Parsing XML and ignoring sections with powershell - powershell

Question

I want to parse out the key fields and Data table information from here with PowerShell.
I only want the datatable name if there is a keyfield so in the example below I do not want CC:Attribute.
I also want to output things to a text file.
I want to have a text file that is created that holds the Data table name & Access as well as all the key fields and what they are.
This is the code I have so far:
[xml]$global:xmldata = get-content "C:\hackathon\Mfg.xml"
$xmldata2 = $xmldata.SchemaPackage.Tables
$SField = $xmldata2.DataTable.KeyFields | %{$_.StringField}
$Reffield = $xmldata2.DataTable.KeyFields | %{$_.ReferenceField}
$table = $xmldata2 | %{$_.DataTable}
Xml File:
<?xml version="1.0" encoding="utf-8"?>
<SchemaPackage Namespace="Mfg" xmlns="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<DataTable Name="CC::Attribute">
<DataFields>
</DataFields>
</DataTable>
<DataTable Name="PlannerCode" Access="WW">
<Licenses>Manufacturing, DemandManagement</Licenses>
<Flags>
</Flags>
<KeyFields>
<StringField Name="Value"/>
<ReferenceField Name="Site" Target="Core::Site" SetField="PlannerCodes"/>
</KeyFields>
<DataFields>
<StringField Name="Description"/>
</DataFields>
</DataTable>
</SchemaPackage>

Answer 1

Despite the edit you made, I can only get your XML to validate if I modify it slightly (cleaning the opening XML tag and removing the SchemaPackage namespace). Regardless,
if you're experiencing no issues with your XML import then it's fine.
Here I'm just constructing the XML object from a herestring because I haven't got it in a file on disk.
[xml]$xmldata = #"
<xml>
<DataTable Name="CC::Attribute">
<DataFields>
</DataFields>
</DataTable>
<DataTable Name="PlannerCode">
<Licenses>Manufacturing, DemandManagement</Licenses>
<Flags>
</Flags>
<KeyFields>
<StringField Name="Value"/>
<ReferenceField Name="Site" Target="Core::Site" SetField="PlannerCodes"/>
</KeyFields>
<DataFields>
<StringField Name="Description"/>
</DataFields>
</DataTable>
</xml>
"#
# Filter DataTable nodes for those with a KeyFields child node.
$DataTablesWithKeyFields = $xmldata.xml.DataTable | Where-Object { $_.KeyFields }
$DataTableName = $DataTablesWithKeyFields.Name
$StringFieldData = $DataTablesWithKeyFields.KeyFields.ReferenceField
$ReferenceFieldData = $DataTablesWithKeyFields.KeyFields.ReferenceField
I'm not sure if that's what you're after. $DataTablesWithKeyFields could be an array depending on your XML file so you may need to loop it to extract the information you require.

Answer 2

Since we're working with XML, one of the querying options is XPath!
You can select only DataTable nodes that have a KeyFields child with the following XPath expression:
/SchemaPackage/DataTable[KeyFields]
You can use Select-Xml:
Select-Xml -Path C:\hackathon\Mfg.xml -XPath /SchemaPackage/DataTable[KeyFields] |Select-Object -Expand Node
or pass the expression as an argument to the SelectSingleNodes() method:
[xml]$xmldata = Get-Content C:\hackathon\Mfg.xml
$xmldata.SelectNodes('/SchemaPackage/DataTable[KeyFields]')