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PowerShell 4.0 Wishlist - Select-Object Enhancement

I mostly like the way Select-Object allows you to create custom objects and properties. However, I really wish it was simpler to create properties with ScriptBlock values without the lengthy Hashtable definition.

If only Select-Object would implement something like this so you can define a property ScriptBlock without the long Hashtable definition. Similar to how this custom function I wrote allows you to define a property name as the Key of the Hashtable and the value as the ScriptBlock or name of the property.

Wishlists are usually wishful thinking, there are probably reasons why Select-Object behaves like it does, it isn't that bad since you can short-hand the keys but it just doesn't seem as fluid. Here is to wishing for a better Select-Object.
  1. function ConvertTo-PSCustomObject {  
  2.     [CmdletBinding()]  
  3.     param(  
  4.         [ValidateNotNullOrEmpty()]  
  5.         [Parameter(Mandatory = $true, Position = 0)]  
  6.         [Array] $Property,  
  7.   
  8.         [Parameter(Mandatory = $true, ValueFromPipeline = $true)]  
  9.         $InputObject  
  10.     )  
  11.   
  12.     begin {  
  13.         $Properties = $Property |% {  
  14.             if ($_ -is [Hashtable]) {  
  15.                 $_.GetEnumerator() |% {  
  16.                     if ($_.Value -is [ScriptBlock]) {  
  17.                         @{Name="$($_.Key)";Expression=$_.Value}  
  18.                     } else {  
  19.                         @{Name="$($_.Key)";Expression=[ScriptBlock]::Create("`$_.'$($_.Value)'")}  
  20.                     }  
  21.                 }  
  22.             } else {  
  23.                 $_  
  24.             }  
  25.         }  
  26.     }  
  27.   
  28.     process {  
  29.         $InputObject | Select-Object -Property $Properties  
  30.     }  
  31. }  
  32.   
  33. gci $ENV:TEMP -Directory | ConvertTo-PSCustomObject Extension,@{FileName='Name'},@{Age={(Get-Date) - $_.CreationTime}}  

Comments

  1. I have a similar request for PSCustomObject literals! I made a Gist to demonstrate how this would work by creating a new function called New-PSObject but it'd be awesome if the object literal syntax also worked.

    One difference with mine is it determines whether the scriptblock should be created as a ScriptMethod or ScriptProperty based on the presence of a param() block.

    https://gist.github.com/josheinstein/3859588

    ReplyDelete

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