Powershell: Some basic XML handling with Powershell and .NET

Hi everybody,

here are some fundamentals to handle XML Files with powershell.

The following commands uses these XML File


<config description="Config file for testing">
    <system description="Document Management">
        <document authorFirstName="Kirk" authorSurname="Author1" date="20130503 01:15:43" description="Document Hammet" index="3">C:\temp\doc0001.txt</document>
        <document authorFirstName="Lars" authorSurname="Author5" date="20130503 10:05:42" description="Document Ulrich" index="4">C:\temp\doc0002.txt</document>
        <document authorFirstName="Cliff" authorSurname="Author5" date="20130612 11:54:33" description="Document Burton"  index="6">C:\temp\doc0051.txt</document>
        <document authorFirstName="Jason" authorSurname="Author2" date="20130806 04:02:41" description="Document Newsted"  index="1">C:\temp\doc0041.txt</document>
        <document authorFirstName="Robert" authorSurname="Smith" date="20131202 07:12:03" description="Document Trujillo"  index="2">C:\temp\doc0012.txt</document>
        <document authorFirstName="James" authorSurname="Smith" date="20130211 09:05:59" description="Document Hetfield"  index="5">C:\temp\doc0003.txt</document>
    </system>
</config>

Creating  a XML File, create a document root, create subelements, add and set attributes, save the file

# Create a new XML File with config root node
[System.XML.XMLDocument]$oXMLDocument=New-Object System.XML.XMLDocument
# New Node
[System.XML.XMLElement]$oXMLRoot=$oXMLDocument.CreateElement("config")
# Append as child to an existing node
$oXMLDocument.appendChild($oXMLRoot)
# Add a Attribute
$oXMLRoot.SetAttribute("description","Config file for testing")
[System.XML.XMLElement]$oXMLSystem=$oXMLRoot.appendChild($oXMLDocument.CreateElement("system"))
$oXMLSystem.SetAttribute("description","Document Management")
# Save File
$oXMLDocument.Save("c:\temp\config.xml")

Loading an existing XML File, read an element, do some XPATH queries


# Loading a XML File
[[xml]]$oXMLDocument=Get-Content -Path "c:\temp\config.xml"
# or
$oXMLDocument=New-Object System.XML.XMLDocument
$oXMLDocument.Load("c:\temp\config.xml")
# Accessing a node/attribute
write-host $oXMLDocument.config.description
# Get all documents from Author "Smith"
$oDocsSmith=$oXMLDocument.selectNodes("config/system/document[@authorSurname=""Smith""]")
# Get all documents from Author "Smith" with date February 2013, XPATH Query relative to document root, http://msdn.microsoft.com/en-US/library/ms256086.aspx
$oDocsSmithFeb13=$oXMLDocument.selectNodes("config/system/document[@authorSurname=""Smith"" and starts-with(@date,""201302"")]")

Here are some examples
Get all Titles from a RSS Feed


[System.Net.WebClient]$oWebClient = New-Object System.Net.WebClient
# Get Proxy from Internet Explorer
oWebClient.proxy=[System.Net.WebProxy]::GetDefaultProxy()
$oRSSFeed=[[xml]]$oWebClient.DownloadString("http://michlstechblog.info/blog/feed/")
$oRSSFeed.rss.channel.item|foreach{write-host $_.title}

Copy a XML Node from one document to another

# Get XML Document Object from String
[[xml]]$oConfig2Merge='<config description="Users">
  <customers>
    <user surname="Campbell" firstname="Wayne">Wayne</user>
    <user surname="Garth" firstname="Algar">Garth</user>
    <user surname="Cheers" firstname="Phil">Phil</user>
  </customers>
</config>'
# Migrate the customers node to our config file defined at the top of the post
# Get the target config Node
$oXMLConfigTarget=$oXMLDocument.selectSingleNode("config")
# Get the Node which is to migrate
$oXMLCustomers=$oConfig2Merge.config.customers
# or
$oXMLCustomers=$oConfig2Merge.selectSingleNode("config/customers")
# Import the Node with the ImportNode Function from System.XML.XMLDocument
$oXMLConfigTarget.appendChild($oXMLDocument.ImportNode($oXMLCustomers,$true))
$oXMLDocument.Save("c:\temp\config.xml")

To be continued…

Michael

9 thoughts on “Powershell: Some basic XML handling with Powershell and .NET”

    1. Hi Anonymous??

      it’s simple

      PS H:\> [ xml ] $oXML=”<test></test>”
      PS H:\> $oXML

      test
      —-

      PS H:\> $oXML.test=”This is the innerText”
      PS H:\> $oXML

      test
      —-
      This is the innerText

      Michael

  1. I just had to do this: all my values are like this
    “”

    Here is the code, this blog was the final piece I needed.

    Thanks,

    $xdoc = (get-content “d:\SFA\SingleFileArchiveService.exe.config”)

    $xdoc.configuration.userSettings.’SingleFileArchiveService.Properties.Settings’

    $xyz = $xdoc.configuration.userSettings.’SingleFileArchiveService.Properties.Settings’.setting | Where-Object {$_.Name -eq ‘RecordingDelay’}
    $xyz.value=”2000″

    $xdoc.Save($path)

    PS… Love the Metallica Reference. You forgot “Document Mustaine”
    /me listening to Megadeth right now…

    1. Hi Theo,

      create your XML “on the fly” as descripted at the end of the post:
      [xml]$oConfig2Merge='<config description=”Users”>
      <customers>
      <user surname=”Campbell” firstname=”Wayne”>Wayne</user>
      <user surname=”Garth” firstname=”Algar”>Garth</user>
      <user surname=”Cheers” firstname=”Phil”>Phil</user>
      </customers>
      </config>’
      The variable $oConfig2Merge contains the XML document.

      and do not call the Save() method?

      Michael

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