Using PowerShell to Read and Write XML

This blog provides a simple example of using PowerShell to read and write XML nodes and attribute names.

Using PowerShell to Write XML

In this example, we first create a new [System.Xml.XmlDocument] object to represent our XML document. We then create a root node and append it to the document. We create a child node, add an attribute and inner text, and append it to the root node.

Finally, we save the XML document to a file using the Save method.

# Create new XML document
$xml = New-Object -TypeName System.Xml.XmlDocument

# Create root node
$root = $xml.CreateElement("RootNode")
$xml.AppendChild($root)

# Create child node with attribute and value
$child = $xml.CreateElement("ChildNode")
$child.SetAttribute("AttributeName", "AttributeValue")
$child.InnerText = "Inner text"
$root.AppendChild($child)

# Save XML to file
$xml.Save("C:\alkane\example.xml")

Using PowerShell to Read XML

In this example, we first load an XML file using the Get-Content cmdlet and cast it as an [xml] object using the PowerShell type accelerator. We can then access specific elements and attributes within the XML document using dot notation.

# Load XML file
[xml]$xml = Get-Content -Path C:\alkane\example.xml

# Access XML elements and attributes
$xml.RootNode.ChildNode.AttributeName
$xml.RootNode.ChildNode.InnerText

Using PowerShell to Iterate Through XML Nodes and Attributes

Let’s suppose our XML file has more than one child node like so:

# Create new XML document
$xml = New-Object -TypeName System.Xml.XmlDocument

# Create root node
$root = $xml.CreateElement("RootNode")
$xml.AppendChild($root)

# Create child node with attribute and value
$child = $xml.CreateElement("ChildNode")
$child.SetAttribute("AttributeName", "AttributeValue1")
$child.InnerText = "Inner text 1"
$root.AppendChild($child)

# Create another child node with attribute and value
$child = $xml.CreateElement("ChildNode")
$child.SetAttribute("AttributeName", "AttributeValue2")
$child.InnerText = "Inner text 2"
$root.AppendChild($child)

# Save XML to file
$xml.Save("C:\alkane\example.xml")

We might then want to loop through these child nodes to read each node text and attribute.  We can do this like so:

# Load XML file
[xml]$xml = Get-Content -Path C:\alkane\example.xml

# Loop through nodes and attributes
foreach ($node in $xml.RootNode.ChildNodes) {
    Write-Host "Node name: $($node.Name)"
    Write-Host "Node value: $($node.InnerText)"
    
    foreach ($attribute in $node.Attributes) {
        Write-Host "Attribute name: $($attribute.Name)"
        Write-Host "Attribute value: $($attribute.Value)"
    }
}