How do I use PowerShell to Validate XML files against an XSD?

Question

As a part of my development I\'d like to be able to validate an entire folder\'s worth of XML files against a single XSD file. A PowerShell function seems like a good candid

Answer 1

The PowerShell Community Extensions has a Test-Xml cmdlet. The only downside is the extensions havn't been updated for awhile, but most do work on the lastest version of powershell (including Test-Xml). Just do a Get-Childitem's and pass the list to a foreach, calling Test-Xml on each.

Answer 2

I re-wrote it (I know bad habbit) , but the starting script by @Flatliner_DOA was too good to discard completely.

function Test-Xml {
[cmdletbinding()]
param(
    [parameter(mandatory=$true)]$InputFile,
    $Namespace = $null,
    [parameter(mandatory=$true)]$SchemaFile
)

BEGIN {
    $failCount = 0
    $failureMessages = ""
    $fileName = ""
}

PROCESS {
    if ($inputfile)
    {
        write-verbose "input file: $inputfile"
        write-verbose "schemafile: $SchemaFile"
        $fileName = (resolve-path $inputfile).path
        if (-not (test-path $SchemaFile)) {throw "schemafile not found $schemafile"}
        $readerSettings = New-Object -TypeName System.Xml.XmlReaderSettings
        $readerSettings.ValidationType = [System.Xml.ValidationType]::Schema
        $readerSettings.ValidationFlags = [System.Xml.Schema.XmlSchemaValidationFlags]::ProcessIdentityConstraints -bor
            [System.Xml.Schema.XmlSchemaValidationFlags]::ProcessSchemaLocation -bor 
            [System.Xml.Schema.XmlSchemaValidationFlags]::ReportValidationWarnings
        $readerSettings.Schemas.Add($Namespace, $SchemaFile) | Out-Null
        $readerSettings.add_ValidationEventHandler(
        {
            try {
                $detail = $_.Message 
                $detail += "`n" + "On Line: $($_.exception.linenumber) Offset: $($_.exception.lineposition)"
            } catch {}
            $failureMessages += $detail
            $failCount = $failCount + 1
        });
        try {
            $reader = [System.Xml.XmlReader]::Create($fileName, $readerSettings)
            while ($reader.Read()) { }
        }
        #handler to ensure we always close the reader sicne it locks files
        finally {
            $reader.Close()
        }
    } else {
        throw 'no input file'
    }
}

END {
    if ($failureMessages)
    { $failureMessages}
    write-verbose "$failCount validation errors were found"

}
}

#example calling/useage  code follows:
$erroractionpreference = 'stop'
Set-strictmode -version 2

$valid = @(Test-Xml -inputfile $inputfile -schemafile $XSDPath )
write-host "Found ($($valid.count)) errors"
if ($valid.count) {
    $valid |write-host -foregroundcolor red
}

The function no longer pipelines as an alternative to using a file-path, it's a complication this use-case does not need. Feel free to hack the begin/process/end handlers away.