Learn PowerShell Core 6.0

Custom type extensions

PowerShell types are already very useful, but sometimes you will need to extend them with additional properties, for example. You already know that this is possible to use the Add-Member cmdlet to extend each object. However, this approach does not scale well.

If you know the type that needs to be extended, you might want to consider using custom type extensions. As with format data in the previous section, you have the opportunity to override existing types by prepending your custom data and appending type extensions:

$typeDefinition = @'<Types><Type>  <Name>System.IO.FileInfo</Name>  <Members>  <ScriptProperty>    <Name>Hash</Name>        <GetScriptBlock>Get-FileHash -Path $this.FullName</GetScriptBlock>    </ScriptProperty> </Members> ...