Powershell - Trigger or suppress Where-Object clause based on boolean

Question

What I'm trying to do

I have a configurable Powershell 5.1 script with the following variable:

[bool]$SourceFilter

Based on the value of this boolean, I may or may not trigger a Where-Object clause in the middle of a pipeline, which is filtering a large and complex Array of objects:

$objectArray <# | Where-Object {$_.Attributes.Value -NotLlike "*this*"} #> | Sort-Object -Property {$_.Attributes.Name}

How do I encode the Where-Object clause to only trigger if $SourceFilter = $true?

---

What I've tried

I've tried encoding the clause as a variable and then using Invoke-Expression to rationalise it into the pipeline, but can't seem to get this working:

$script = '| Where-Object {$_.Attributes.pointsource -NotLike "*AF*"}'
$output = if($SourceFilter)
             {Invoke-Expression "$objectArray $script" | Sort-Object -Property {$_.Attributes.Name}}
          else
             {$objectArray | Sort-Object -Property {$_.Attributes.Name}}

This approach gives me an error which states that the $variable is not recognised as the name of a cmdlet, script or program.

Answer 1

You can have a scriptblock variable set to either your condition or true.

$sb1 = {$true}
$sb2 = {$_ -like 'a*'}

echo hi | where $sb1
hi

echo hi | where $sb2