Use-NullCoalescing.psm1
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<#PSScriptInfo
.VERSION 1.0.1 .GUID 3dbe34cb-6c77-4df2-a983-14fac15b78ce .AUTHOR Anthony J. Raymond .COMPANYNAME .COPYRIGHT (c) 2022 Anthony J. Raymond .TAGS operators null-coalescing ?? c# csharp .LICENSEURI https://github.com/CodeAJGit/posh/blob/main/LICENSE .PROJECTURI https://github.com/CodeAJGit/posh .ICONURI .EXTERNALMODULEDEPENDENCIES .REQUIREDSCRIPTS .EXTERNALSCRIPTDEPENDENCIES .RELEASENOTES 20220303-AJR: v1.0.0 - Initial Release 20220305-AJR: v1.0.1 - Updated Metadata .PRIVATEDATA #> <# .DESCRIPTION Impliments the Null-coalescing operator (??) using the pipeline. .EXAMPLE $null | ?? "InputNull" .EXAMPLE $null, "value", $null | ?? "InputNull" -ParseElements .PARAMETER InputObject Specifies the <condition> expression to be evaluated and returned if not null. .PARAMETER IfNull Specifies the expression to be executed if the <condition> expression is null. .PARAMETER ParseElements <Optional> Specifies to evaluate each collection element independently. .LINK https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/null-coalescing-operator .LINK https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_operators .LINK https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_pipelines #> function Use-NullCoalescing { [CmdletBinding()] [OutputType([object])] ## PARAMETERS ############################################################# param ( [Parameter( Mandatory, ValueFromPipeline )] [AllowNull()] [AllowEmptyString()] [AllowEmptyCollection()] [object] $InputObject, [Parameter( Position = 0, Mandatory )] [object] $IfNull, [switch] $ParseElements ) ## FUNCTIONS AND SCRIPT VARIABLES ######################################### begin { $InputObjects = New-Object -TypeName System.Collections.Generic.List[object] } ## EXECUTION ############################################################## process { $null = $InputObjects.Add($InputObject) } end { # I know it looks weird but we gotta handle a lot of "NULL" stuff, catches: # $null; empty strings; empty collections; $null, empty string, and empty collections in collections # examples: $null, "", @(), @{}, @($null), @(""), @(@()), @(@{}) # yes, $null is on the right on purpose. we want to pull out $null if $_ is a collection # by that same token "" is on the left becuase of how comparisons work with $false and 0 switch ($ParseElements) { $true { foreach ($Object in $InputObjects) { if (($IfNotNull = $Object | Where-Object { ($_ -ne $null) -and ("" -ne $_) -and ($_.Count -gt 0) -and (@($_).GetEnumerator().Count -gt 0) }).Count -gt 0) { $IfNotNull } else { $IfNull } } } $false { if (($IfNotNull = $InputObjects | Where-Object { ($_ -ne $null) -and ("" -ne $_) -and ($_.Count -gt 0) -and (@($_).GetEnumerator().Count -gt 0) }).Count -gt 0) { $IfNotNull } else { $IfNull } } } ## CLEAN UP ############################################################### [void]([System.GC]::GetTotalMemory($true)) } } Set-Alias -Name ?? -Value Use-NullCoalescing Export-ModuleMember -Function Use-NullCoalescing -Alias ?? |