How to fetch an attribute value from xml using powershell?

Question

I have a list of XML files, from which I have to get the string after a particular line.

In the files, I need to look for a tag Event and get the attribute value DLLRoutine. e.g. the tag would look something like below ...

<Event Definition="Validate" DLLPath="" DLLName="Helper.dll" DLLClass="HelpMain" 
       DLLRoutine="pgFeatureInfoOnValidate_WriteToRegSelectedFeatures" 
       InputParameters="pTreeViewFeatureTreeServerOS" RunOnce="no"/>

I just need to get Dllroutine values. How to do it using PowerShell?

Answer 1

Assuming your XML structure is something similar to:

$xml = [xml]'
<Events>
<Event Definition="Validate" DLLPath="" DLLName="Helper.dll" DLLClass="HelpMain" DLLRoutine="pgFeatureInfoOnValidate_WriteToRegSelectedFeatures" InputParameters="pTreeViewFeatureTreeServerOS" RunOnce="no"/>
<Event Definition="Validate1" DLLPath="" DLLName="Helper.dll1" DLLClass="HelpMain1" DLLRoutine="pgFeatureInfoOnValidate_WriteToRegSelectedFeatures" InputParameters="pTreeViewFeatureTreeServerOS" RunOnce="no"/>
</Events>
'

#Or get it from a XML file
$xml = [xml](Get-Content $XMLPath)

$xml.Events.Event | Select DLLName

Answer 2

Assuming your Event element has an Events element root:

$xml.Events.Event.DLLName

I've only tested this in Powershell 3

Answer 3

you can use also xpath instead of dot notation:

$xml.SelectNodes('//Events/Event') | select DLLName

Answer 4

Try $xml.Events.Event.DLLName

It will work in version 2, I have tried to use xpath in several scripts and it fails every time so until I tried the dot notation I thought I was doing it wrong.

Answer 5

You could use Select-XML:

$xml = [xml]'
<Events>
<Event Definition="Validate" DLLPath="" DLLName="Helper.dll" DLLClass="HelpMain" DLLRoutine="pgFeatureInfoOnValidate_WriteToRegSelectedFeatures" InputParameters="pTreeViewFeatureTreeServerOS" RunOnce="no"/>
<Event Definition="Validate1" DLLPath="" DLLName="Helper.dll1" DLLClass="HelpMain1" DLLRoutine="pgFeatureInfoOnValidate_WriteToRegSelectedFeatures" InputParameters="pTreeViewFeatureTreeServerOS" RunOnce="no"/>
</Events>
'

Select-XML -xml $xml -xpath "//Event/@DLLName"