adding XML sub-elements

I prefer creating xml by hand, instead of using API to construct it node by node, as imho by hand it will be much more readable and more maintable.

Here is an example:

$pathToConfig = $env:windir + "\Microsoft.NET\Framework64\v4.0.30319\Config\web.config"

$xml = [xml] (type $pathToConfig)

[xml]$appSettingsXml = @"
<appSettings>
    <add key="WebMachineIdentifier" value="$webIdentifier" />
</appSettings>
"@


$xml.configuration.AppendChild($xml.ImportNode($appSettingsXml.appSettings, $true))
$xml.Save($pathToConfig)

Have a look to the following example :

# Document creation
[xml]$xmlDoc = New-Object system.Xml.XmlDocument
$xmlDoc.LoadXml("<?xml version=`"1.0`" encoding=`"utf-8`"?><Racine></Racine>")

# Creation of a node and its text
$xmlElt = $xmlDoc.CreateElement("Machine")
$xmlText = $xmlDoc.CreateTextNode("Mach1")
$xmlElt.AppendChild($xmlText)

# Creation of a sub node
$xmlSubElt = $xmlDoc.CreateElement("Adapters")
$xmlSubText = $xmlDoc.CreateTextNode("Network")
$xmlSubElt.AppendChild($xmlSubText)
$xmlElt.AppendChild($xmlSubElt)

# Creation of an attribute in the principal node
$xmlAtt = $xmlDoc.CreateAttribute("IP")
$xmlAtt.Value = "128.200.1.1"
$xmlElt.Attributes.Append($xmlAtt)

# Add the node to the document
$xmlDoc.LastChild.AppendChild($xmlElt);

# Store to a file 
$xmlDoc.Save("c:\Temp\Temp\Fic.xml")

---

Edited

Remark : Using a relative path in Save will not do what you expect.

Check this code-sample. It has everything you need to create XML from scratch:

function addElement($e1, $name2, $value2, $attr2)
{
    if ($e1.gettype().name -eq "XmlDocument") {$e2 = $e1.CreateElement($name2)}
    else {$e2 = $e1.ownerDocument.CreateElement($name2)}
    if ($attr2) {$e2.setAttribute($value2,$attr2)}
    elseif ($value2) {$e2.InnerText = "$value2"}
    return $e1.AppendChild($e2)
}

function formatXML([xml]$xml)
{
    $sb = New-Object System.Text.StringBuilder
    $sw = New-Object System.IO.StringWriter($sb)
    $wr = New-Object System.Xml.XmlTextWriter($sw)
    $wr.Formatting = [System.Xml.Formatting]::Indented
    $xml.Save($wr)
    return $sb.ToString()
}

...now let's use both functions to create and display a new XML-object:

$xml = New-Object system.Xml.XmlDocument
$xml1 = addElement $xml "a"
$xml2 = addElement $xml1 "b"
$xml3 = addElement $xml2 "c" "value"
$xml3 = addElement $xml2 "d" "attrib" "attrib_value"

write-host `nFormatted XML:`r`n`n(formatXML $xml.OuterXml)

the result looks like this:

Formatted XML:

 <?xml version="1.0" encoding="utf-16"?>
<a>
  <b>
    <c>value</c>
    <d attrib="attrib_value" />
  </b>
</a>