups>

to remove the last Element, ie

    <Element>
      <Name>GVL_TC</Name>
      <PollInterval>100</PollInterval>
    </Element>

and it worked. I understand both XML structures are different and I suspect $element in the top script contains only 'SlowPollGroup', not <Element>SlowPollGroup</Element> . I've been at this over the weekend trying out various scripts offered from Google searches, but no dice. Any help is greatly appreciated.

Answer 1

Apparently, this script works as I want it to:

        LogWrite ("Searching for Markers")
        $markersExists = $vendor.SelectSingleNode("./Markers")
        if ($null -ne $markersExists) {
            LogWrite ("Markers found")

            # $delMarkerElem needs to be within ''
            $node = $markersExists.SelectSingleNode("./Element[.='$delMarkerElem']")

            if ($null -ne $node) {
                $node.ParentNode.RemoveChild($node)
                LogWrite ("Removed => Element node=[$node] with delMarkerElem=[$delMarkerElem]")
            }
            else {
                LogWrite ("Not found - Element node=[$node] with delMarkerElem=[$delMarkerElem]")
            }
        }

Modified from this script:

$node = $conns.SelectSingleNode("//Description[.='HP Command View EVA']")
while ($node -ne $null) {
    $node.ParentNode.RemoveChild($node)
    $node = $conns.SelectSingleNode("//Description[.='HP Command View EVA']")
}

found from http://jon.netdork.net/2013/01/09/removing-xml-elements-using-powershell/