Powershell C# Extension How to Set the DefaultDisplayProperty when returning data with Write Object

Question

I have created a PowerShell cmdlet in C#:

using System.Management.Automation;
using thosepeskyexternalclasses

[Cmdlet(VerbsCommon.Get, "GetActivity", SupportsTransactions = false)]
public class GetActivity : PSCmdlet
{
    protected override void ProcessRecord()
    {
        base.ProcessRecord();
        // Get the activities
        List<activity> activities = GetActivities();

        WriteObject(activities);

    }
}

The activity object does not contain a name property so when it is returned and displayed it is using the ID Value. This can be resolved by using the following command:

Update-TypeData -TypeName activity -DefaultDisplayProperty otherprop

This has to be done every time I start a new PowerShell session. Is there a way to do the equivalent function when my extension module is loaded?

The conventional approach is to package your binary module as a directory-based module with a manifest, and bundle a *.Types.ps1xml type-extension file with it. — mklement0
– mklement0, Commented Aug 6, 2024 at 19:31
I followed this guidance and have successfully solved my use case. Thanks! — William Holmes
– William Holmes, Commented Aug 7, 2024 at 13:55

Santiago Squarzon · Accepted Answer · 2024-10-15 13:01:16Z

0

You can add a static ctor to your cmdlet where you can invoke Update-TypeData using a PowerShell instance:

using System.Collections.Generic;
using System.Management.Automation;
using thosepeskyexternalclasses;

[Cmdlet(VerbsCommon.Get, "Activity", SupportsTransactions = false)]
public sealed class GetActivity : PSCmdlet
{
    static GetActivity()
    {
        // set the `DefaultDisplayProperty` for the `activity` type the first time this cmdlet is called
        using PowerShell powershell = PowerShell.Create(RunspaceMode.CurrentRunspace);
        powershell
            .AddCommand("Update-TypeData")
            .AddParameters(new Dictionary<string, string>
            {
                ["TypeName"] = "thosepeskyexternalclasses.activity",
                ["DefaultDisplayProperty"] = "otherprop" // <- update with actual property name!
            })
            .Invoke();
    }

    protected override void ProcessRecord()
    {
        // Get the activities
        List<activity> activities = GetActivities();
        WriteObject(activities);
    }
}

As mklement0 states in a comment, another option considering this cmdlet could be part of a binary module, best practice would be to have a *.Types.ps1xml file where you define the default display property. Then you add this file's path to TypesToProcess of your Module Manifest.

For this specific example, the XML would be something like:

<?xml version="1.0" encoding="utf-8"?>
<Types>
  <Type>
    <Name>thosepeskyexternalclasses.activity</Name>
    <Members>
      <MemberSet>
        <Name>PSStandardMembers</Name>
        <Members>
          <NoteProperty>
            <Name>DefaultDisplayProperty</Name>
            <!-- update with actual property name here -->
            <Value>otherprop</Value>
          </NoteProperty>
        </Members>
      </MemberSet>
    </Members>
  </Type>
</Types>

edited Oct 15, 2024 at 13:01

answered Aug 6, 2024 at 19:20

Santiago Squarzon

65.6k5 gold badges26 silver badges60 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Santiago Squarzon Over a year ago

@mklement0 thanks for the +1 and np, was worth the research there are absolutely 0 examples in google reg. DefaultDisplayProperty, only for DefaultDisplayPropertySet. maybe worth submitting an issue to the docs repo to add an example

William Holmes Over a year ago

Thanks for the guidance. Both of the described methods resolved the issue. I have created a Module Manifest as it seems like best practice.

Collectives™ on Stack Overflow

Powershell C# Extension How to Set the DefaultDisplayProperty when returning data with Write Object

1 Answer 1

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related