Vista - CTP: Script cmdlet parameter attributes error

This is a sample v2 script cmdlet that takes a string array for the "Name"
parameter.


Cmdlet Test-Param{

param(
[Mandatory]
[Position(0)]
[ValidateNotNullOrEmpty]
[ValueFromPipeline]
[string[]]$Name
)

process{
$Name | foreach { write-output $_ }
}


}


All is fine when I run:

Test-Param -name "shay","levi"

PS > shay
PS > levi


I get an error when I try to pipe the strings:

"shay","levi" | Test-Param


PS > shay
Attribute cannot be added because it would cause the variable Name with value
to become invalid.
+ <<<< "shay","levi" | Test-Param


When I remove the [ValidateNotNullOrEmpty] attribute, it works fine:

PS > shay
PS > levi



What am I doing wrong?


-----
Shay Levi
$cript Fanatic
http://scriptolog.blogspot.com
Hebrew weblog: http://blogs.microsoft.co.il/blogs/scriptfanatic

Giving it a default value seems to remove the error eg......

Cmdlet Test-Param{

param(
[Mandatory]
[Position(0)]
[ValidateNotNullOrEmpty]
[ValueFromPipeline]
[string[]]$Name="whatever"
)

process{
$Name | foreach { write-output $_ }
}


}


--
Jon


"Shay Levi" <no@xxxxxx> wrote in message
news:8766a94412b9b8ca0a25978bc204@xxxxxx

Try this also:

$strArray1 = 'one is element [0]','two is element [1]'
$strArray2 = 'three is element [0]','four is element [1]'

# unless you pipe a single element
'one is one' | test-param

# ...use the comma operator to ensure passing an Array
, $strArray1 | test-param
, ('one is element [0]','two is element [1]') | test-param
, [string[]]('one is element [0]','two is element [1]') | test-param

# array of arrays
, (('one is element [0][0]','two is element [0][1]'),
('three is element [1][0]','four is element [1][1]')) | test-param

# if not, only the first element is piped and of course that errors
$strArray1 | test-param

--
Kiron

Thanks Kiron & Jon.

What If I pipe a file content:

PS > get-content names.txt | test-param

This gives the same error and I don't want to use a default value for the
name parameter.
A workaround is to omit the ValidateNotNullOrEmpty attribute but I wonder
why, in this case, both ValidateNotNullOrEmpty
and ValueFromPipeline can't live together.



-----
Shay Levi
$cript Fanatic
http://scriptolog.blogspot.com
Hebrew weblog: http://blogs.microsoft.co.il/blogs/scriptfanatic


PS>> shay
PS>> leviPS>> shay
PS>>PS>> shay
PS>> levi

The way I understand it, the 'mandatory' attribute already implies that it
can't be null, an empty string, or an empty array. So the additional
'ValidateNotNullOrEmpty' is redundant, since it's been previously implied.
You'd only use this attribute when you haven't specified Mandatory. You can
see that with the various errors here (remove the Mandatory and there would
be no errors) .....


#----------------------------------------------
Cmdlet Test-Param{

param(
[Mandatory]
[Position(0)]
[ValueFromPipeline]
[string[]]
$Name
)

process{
$Name | foreach { write-output $_ }
}

}

,@() | Test-Param
"jon","" | Test-Param
"jon", $null | Test-Param
"jon1", "jon2" | Test-Param

#-----------------------------------------------------------




--
Jon


"Shay Levi" <no@xxxxxx> wrote in message
news:8766a94412c9f8ca0a442f55e22c@xxxxxx

In that case you can:

, (get-content data.csv) | test-param

# ...or pipe each line to Test-Param
# but I don't think that's what you're after
get-content data.csv | % {$_ | Test-Param}

The problem is that when assigning by Pipeline Value, only the first element is assigned to $Name, unless you specifically pipe it as an array or just pipe one element instead.
Jon makes a good point. I used the functions below to list parameters with certain attributes and found none that had both [Mandatory] and [ValidateNotNullOrEmpty] and accepts [String[]] as Input, so like you say they can't live together

# These functions may not work in v1, not sure

function List-ParamsA {
# List-ParamsA lists parameter with the following attributes:
# [Mandatory][ValueFromPipeline][String[]]
# found 27
get-command * -type Cmdlet | % {
$Cmdlet = $_.Name
$_.ParameterSets | % {
$_.Parameters | ? {
$_.IsMandatory -and
$_.ValueFromPipeline -and
$_.ParameterType -match 'string\[]'
} | % {
"Cmdlet $Cmdlet > Parameter $($_.name)"
}
}
} | sort -unique
}

function List-ParamsB {
# List-ParamsB lists parameter with the following attributes:
# [ValueFromPipeline][ValidateNotNullOrEmpty][String[]]
# found 103
get-command * -type Cmdlet | % {
$Cmdlet = $_.Name
$_.ParameterSets | % {
$_.Parameters | ? {
$_.ValueFromPipeline -and
$_.ParameterType -match 'string\[]'
$_.Attributes -match 'ValidateNotNullOrEmpty'
} | % {
"Cmdlet $Cmdlet > Parameter $($_.name)"
}
}
} | sort -unique
}

function List-ParamsC {
# List-ParamsC lists parameter with the following attributes:
# [Mandatory][ValueFromPipeline][ValidateNotNullOrEmpty][String[]]
# found 0
get-command * -type Cmdlet | % {
$Cmdlet = $_.Name
$_.ParameterSets | % {
$_.Parameters | ? {
$_.IsMandatory -and
$_.ValueFromPipeline -and
$_.ParameterType -match 'string\[]' -and
$_.Attributes -match 'ValidateNotNullOrEmpty'
} | % {
"Cmdlet $Cmdlet > Parameter $($_.name)"
}
}
} | sort -unique
}

--
Kiron

Thanks again guys!

-----
Shay Levi
$cript Fanatic
http://scriptolog.blogspot.com
Hebrew weblog: http://blogs.microsoft.co.il/blogs/scriptfanatic


PS>> get-content names.txt | test-param
PS>>PS>>> shay
PS>>> leviPS>>> shay
PS>>>PS>>> shay
PS>>> levi