Can you set an object's DefaultDisplayPropertySet in a PowerShell v2 script?
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21-09-2019 - |
Question
Here is a blog post from Kirk Munro that explains how a script can set the DefaultDisplayPropertySet on its output objects:
Essential PowerShell: Define default properties for custom objects
His technique and example code doesn't appear to work in PowerShell v2. (Note, I have PowerTab and PSCX installed--perhaps those could be interfering.)
Anyone know how to get this to work on PowerShell v2?
UPDATE: Here's the example from the blog post, which isn't working for me (note, I've corrected the single quote characters):
$myObject = New-Object PSObject
$myObject | Add-Member NoteProperty Name 'My Object'
$myObject | Add-Member NoteProperty Property1 1
$myObject | Add-Member NoteProperty Property2 2
$myObject | Add-Member NoteProperty Property3 3
$myObject | Add-Member NoteProperty Property4 4
$myObject | Add-Member NoteProperty Property5 5
$myObject
## Output:
# Name : My Object
# Property1 : 1
# Property2 : 2
# Property3 : 3
# Property4 : 4
# Property5 : 5
$defaultProperties = @('Name','Property2','Property4')
$defaultDisplayPropertySet = New-Object System.Management.Automation.PSPropertySet('DefaultDisplayPropertySet',[string[]]$defaultProperties)
$PSStandardMembers = [System.Management.Automation.PSMemberInfo[]]@($defaultDisplayPropertySet)
$myObject | Add-Member MemberSet PSStandardMembers $PSStandardMembers
$myObject
## Output:
# Name : My Object
# Property1 : 1
# Property2 : 2
# Property3 : 3
# Property4 : 4
# Property5 : 5
The output should not be the same after adding DefaultDisplayPropertySet (i.e., it should only have Name, Property2, and Property4).
Solution
Can you give an example of your non-working code? This should work perfectly in v2, if not, you've found a bug.
UPDATE:
(removed comments about quoting)
I've confirmed with the powershell team that this is indeed a regression (bug).
You can vote on the issue's importance to you here:
https://connect.microsoft.com/PowerShell/feedback/ViewFeedback.aspx?FeedbackID=487938
Thanks,
-Oisin (powershell MVP)
OTHER TIPS
Here is a solution I created to work around this issue:
function Set-PSObjectDefaultProperties {
param(
[PSObject]$Object,
[string[]]$DefaultProperties
)
$name = $Object.PSObject.TypeNames[0]
$xml = "<?xml version='1.0' encoding='utf-8' ?><Types><Type>"
$xml += "<Name>$($name)</Name>"
$xml += "<Members><MemberSet><Name>PSStandardMembers</Name><Members>"
$xml += "<PropertySet><Name>DefaultDisplayPropertySet</Name><ReferencedProperties>"
foreach( $default in $DefaultProperties ) {
$xml += "<Name>$($default)</Name>"
}
$xml += "</ReferencedProperties></PropertySet></Members></MemberSet></Members>"
$xml += "</Type></Types>"
$file = "$($env:Temp)\$name.ps1xml"
Out-File -FilePath $file -Encoding "UTF8" -InputObject $xml -Force
$typeLoaded = $host.Runspace.RunspaceConfiguration.Types | where { $_.FileName -eq $file }
if( $typeLoaded -ne $null ) {
Write-Verbose "Type Loaded"
Update-TypeData
}
else {
Update-TypeData $file
}
}
Now you can use the following to create your custom object and set the default properties in PowerShell V2:
$myObject = New-Object PSObject
$myObject | Add-Member NoteProperty Name 'My Object'
$myObject | Add-Member NoteProperty Property1 1
$myObject | Add-Member NoteProperty Property2 2
$myObject | Add-Member NoteProperty Property3 3
$myObject | Add-Member NoteProperty Property4 4
$myObject | Add-Member NoteProperty Property5 5
$myObject
## Output:
# Name : My Object
# Property1 : 1
# Property2 : 2
# Property3 : 3
# Property4 : 4
# Property5 : 5
$defaultProperties = @('Name','Property2','Property4')
Set-PSObjectDefaultProperties $myObject $defaultProperties
$myObject
## Output:
#Name Property2 Property4
#---- --------- ---------
#My Object 2 4
It is also available via PoshCode: Set-PSObjectDefaultProperties
I get the same results as you do - it displays all 5 properties. I'm running Powershell 2.0 RC on Vista. I don't have PowerTab or PSCX installed.