Requiring parameters in PowerShell when another parameter is present

Question

Everything I have read so far tells me that this should work. This is intended to be a script for automating the transfer out of AD accounts. How I would like it to work is if the -TransferHomeDrive switch is set, then it will require names for the old server and new server.

I believe I should be able to do this with a parameter set, however if I just have the single parameter set, plus the default parameters, it will always prompt me for an old and new server. Here is my param statement:

Param( 
    [Parameter(Mandatory=$True, ValueFromPipeline=$True, ValueFromPipelineByPropertyName=$True)]
    [string]$Username,

    [switch]$RetainGroups,

    [Parameter(ParameterSetName='TransferHomeDrive', Mandatory=$False)]
    [switch]$TransferHomeDrive,

    [Parameter(ParameterSetName='TransferHomeDrive', Mandatory=$True)]
    [string]$OldServer,

    [Parameter(ParameterSetName='TransferHomeDrive', Mandatory=$True)]
    [string]$NewServer
)

So, if it were working, you could run

Move-AccountOut -Username JohnSmith -RetainGroups

And it won't schedule a home drive transfer. However, if you were to run

Move-AccountOut -Username JohnSmith -RetainGroups -TransferHomeDrive

It would prompt for OldServer and NewServer.

I've found similar questions, including these, but it's still not working:

PowerShell mandatory parameter depend on other parameter

Having a optional parameter that requires another parameter to be present

I believe that it would work if I created a second parameter set, that included ALL parameters, including Username and RetainGroups, but it seems like according to the other posts that I should be able to have it work the way that I have it written, where Username and RetainGroups are "global" parameters, and OldServer and NewServer are only required when TransferHomeDrive is set

How is this not working currently? Does it not prompt? Does it always prompt? Does it error? — Etan Reisner

user4003407 user4003407 · Accepted Answer · 2015-05-06T21:20:02

In your code you have only one parameter set TransferHomeDrive, you does not have other default parameter set. You should let PowerShell know, that another named parameter set exists, by explicitly declare it in CmdletBinding or Parameter attribute.

[CmdletBinding(DefaultParameterSetName='NoTransferHomeDrive')]
Param( 
    [Parameter(Mandatory=$True, ValueFromPipeline=$True, ValueFromPipelineByPropertyName=$True)]
    [string]$Username,

    [switch]$RetainGroups,

    [Parameter(ParameterSetName='TransferHomeDrive', Mandatory=$False)]
    [switch]$TransferHomeDrive,

    [Parameter(ParameterSetName='TransferHomeDrive', Mandatory=$True)]
    [string]$OldServer,

    [Parameter(ParameterSetName='TransferHomeDrive', Mandatory=$True)]
    [string]$NewServer
)

Requiring parameters in PowerShell when another parameter is present

1 Answers