Using HelpMessage in Parameter Attributes

Question

_{Wednesday, November 4, 2015 5:01 PM}

I am attempting to use the HelpMessage attribute for my PowerShell parameters, however, when I am prompted for the parameters while running my PowerShell script, I do not see any Help Message that provides insight about what to enter for my parameters.

[CmdletBinding()]
Param(
[Parameter(Mandatory=$True,HelpMessage="Please enter the SQL sysadmin username", Position=1)]
[string]$SQLUsername
)

How do I get Help information that informs the user what to enter for a particular parameter when they are prompted for a particular parameter?

Please advise.

All replies (2)

_{Wednesday, November 4, 2015 5:53 PM ✅Answered | 3 votes}

You're not going to see the option to show the help message unless someone doesn't enter a value for your mandatory -SQLUsername parameter. And even if they don't enter a value, they're going to have to enter !? to actually be presented with your help message. Take a look at the image I've included when running jrv's function.

jrv's idea to use the ValidateSet attribute is a nice option to display the acceptable values from this parameter, by using Tab. Also be sure to include comment-based help, so users can run Get-Help against your function and find out what you function requires. Help messages are nice, but they are often not included because full and complete comment-based help, to include some examples, is where people should go that need assistance using a function or cmdlet.

_{Wednesday, November 4, 2015 5:11 PM}

Use auto-complete with "ValidateSet"

function Test-Param{
    [CmdletBinding()]
        Param(
            [ValidateSet('Admin1','Admin2','Admin3')]
            [Parameter(
                Mandatory=$True,
                HelpMessage="Please enter the SQL sysadmin username",
                Position=1
            )][string]$SQLUsername
        )
}

Test-Admin -SQLUsername <tab>

Just hit <tab> to fill in.

\(ツ)_/