Use ValidateSet with the contents loaded from a CSV file - validation

Question

I really like the way that ValidateSet works. It proposes the options as a list while you type your Cmdlet in the PowerShell ISE.
I would like to know if it's possible to retrieve values from a CSV-file (Import-CSV) and use them in the Param block so they become available in the drop down box of the PowerShell ISE when constructing the Cmdlet arguments? A bit in the same way that $Type works now, but then with values from the import file.
Function New-Name {
Param (
[parameter(Position=0, Mandatory=$true)]
[ValidateSet('Mailbox','Distribution','Folder','Role')]
[String]$Type,
[parameter(Position=1,Mandatory=$true)]
[String]$Name
)
Process { 'Foo' }
}

Answer 1

Here is something you can start with:
function New-Name {
param (
[parameter(Position=0, Mandatory=$true)]
[String]$Name
)
dynamicparam {
$attributes = new-object System.Management.Automation.ParameterAttribute
$attributes.ParameterSetName = "__AllParameterSets"
$attributes.Mandatory = $true
$attributeCollection = new-object -Type System.Collections.ObjectModel.Collection[System.Attribute]
$attributeCollection.Add($attributes)
$values = #('MailBox', 'Tralala', 'Trilili') # your Import-Csv here
$ValidateSet = new-object System.Management.Automation.ValidateSetAttribute($values)
$attributeCollection.Add($ValidateSet)
$dynParam1 = new-object -Type System.Management.Automation.RuntimeDefinedParameter("Type", [string], $attributeCollection)
$paramDictionary = new-object -Type System.Management.Automation.RuntimeDefinedParameterDictionary
$paramDictionary.Add("Type", $dynParam1)
return $paramDictionary
}
process { 'Foo' }
}
Credits where credits are due, this largely comes from the following article from the Scripting Guy.
The code isn't pretty, but it does what you want.

Answer 2

I know this post is quite old, but with Powershell 6.2 and above you can use a .NET class at the beginning of the script and have the set controlled by a csv for example.
This article hear does an excellent job of explaining:
https://adamtheautomator.com/powershell-validateset/

Answer 3

I prefer TabExpansion++ module though this doesn't technically validate, it has some nice functionality...
Here's an example of an msbuild overloaded command to add some intellisense for projects
Register-ArgumentCompleter -CommandName "msbuild" -ParameterName "target" -ScriptBlock {
param($commandName, $parameterName, $wordToComplete, $commandAst, $fakeBoundParameter)
$projectName = $fakeBoundParameter['project']
$projectFile = Join-Path (Get-Location) $projectName
$projectXml = [xml](Get-Content $projectFile)
$targets = $projectXml.Project.Target | Where-Object { $_.Name.ToString().StartsWith($wordToComplete) }
foreach($target in $projectXml.Project.Target)
{
New-CompletionResult -CompletionText "$($target.Name)"
}
}