Add-member scriptmethod dynamic validate set

Stephaneschaumburg 

Sorry, I've re-read the question now.

Functions and methods are two different concepts and I don't believe PowerShell currently is designed to attempt parameter inspection on methods.

For example, if I called the code I dropped in above "Get-ScreenResolution" and then added it to a PSCustomObject like this:

$o = [PSCustomObject] @{ Name = "Fred"; }
$o | Add-Member -MemberType ScriptMethod -Name GetScreenResolution -Value { Param($Mode); Get-ScreenResolution -Mode $Mode; }

And then finally inspected the difference using Get-Member, like this (for both the function and then the scriptmethod):

${function:Get-ScreenResolution} | gm;
$o.GetScreenResolution | gm;

Then you get back a [System.Management.Automation.ScriptBlock] for the function (line 1) and a [System.Management.Automation.PSScriptMethod] for the scriptmethod (line 2) - and that difference is expected, and also why you're not likely to get tab completion, since you're not looking at the same kind of thing.

Maybe if PowerShell walked the chain and further inspected the "Script" attribute of the [System.Management.Automation.PSScriptMethod], it could probably do it, but I haven't read or seen anything to suggest it's possible to make it do so, and certainly not in a user-interactive manner.

So, when you call a function, you're calling it directly, hence tab completion is acknowledged. When you call a function added as a scriptmethod, you're calling the function indirectly via the PSScriptMethod instance.

Cheers,

Lain