CODEWITHSUNDEEP
powershellpowershell-3.0powershell-4.0
Pradebban Raja
Pradebban Raja

Reputation: 463

Powershell: How to add null parameters in function call with Splatting

I have a function call implemented using Splatting.

$funtioncall= @{                                   
      Param1=$Param1;
      Param2=$Param2;
      Param3=$Param3;
      Param4=$Param4;
      Param5=$Param5;
}
function @functioncall

On a certain scenario i wish to add two more optional Parameters to the function call only if they are not null.

So i have $OptionalParam1 and $OptionalParam2

I currently have the below code to enable splatting as it will not allow nulls to be included in the Hash Table!

if(($OptionalParam1)-and($OptionalParam2))
{
   $funtioncall= @{                                   
          Param1=$Param1;
          Param2=$Param2;
          Param3=$Param3;
          Param4=$Param4;
          Param5=$Param5;
          OptionalParam1=$OptionalParam1;
          OptionalParam2=$OptionalParam2;
                   }
}
else
{
   $funtioncall= @{                                   
          Param1=$Param1;
          Param2=$Param2;
          Param3=$Param3;
          Param4=$Param4;
          Param5=$Param5;
                  }
}
function @functioncall

Is there a simpler way i can do this with Splatting?

This without splatting would be easier to implement and function call would look like below,( as i can have the parameter defined in the function to allow null )

function -Param1 $Param1 -Param2 $Param2 -Param3 $Param3 -Param4 $Param4 -Param5 $Param5 -OptionalParam1 $OptionalParam1 -OptionalParam2 $OptionalParam2

Upvotes: 0

Views: 777

Answers (2)

Jerome
Jerome

Reputation: 1

Took me forever to find this, so even though this is an old post I thought I would share the answer.

 $MyParameters= @{                                   
      Param1=$Param1
      Param2=$Param2
      Param3=$Param3
      Param4=$Param4
      Param5=$Param5
 }

 #If optional parameter data is supplied/exists, add it as a new hash item
 if ($null -ne $OptionalParam1Data) {
      $MyParameters.Add('OptionalParam1', $OptionalParam1Data)
 }

You can repeat adding things with IF to the set of parameters all day. If data exists then the parameter is added, if it doesn't then it's not. The only gotcha is still the null parameters. There has to be at least 1 real parameter from the get-go else the function can still complain, so you would need to catch that situation and handle it separately.

Example:     
Do-MyFunction @MyParameters

Upvotes: 0

Matt
Matt

Reputation: 46710

You should not have to change anything. $null is still a value so there is no reason to treat building of the variable $funtioncall differently at all

$param1 = "Awesome"
$OptionalParam1 = $null

$funtioncall= @{                                   
      Param1=$Param1;
      OptionalParam1=$OptionalParam1;
}

So now the hashtable contains a null for OptionalParam1

Name                           Value                                                                                                                
----                           -----                                                                                                                
OptionalParam1                                                                                                                                      
Param1                         Awesome

So as long as your function can handle to possibility of the param being null there will be no issue. I made a small function that displays those values.

This @funtioncall

Param1 is 'Awesome'
OptionalParam1 is ''

Upvotes: 2

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