Can anyone advise on the following?  I am trying to pipe the property Name from Get-ADComputer to a custom made function...

        [Parameter(Mandatory=$true,
                   ValueFromPipeline=$true,
                   ValueFromPipelineByPropertyName=$true,
                   Position=0)]
        [ValidateNotNull()]
        [ValidateNotNullOrEmpty()]
        [Alias('HostName','Server','IPAddress','CN','Name')]
        [string[]]$ComputerName

The error is a blank ComputerName parameter...

Cannot validate argument on parameter 'ComputerName'. The argument is null or empty. Provide anargument that is not null or empty, and then try the command again.

Since you have made the parameter mandatory, i believe there is no need to use either [ValidateNotNull()] or [ValidateNotNullOrEmpty()] attributes.

        [Parameter(Mandatory=$true,
                   ValueFromPipeline=$true,
                   ValueFromPipelineByPropertyName=$true,
                   Position=0)]
        [Alias('HostName','Server','IPAddress','CN','Name')]
        [string[]]$ComputerName

Also, please make sure the property name from Get-ADComputer is nither Null or empty.

• Edited by mukesh-kumar 15 hours 17 minutes ago

Since you have made the parameter mandatory, i believe there is no need to use either [ValidateNotNull()] or [ValidateNotNullOrEmpty()] attributes.

        [Parameter(Mandatory=$true,
                   ValueFromPipeline=$true,
                   ValueFromPipelineByPropertyName=$true,
                   Position=0)]
        [Alias('HostName','Server','IPAddress','CN','Name')]
        [string[]]$ComputerName

Also, please make sure the property name from Get-ADComputer is nither Null or empty.

• Edited by mukesh-kumar 15 hours 9 minutes ago

Correct however the error message is clearer when declaring validation.

Without...

Cannot bind argument to parameter 'ComputerName' because it is an empty array.

This isn't my issue anyway. I just want to know what I need to change in order for my function to allow me to use the Name from Get-ADComputer into my functions ComputerName property.

did you expanded the property ? 

Get-ADComputer -Filter * | Select-Object -ExpandProperty Name

• Edited by mukesh-kumar 14 hours 49 minutes ago

did you expanded the property ? 

Get-ADComputer -Filter * | Select-Object -ExpandProperty Name

• Edited by mukesh-kumar 14 hours 41 minutes ago

function Test-Call{
    Param(
        [Parameter(Mandatory=$true,
            ValueFromPipeline=$true,
            ValueFromPipelineByPropertyName=$true,
            Position=0
         )]
        [ValidateNotNullOrEmpty()]
	[Alias('ComputerName','IPAddress','CN')]
        [string[]]$Name
    )
    Process{
       $name
    }
}

get-adcomputer -Filter * | Test-Call

Like this:

Indeed jrv that works but also means my property is now named Name rather than ComputerName.

I was under the impression that because I had alias of Name it would take this down the pipeline and apply it to ComputerName. Is this not correct?

Also "Select -ExpandProperty Name" works.

• Edited by AJPalmer 14 hours 44 minutes ago

Indeed jrv that works but also means my property is now named Name rather than ComputerName.

I was under the impression that because I had alias of Name it would take this down the pipeline and apply it to ComputerName. Is this not correct?

Also "Select -ExpandProperty Name" works.

• Edited by AJPalmer 14 hours 36 minutes ago

Expand property works because it fulfills the position=0 criteria.

Try this:
Get-Process |select -expand handles | Test-Call

To get multiple pipeline names you will need to sue parameter sets.

Yes that works.

Is there nothing I can do to get it to accept the Name property as the ComputerName property in the function without having to do the select-object?

I understand that PowerShell will match the two properties if they share the same 'Name' but I would sooner keep my script to use the property ComputerName.

Can you please pipe the Name property to Out-String before calling the function.

Something like this

  function test-call
	 {
	 	param(
					 [Parameter(Mandatory=$true,
				                   ValueFromPipeline=$true,
				                   ValueFromPipelineByPropertyName=$true,
				                   Position=0)]
				        [ValidateNotNull()]
				        [ValidateNotNullOrEmpty()]
				        [Alias('HostName','Server','IPAddress','CN','Name')]
				        [String[]]$ComputerName
	   )
	$ComputerName
	}
	
Get-Content "C:\servers.txt"| out-String |test-call 

 In my case C:\servers.txt has computers list. In your case it would be

Get-ADComputer -Filter * | Select -ExpandProperty Name | Out-String | Test-Call

• Edited by mukesh-kumar 13 hours 35 minutes ago

Can you please pipe the Name property to Out-String before calling the function.

