PowerShell cmdlet to provision Nintex Workflow Constants

If you are building Nintex Workflows, and especially if you are deploying them across multiple environments, then you should be considering using Nintex Workflow constants. These constants are remarkably useful to make your Nintex Workflows portable, so that they can easily be deployed into multiple environments without confusion or wasted effort. Any workflow parameters which are specific to the environment in which the workflow is running, or which are likely to be changed by the business at some stage, should be built into your workflows using these constants.

Many of our clients are looking to improve their processes for deploying and managing SharePoint and Nintex based functionality, and the critical aspects tend to fall around governance and repeatability. So in the interests of repeatability, here's a PowerShell cmdlet to create a new Nintex Workflow constant.

With this script you can specify any type of constant, including credentials which are useful for service accounts. You can also define the constant at a scope of Farm, Site Collection or Site.

The cmdlet needs to be run on a server within the SharePoint farm where the constant is to be created. If anyone is aware of alternate methods that can be run remotely, please let me know in the comments!

You can view and download the cmdlet here. Note that the file has been renamed with a .ps1.txt file extension as some data transfer mechanisms block .ps1 files as a security concern - so you'll need to rename the file to have a .ps1 extension after you download it.

<#
.SYNOPSIS
   Creates a Nintex Workflow Constant
.DESCRIPTION
   
.PARAMETER <Name>
   Mandatory - the Name of the Constant. Keep these unique!
.PARAMETER <Description>
   Mandatory - the Description of the Constant. Use this to help other developers understand what it's used for.
.PARAMETER <Type>
   Mandatory - the Type of the Constant. Must be one of: Number, String, Date, SecureString, Credential
.PARAMETER <Scope>
   Mandatory - where the Constant is defined. Must be one of: Farm, SiteCollection, Web
.PARAMETER <Value>
   Optional - the value of the Constant. This isn't used for Credential type constants, but it's Mandatory for every other type.
.PARAMETER <Url>
   Optional - but Mandatory is the Scope is SiteCollection or Web. Defines where the Constant should live.
.PARAMETER <Sensitive>
   Optional - default value is $false.
.PARAMETER <AdminOnly>
   Optional - default value is $false.
.PARAMETER <Username>
   Optional - but Mandatory if Type is Credential.
.PARAMETER <Password>
   Optional - but Mandatory if Type is Credential.
.EXAMPLE
   #Here's an example that generates a Sensitive, Credential type constant at Web level:
   .\Create-NintexWFConstant.ps1 `
  -Name "test" `
  -Description "Example only" `
  -Scope "Web" `
  -Type "Credential" `
  -Sensitive $true `
  -Username "DOMAIN\user" `
  -Password "password123" `
  -Url "http://myfarm/sites/myweb"

 #Here's a second example that creates a Farm string type Constant:
 .\Create-NintexWFConstant.ps1 `
  -Name "test2" `
  -Description "Example only" `
  -Scope "Farm" `
  -Type "String" `
  -Value "example constant value"
#>

Param(
 [Parameter(Mandatory = $true, Position = 1)]
 [string] $Name,
 [Parameter(Mandatory = $true, Position = 2)]
 [string] $Description,
 [Parameter(Mandatory = $true, Position = 3)]
 [string] $Type,
 [Parameter(Mandatory = $true, Position = 4)]
 [string] $Scope,
 [Parameter(Mandatory = $true, Position = 5)]
 [string] $Value,
 [Parameter(Mandatory = $false, Position = 6)]
 [string] $Url,
 [Parameter(Mandatory = $false, Position = 7)]
 [bool] $Sensitive = $false,
 [Parameter(Mandatory = $false, Position = 8)]
 [bool] $AdminOnly = $false,
 [Parameter(Mandatory = $false, Position = 9)]
 [string] $Username = "",
 [Parameter(Mandatory = $false, Position = 10)]
 [string] $Password = ""
)

[System.Reflection.Assembly]::LoadWithPartialName('Nintex.Workflow') | Out-Null

$ArgsValid = $true

if ($Type -ne "Number" -and $Type -ne "String" -and $Type -ne "Date" -and $Type -ne "SecureString" -and $Type-ne "Credential")
{
 Write-Host "Error - Type parameter must be one of: Number, String, Date, SecureString, Credential." -ForegroundColor Red
 $ArgsValid = $false
}

if ($Type -eq "Credential")
{
 if ($Username -eq $null -or $Username -eq "" -or $Password -eq $null -or $Password -eq "")
 {
  Write-Host "Credential Error - Username and Password combination not supplied." -ForegroundColor Red
  $ArgsValid = $false
 }

 # Generate string for Credential
 $cred = New-Object Nintex.Workflow.CredentialValue($Username, $Password)
 $serialiser = New-Object System.Xml.Serialization.XmlSerializer($cred.GetType())
 $sb = New-Object System.Text.StringBuilder
 $sw = New-Object System.IO.StringWriter($sb)
 $serialiser.Serialize($sw, $cred)
 $Value = $sb.ToString()

}
else
{
 if ($Value -eq $null -or $Value -eq "")
 {
  Write-Host "Error - Value must be supplied for Constants of Type other than Credential." -ForegroundColor Red
  $ArgsValid = $false
 }
}

$SiteId = [Guid]::Empty
$WebId = [Guid]::Empty

if ($Scope -eq "Farm")
{
 #Use default SiteId and WebId values
}
else
{
 if ($Scope -eq "SiteCollection")
 {
  $SiteId = (Get-SPSite $Url).Id
 }
 else
 {
  if ($Scope -eq "Web")
  {
   $Web = Get-SPWeb $Url
   $WebId = $Web.Id
   $SiteId = $Web.Site.Id
  }
  else
  {
   Write-Host "Error - Scope parameter not valid: must be one of Farm, SiteCollection, Web." -ForegroundColor Red
   $ArgsValid = $false
  }
 }
}


if ($ArgsValid)
{
 Write-Host ("Attempting to create Workflow Constant " + $Name + " ... ") -NoNewline 

 $constant = New-Object Nintex.Workflow.WorkflowConstant(`
  $Name, $Description, $Value, $Sensitive, $SiteId, $WebId, $Type, $AdminOnly)

 $constant.Update()

 Write-Host "done"
}