Execute powershell command with arguments from script

Question

this is hashtable in my powershell script (data extracted using Get-PSReadlineOption):

$theme = @{}
$theme["CommentForegroundColor"] = "DarkGreen"
$theme["CommentBackgroundColor"] = "Black"
$theme["KeywordForegroundColor"] = "Green"
$theme["KeywordBackgroundColor"] = "Black"

I am trying to set powershell theme colors using Set-PSReadlineOption command:

foreach ($colorTokenKey in $theme.keys) {
    $c=$theme[$colorTokenKey]
    echo "$colorTokenKey will be set to $c"
    $colorTokenArgs = $colorTokenKey.Replace("ForegroundColor"," -ForegroundColor")
    $colorTokenArgs = $colorTokenArgs.Replace("BackgroundColor"," -BackgroundColor")
    $colorTokenArgs = $colorTokenArgs.Split(" ")
    $tokenKind = $colorTokenArgs[0]
    $tokenForegroundOrBackground = $colorTokenArgs[1]
    $params = "-TokenKind $tokenKind $tokenForegroundOrBackground $c"
    echo $params
    & Set-PSReadlineOption $params
}

But when I run this, I get

CommandBackgroundColor will be set to White
-TokenKind Command -BackgroundColor White
Set-PSReadlineOption : Cannot bind parameter 'TokenKind'. Cannot convert value "-Tok
enKind Command -BackgroundColor White" to type "Microsoft.PowerShell.TokenClassifica
tion". Error: "Unable to match the identifier name -TokenKind Command -BackgroundCol
or White to a valid enumerator name. Specify one of the following enumerator names a
nd try again:
None, Comment, Keyword, String, Operator, Variable, Command, Parameter, Type, Number
, Member"
At C:\Users\...\PowerShellColors.ps1:88 char:28
+     & Set-PSReadlineOption $params

What I am doing wrong?

Answer 1

You are passing all of your arguments as a single string, which is not what you want.

What you want to do is called splatting.

Change your last lines to this:

$params = @{
    "TokenKind" = $tokenKind
    $tokenForegroundOrBackground = $c
}
Set-PSReadlineOption @params

Also, mind that you have to pass the parameters without the leading -! So you would have to change this too:

$colorTokenArgs = $colorTokenKey.Replace("ForegroundColor"," ForegroundColor")
$colorTokenArgs = $colorTokenArgs.Replace("BackgroundColor"," BackgroundColor")

(Or do maybe define it differently in the first place.)

A somewhat hacky alternative would be using Invoke-Expression, which executes the string as a command:

Invoke-Expression "Set-PSReadlineOption $params"