Something like this

  function test-call
	 {
	 	param(
					 [Parameter(Mandatory=$true,
				                   ValueFromPipeline=$true,
				                   ValueFromPipelineByPropertyName=$true,
				                   Position=0)]
				        [ValidateNotNull()]
				        [ValidateNotNullOrEmpty()]
				        [Alias('HostName','Server','IPAddress','CN','Name')]
				        [String[]]$ComputerName
	   )
	$ComputerName
	}
	
Get-Content "C:\servers.txt"| out-String |test-call 

 In my case C:\servers.txt has computers list. In your case it would be

Get-ADComputer -Filter * | Select -ExpandProperty Name | Out-String | Test-Call

• Edited by mukesh-kumar 13 hours 27 minutes ago

Yes that works.

Is there nothing I can do to get it to accept the Name property as the ComputerName property in the function without having to do the select-object?

I understand that PowerShell will match the two properties if they share the same 'Name' but I would sooner keep my script to use the property ComputerName.

I repeat:

To get multiple pipeline names you will need to sue parameter sets.

Since you have made the parameter mandatory, i believe there is no need to use either [ValidateNotNull()] or [ValidateNotNullOrEmpty()] attributes.

        [Parameter(Mandatory=$true,
                   ValueFromPipeline=$true,
                   ValueFromPipelineByPropertyName=$true,
                   Position=0)]
        [Alias('HostName','Server','IPAddress','CN','Name')]
        [string[]]$ComputerName

Also, please make sure the property name from Get-ADComputer is nither Null or empty.

• Edited by mukesh-kumar Thursday, July 09, 2015 3:51 PM

did you expanded the property ? 

Get-ADComputer -Filter * | Select-Object -ExpandProperty Name

• Edited by mukesh-kumar Thursday, July 09, 2015 4:19 PM

Indeed jrv that works but also means my property is now named Name rather than ComputerName.

I was under the impression that because I had alias of Name it would take this down the pipeline and apply it to ComputerName. Is this not correct?

Also "Select -ExpandProperty Name" works.

• Edited by AJPalmer Thursday, July 09, 2015 4:24 PM

Can you please pipe the Name property to Out-String before calling the function.

Something like this

  function test-call
	 {
	 	param(
					 [Parameter(Mandatory=$true,
				                   ValueFromPipeline=$true,
				                   ValueFromPipelineByPropertyName=$true,
				                   Position=0)]
				        [ValidateNotNull()]
				        [ValidateNotNullOrEmpty()]
				        [Alias('HostName','Server','IPAddress','CN','Name')]
				        [String[]]$ComputerName
	   )
	$ComputerName
	}
	
Get-Content "C:\servers.txt"| out-String |test-call 

 In my case C:\servers.txt has computers list. In your case it would be

Get-ADComputer -Filter * | Select -ExpandProperty Name | Out-String | Test-Call

• Edited by mukesh-kumar Thursday, July 09, 2015 5:33 PM

Hi AJ,

the only way I was able to make it work (short of writing a .NET Parameter Class) is moving the type validation from the parameter binding into the function process:

function Test-Call
{
	[CmdletBinding()]
	param (
		[Parameter(Mandatory = $true,
				   ValueFromPipeline = $true,
				   Position = 0)]
		[ValidateNotNull()]
		[ValidateNotNullOrEmpty()]
		[Alias('HostName', 'Server', 'IPAddress', 'CN', 'Name')]
		[object]
		$ComputerName
	)
	
	Begin
	{
		function Process-Data
		{
			Param (
				$Name
			)
			
			Write-Host $Name
		}
	}
	Process
	{
		foreach ($Computer in $ComputerName)
		{
			switch ($Computer.GetType().FullName)
			{
				"System.String" { Process-Data $Computer }
				"Microsoft.ActiveDirectory.Management.ADComputer" { Process-Data $Computer.Name }
				default { throw "Invalid Input type!"}
			}
			
		}
	}
}

Cheers,
Fred