Let's say I have a function like:
function Authenticate
{
param
(
[ValidateSet('WindowsAuthentication','UsernameAndPassword')]
[string]$AuthenticationType,
[Parameter(ParameterSetName='ParamSet1')]
[string]$Username,
[Parameter(ParameterSetName='ParamSet1')]
[string]$Password
)
..
}
And I would like to enforce these rules:
ParamSet1
mandatory if $AuthenticationType = 'UsernameAndPassword'
ParamSet1
entirely if $AuthenticationType = 'WindowsAuthentication'
It this possible?
Using the link from Tim Ferrill's answer, I created the following function to help create dynamic parameters:
function New-DynamicParameter
{
[CmdletBinding(DefaultParameterSetName = 'Core')]
param
(
[Parameter(Mandatory = $true, ValueFromPipeline = $true)][string] $Name,
[Parameter(Mandatory = $true, ParameterSetName = 'Core')][Parameter(Mandatory = $true, ParameterSetName = 'ValidateSet')][type] $Type,
[Parameter(Mandatory = $false)][string] $ParameterSetName = '__AllParameterSets',
[Parameter(Mandatory = $false)][bool] $Mandatory = $false,
[Parameter(Mandatory = $false)][int] $Position,
[Parameter(Mandatory = $false)][bool] $ValueFromPipelineByPropertyName = $false,
[Parameter(Mandatory = $false)][string] $HelpMessage,
[Parameter(Mandatory = $true, ParameterSetName = 'ValidateSet')][string[]] $ValidateSet,
[Parameter(Mandatory = $false, ParameterSetName = 'ValidateSet')][bool] $IgnoreCase = $true
)
process
{
# Define Parameter Attributes
$ParameterAttribute = New-Object System.Management.Automation.ParameterAttribute
$ParameterAttribute.ParameterSetName = $ParameterSetName
$ParameterAttribute.Mandatory = $Mandatory
$ParameterAttribute.Position = $Position
$ParameterAttribute.ValueFromPipelineByPropertyName = $ValueFromPipelineByPropertyName
$ParameterAttribute.HelpMessage = $HelpMessage
# Define Parameter Validation Options if ValidateSet set was used
if ($PSCmdlet.ParameterSetName -eq 'ValidateSet')
{
$ParameterValidateSet = New-Object System.Management.Automation.ValidateSetAttribute -ArgumentList $ValidateSet -Strict (!$IgnoreCase)
}
# Add Parameter Attributes and ValidateSet to an Attribute Collection
$AttributeCollection = New-Object Collections.ObjectModel.Collection[System.Attribute]
$AttributeCollection.Add($ParameterAttribute)
$AttributeCollection.Add($ParameterValidateSet)
# Add parameter to parameter list
$Parameter = New-Object System.Management.Automation.RuntimeDefinedParameter -ArgumentList @($Name, $Type, $AttributeCollection)
# Expose parameter to the namespace
$ParameterDictionary = New-Object System.Management.Automation.RuntimeDefinedParameterDictionary
$ParameterDictionary.Add($Name, $Parameter)
return $ParameterDictionary
}
}
And solved my particular problem in the following way:
function Authenticate
{
param
(
[ValidateSet('WindowsAuthentication','UsernameAndPassword')][string] $AuthenticationType,
)
DynamicParam
{
if ($AuthenticationType -eq 'UsernameAndPassword')
{
New-DynamicParameter Username [string] -Mandatory $true
New-DynamicParameter Password [string] -Mandatory $true
}
}
...
}
It became unneeded to have a parameter set when using Dynamic Parameter so I removed the parameter set.