powershell - How do I get properties that ONLY have populated values?

Question

How do I get properties that ONLY have populated values?

So for example if I run

Get-QADUser -Identity "SomeOne" -IncludeAllProperties

the output would of course include.. all properties, including those with and those without values. I want a listing of properties with values only. How is it done generally speaking?

This wouldn't be restricted to Quest Cmdlets, I only use Get-QADUser as an example.

score 11 · Accepted Answer

You could try using the built-in (hidden) property of PowerShell objects called PSObject, which includes a property called Properties, i.e. a list of all properties on the parent object.

Maybe easier with an example. Take Get-Process... a process can have many attributes (properties) with or without values. In order to get just the ones with values you do this:

(Get-Process | Select -First 1).PSObject.Properties | ?{$_.Value -ne $null} | FT Name,Value

Note that I limited this to just the first process returned by Get-Process. We then get all the properties defined on that object, filtering where Value is not null and then displaying just the Name and Value for those properties.

score 9 · Accepted Answer

To complement Charlie Joynt's helpful answer:

Below is convenience function Remove-NullProperties, which creates custom-object copies of its input objects populated with only the non-$null properties of the input objects.

Example use:

# Sample input collection, with 2 objects with different $null-valued
# properties.
$coll = [pscustomobject] @{ one = 'r1c1'; two = $null; three = 'r1c3' },
        [pscustomobject] @{ one = 'r2c1'; two = 'r2c2'; three = $null }

# Output copies containing only non-$null-valued properties.
# NOTE: The `ForEach-Object { Out-String -InputObject $_ }` part is solely
#       there to ensure that *all* resulting properties are shown.
#       With the default output, only the properties found on the FIRST
#       input object would be used in the output table.
$coll | Remove-NullProperties | 
  ForEach-Object { Out-String -InputObject $_ }

This yields the following - note how the respective null-valued properties were removed:

one  three
---  -----
r1c1 r1c3 


one  two 
---  --- 
r2c1 r2c2

Remove-NullProperties source code:

<#
.SYNOPSIS
Removes properties with $null values from custom-object copies of 
the input objects.

.DESCRIPTION
Note that output objects are custom objects that are copies of the input
objects with copies of only those input-object properties that are not $null.

CAVEAT: If you pipe multiple objects to this function, and these objects
        differ in what properties are non-$null-valued, the default output
        format will show only the non-$null-valued properties of the FIRST object.
        Use ... | ForEach-Object { Out-String -InputObject $_ } to avoid
        this problem.

.NOTES
Since the output objects are generally of a distinct type - [pscustomobject] -
and have only NoteProperty members, use of this function only makes sense
with plain-old data objects as input.

.EXAMPLE
> [pscustomobject] @{ one = 1; two = $null; three = 3 } | Remove-NullProperties

one three
--- -----
  1     3

#>
function Remove-NullProperties {

  param(
    [parameter(Mandatory,ValueFromPipeline)]
    [psobject] $InputObject
  )

  process {
    # Create the initially empty output object
    $obj = [pscustomobject]::new()
    # Loop over all input-object properties.
    foreach($prop in $InputObject.psobject.properties) {
      # If a property is non-$null, add it to the output object.
      if ($null -ne $InputObject.$($prop.Name)) {
        Add-Member -InputObject $obj -NotePropertyName $prop.Name -NotePropertyValue $prop.Value
      }
    }
    # Give the output object a type name that reflects the type of the input
    # object prefixed with 'NonNull.' - note that this is purely informational, unless
    # you define a custom output format for this type name.
    $obj.pstypenames.Insert(0, 'NonNull.' + $InputObject.GetType().FullName)
    # Output the output object.
    $obj
  }

}

score 3 · Accepted Answer

These answers didn't work for me in the case of importing an object from an Infoblox csv file. Some values were the empty string, but not null. Testing whether a property is true or not, seems to work better for me. And the result is an object.

$a = [pscustomobject]@{one='hi';two='';three='there'}
$prop = $a.psobject.Properties | where value | foreach name
$a | select $prop

one three
--- -----
hi  there

score 0 · Accepted Answer

You first get its properties (since Get-QADUser depends on AD schema, the properties list is dynamic) with get-member -type property, then filter out those that don't have \{.*(get).*\} in its definition (that is, they are not "gettable"), then enumerate the resultant list by name and filter out nulls.

$someone=Get-QADUser -Identity "SomeOne" -IncludeAllProperties
$members=$someone|get-member -type property| where {$_.definition -match '\{.*(get).*\}'}
foreach ($member in $members) {
    if ($someone[$member.name] -ne $null) {
        write-host $member.name $someone[$member.name] 
    }
}

powershell - How do I get properties that ONLY have populated values?

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