Passing an XmlElement to a background job in powershell - powershell

Question

I've read that objects are serialized when you pass them into a script block called with start-job. This seems to work fine for strings and things, but I'm trying to pass an xml.XmlElement object in. I'm sure that the object is an XMLElement before I invoke the script block, but in the job, I get this error:
Cannot process argument transformation on parameter 'node'. Cannot convert the "[xml.XmlElement]System.Xml.XmlElement"
value of type "System.String" to type "System.Xml.XmlElement".
+ CategoryInfo : InvalidData: (:) [], ParameterBindin...mationException
+ FullyQualifiedErrorId : ParameterArgumentTransformationError
+ PSComputerName : localhost
So, how do I get my XmlElement back. Any ideas?
For what it's worth, this is my code:
$job = start-job -Name $node.LocalName -InitializationScript $DEFS -ScriptBlock {
param (
[xml.XmlElement]$node,
[string]$folder,
[string]$server,
[string]$user,
[string]$pass
)
sleep -s $node.startTime
run-action $node $folder $server $user $pass
} -ArgumentList $node, $folder, $server, $user, $pass

Answer 1

Apparently you can't pass XML nodes into script blocks because you can't serialize them. According to this answer you need to wrap the node into a new XML document object and pass that into the script block. Thus something like this might work:
$wrapper = New-Object System.Xml.XmlDocument
$wrapper.AppendChild($wrapper.ImportNode($node, $true)) | Out-Null
$job = Start-Job -Name $node.LocalName -InitializationScript $DEFS -ScriptBlock {
param (
[xml]$xml,
[string]$folder,
[string]$server,
[string]$user,
[string]$pass
)
$node = $xml.SelectSingleNode('/*')
sleep -s $node.startTime
run-action $node $folder $server $user $pass
} -ArgumentList $wrapper, $folder, $server, $user, $pass