Export-FormatData

Understanding Export-FormatData in PowerShell

Welcome back to Wahmans Powershell blog! Today we are diving into a lesser-known but powerful cmdlet in PowerShell: Export-FormatData. If you’ve ever created custom object views in PowerShell and wanted to persist them, this cmdlet is for you.

According to Microsoft, Export-FormatData “saves formatting data from the current session in a formatting file.” That means you can define how objects are displayed in the console and save that formatting for reuse later. This can be a game changer when building tools or modules with rich display formats. Let’s break it down with some practical examples, starting with beginner-friendly usage and moving into more advanced scenarios.

What is Formatting Data in PowerShell?

Formatting data tells PowerShell how to display objects returned from commands. This data lives in format.ps1xml files and defines things like table, list, and custom formatting views. Export-FormatData allows you to export that formatting data to a file you can later import using Update-FormatData or load as part of a module.

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Examples of Export-FormatData in Action

Example 1: Export Custom Formatting for a Simple Object (Beginner)

Let’s create a custom object and define how it should be displayed using a formatting view.

$myObject = New-Object PSObject -Property @{ 
    Name = "Wahman"
    Age = 42
    Role = "Blogger"
}

Update-TypeData -TypeName PSObject -MemberType ScriptProperty -MemberName PSTypeNames -Value { "My.Custom.Type" }
$myObject.PSTypeNames.Insert(0, "My.Custom.Type")

$view = @"
<Configuration>
  <ViewDefinitions>
    <View>
      <Name>CustomTable</Name>
      <ViewSelectedBy>
        <TypeName>My.Custom.Type</TypeName>
      </ViewSelectedBy>
      <TableControl>
        <TableHeaders>
          <TableColumnHeader><Label>Name</Label></TableColumnHeader>
          <TableColumnHeader><Label>Role</Label></TableColumnHeader>
        </TableHeaders>
        <TableRowEntries>
          <TableRowEntry>
            <TableColumnItems>
              <TableColumnItem><PropertyName>Name</PropertyName></TableColumnItem>
              <TableColumnItem><PropertyName>Role</PropertyName></TableColumnItem>
            </TableColumnItems>
          </TableRowEntry>
        </TableRowEntries>
      </TableControl>
    </View>
  </ViewDefinitions>
</Configuration>
"@

Set-Content -Path .\MyFormat.xml -Value $view

That’s a manual way of creating formatting XML. But you can use Export-FormatData to do it programmatically instead, like in the next example.

Example 2: Export Custom Type Formatting Dynamically (Intermediate)

# Define a custom format view dynamically
$formatData = New-Object System.Management.Automation.ExtendedTypeDefinition("My.Custom.Type")

# Use Export-FormatData to export that formatting to a file
Export-FormatData -InputObject $formatData -Path ".\MyCustomFormat.ps1xml"

This example shows how Export-FormatData can output the internal format data to a file. You can then include that .ps1xml in your module folder and make your tools much more user-friendly in output.

Example 3: Export Multiple Custom Views (Advanced)

# Get all currently loaded type formatting info
$formatData = Get-FormatData | Where-Object TypeNames -like "My.*"

# Export them all to a single formatting file
Export-FormatData -InputObject $formatData -Path ".\CustomFormats.ps1xml" -Force

This script will extract all custom formatting views starting with My. and export them in one file. It’s extremely useful when building a module with multiple custom types.

Example 4: Combine With a Module Manifest (Expert)

# After exporting your format file, include it in your module manifest
New-ModuleManifest -Path ".\MyModule.psd1" \
    -RootModule "MyModule.psm1" \
    -FormatsToProcess @(".\MyCustomFormat.ps1xml")

Now when someone installs your module, PowerShell automatically loads your formatting definitions, giving users a beautifully formatted experience out of the box!

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Final Thoughts

Export-FormatData is a powerful cmdlet that helps make your PowerShell modules and scripts more professional and user-friendly by preserving custom formatting for your objects. Whether you’re a beginner just learning about formatting or an advanced user designing complex tools, it’s a valuable addition to your scripting toolkit.

Happy scripting, and I will see you in the next post!