functions/utility/New-PSFHashtable.ps1
|
function New-PSFHashtable { <# .SYNOPSIS Creates a new PSFHashtable, which can have a default value set. .DESCRIPTION Creates a new PSFHashtable. This is a type that acts the same as a regular hashtable for most purposes. Its key differentiator is, that it supports defining a default value, in case a key is provided that has not been set before. It also comes with a ".SetDefaultValue($object)" method to later change the default value. Important note: The pseudo-property notation to access values in hashtables also works for a PSFHashtable, but ONLY for keys already defined! The default value requires an INDEX notation. Example: $hashtable = New-PSFHashtable -DefaultValue 42 $hashtable.Foo # nothing $hashtable['Foo'] # 42 .PARAMETER Hashtable An original hashtable to build the PSFHashtable around. This will prepopulate the hashtable with the key/value pairs of the input hashtable. This effectively clones the input hashtable, the new PSFHashtable is not a reference to the original input. .PARAMETER DefaultValue The default value returned by the hashtable, when resolving a key not specified on the hashtable. .PARAMETER PassThru When resolving a key not specified on the hashtable, return the key instead of nothing. .PARAMETER Calculator When resolving a key not specified on the hashtable, use this logic to determine the result. Receives the key as its sole input / argument / $_ .EXAMPLE PS C:\> New-PSFHashtable Returns a simple PSFHashtable, functionally the same as a regular hashtable. It comes with a .SetDefaultValue($object) method to later define a default value. .EXAMPLE PS C:\> New-PSFHashtable -DefaultValue 42 Returns an empty PSFHashtable which will by default return 42. .EXAMPLE PS C:\> New-PSFHashtable -Hashtable $originHash -DefaultValue $false Returns a PSFHashtable that is a copy of the hashtable in $originHash, which will by default return $false when resolving undefined keys. .EXAMPLE PS C:\> New-PSFHashtable -Hashtable $originHash -PassThru Returns a PSFHashtable that is a copy of the hashtable in $originHash, which will by default return the key itself when resolving undefined keys. .EXAMPLE PS C:\> New-PSFHashtable -Calculator { (Get-Volume | Sort-Object SizeRemaining -Descending)[0] } Returns an empty PSFHashtable which will by default return the volume with the most space remaining. #> [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSUseShouldProcessForStateChangingFunctions", "")] [OutputType([PSFramework.Object.PsfHashtable])] [CmdletBinding(DefaultParameterSetName = 'Default')] param ( [Hashtable] $Hashtable = @{ }, [Parameter(ParameterSetName = 'Default')] [object] $DefaultValue, [Parameter(ParameterSetName = 'PassThru')] [switch] $PassThru, [Parameter(ParameterSetName = 'Calculator')] [scriptblock] $Calculator ) process { $result = [PSFramework.Object.PsfHashtable]::new($Hashtable) if ($PSBoundParameters.Keys -contains 'DefaultValue') { $result.SetDefaultValue($DefaultValue) } if ($PassThru) { $result.EnablePassthru() } if ($Calculator) { $result.SetCalculator($Calculator) } $result } } |