PowerShell – pass ordered hashtable to function

How do I pass an ordered hash table to a function?

The following error was thrown: "ordered attributes can only be specified on Hash text nodes."

function doStuff {
    Param (
        [ordered]$theOrderedHashtable
    )
    $theOrderedHashtable
}

$datFileWithMinSizes  = [ordered]@{"FileA.DAT" = "4"; "FileB.DAT" = "5"; "FileC.DAT" = "91" ; "FileD.DAT" = "847"  }


doStuff -theOrderedHashtable $datFileWithMinSizes

The following do not maintain the correct order:

function doStuff {
    Param (
        [Hashtable]$theOrderedHashtable = [ordered]@{}
    )
    $theOrderedHashtable
}

$datFileWithMinSizes  = [ordered]@{"FileA.DAT" = "4"; "FileB.DAT" = "5"; "FileC.DAT" = "91" ; "FileD.DAT" = "847"  }


doStuff -theOrderedHashtable $datFileWithMinSizes

The only way I can use it at present is not to specify the type as follows, but I want to specify the type:

function doStuff {
    Param (
        $theOrderedHashtable
    )
    $theOrderedHashtable
}

$datFileWithMinSizes  = [ordered]@{"FileA.DAT" = "4"; "FileB.DAT" = "5"; "FileC.DAT" = "91" ; "FileD.DAT" = "847"  }


doStuff -theOrderedHashtable $datFileWithMinSizes

Solution

Use full type name:

function Do-Stuff {
    param(
        [System.Collections.Specialized.OrderedDictionary]$OrderedHashtable
    )
    $OrderedHashtable
}

To support regular hash tables and ordered dictionaries, you must use a separate parameter set: use the [system. Collections. Idictionary] interface, such as suggested by Briant

function Do-Stuff {
    [CmdletBinding(DefaultParameterSetName='Ordered')]
    param(
        [Parameter(Mandatory=$true,Position=0,ParameterSetName='Ordered')]
        [System.Collections.Specialized.OrderedDictionary]$OrderedHashtable,[Parameter(Mandatory=$true,ParameterSetName='Hashtable')]
        [hashtable]$Hashtable
    )
    if($PSCmdlet.ParameterSetName -eq 'Hashtable'){
        $OrderedHashtable = $Hashtable
    }
    $OrderedHashtable
}