Quick and Easy PowerShell Test-XMLFile

The PowerShell community extensions module contains Test-XML which can perform a number of checks for the validity of an XML file. For my particular needs I wasn’t able to take a dependency on an external module, consequently I needed to make something similar of my own to carry out some basic tests.

The below function makes use of the XmlException exception from the XmlDocument class . An attempt is made to load the XML file and then any Load or Parse errors are caught by the XmlException exception.

Let’s take a look at a couple of examples:

The following XML file is missing a closing ‘/’ in Set 1 for Orange

<Data>
<Set1>
<Name>Orange</Name>
<Colour>Orange</Colour>
<Set1>

<Set1>
<Name>Apple</Name>
<Colour>Green</Colour>
</Set1>
</Data>

The function will pick it up like this:

Test-XMLFile Fruit.xml -verbose

Note that it also returns $true or $false so you can use it say in ‘if’ statements.

In this example an additional </Set1> has been erroneously copied into the wrong place.

<Data>
<Set1>
<Name>Orange</Name>
<Colour>Orange</Colour>
</Set1>

</Set1>
<Set1>
<Name>Apple</Name>
<Colour>Green</Colour>
</Set1>
</Data>

The function will pick it up like this:

Test-XMLFile Fruit.xml -verbose

function Test-XMLFile {
<#
.SYNOPSIS
Test the validity of an XML file
#>
[CmdletBinding()]
param (
[parameter(mandatory=$true)][ValidateNotNullorEmpty()][string]$xmlFilePath
)

# Check the file exists
if (!(Test-Path -Path $xmlFilePath)){
throw "$xmlFilePath is not valid. Please provide a valid path to the .xml fileh"
}
# Check for Load or Parse errors when loading the XML file
$xml = New-Object System.Xml.XmlDocument
try {
$xml.Load((Get-ChildItem -Path $xmlFilePath).FullName)
return $true
}
catch [System.Xml.XmlException] {
Write-Verbose "$xmlFilePath : $($_.toString())"
return $false
}
}