Add XML Element and Attribute with value

Question

I would like to add <logFile directory="D:\Logs\HTTP\example1" /> to each of the site element if it doesn't have it. I have already created a scrip but it doesn't seem to be recognizing the CreateElement method on a foreach object in the xml file it only has .SetAttribute and SetAttributeNode.

$path = "I:\Projects\applicationHostBackUp.config"

$xpath = "/configuration/system.applicationHost/sites/site"

$selector = Select-Xml -Path $path -XPath $xpath | Select-Object -ExpandProperty Node

foreach($object in $selector) {
    if($object -match $object.logFile) {

    }
}

<configuration>
  <system.applicationHost>
    <sites>
           <site name="AppExample" id="3" serverAutoStart="true">
                <application path="/" applicationPool="exampleApp">
                    <virtualDirectory path="/" physicalPath="F:\Web" />
                </application>
                <bindings>
                    <binding protocol="http" bindingInformation="241" />
                </bindings>
                <logFile directory="D:\Logs\HTTP\exampleApp" />
            </site>
           <site name="AppExample2" id="51" serverAutoStart="true">
                <application path="/" applicationPool="exampleApp2">
                    <virtualDirectory path="/" physicalPath="F:\Web" />
                </application>
                <bindings>
                    <binding protocol="http" bindingInformation="241" />
                </bindings>
            </site>
           <site name="AppExample3" id="521" serverAutoStart="true">
                <application path="/" applicationPool="exampleApp3">
                    <virtualDirectory path="/" physicalPath="F:\Web" />
                </application>
                <bindings>
                    <binding protocol="http" bindingInformation="241" />
                </bindings>
            </site>
    </sites>
  </system.applicationHost>
</configuration>

Answer 1

This works:

1. Find all sites without a logFile element
2. If the logFile element not exists - create a new one
3. Create a new attribute Directory and set the value
4. Add the Directory attribute to the logFile element

5. Append the logfile element to the the site element

   $dataFilePath = "I:\Projects\applicationHostBackUp.config"
   
   [xml]$data = Get-content -Path $dataFilePath
   
   foreach ($item in $data.configuration.'system.applicationHost'.sites.site){
   
     if(!$item.logFile) {
       $logFileElement = $data.CreateElement("logFile")
       $directoryAttribute = $data.CreateAttribute("directory")      
   
       $directoryAttribute.psbase.value = "D:\Logs\HTTP\$($item.name)"
       $logFileElement.SetAttributeNode($directoryAttribute)
       $item.AppendChild($logFileElement)
     }
   }
   
   $data.Save($dataFilePath)