LoadModuleConfig PowerShell Module

Overview

Provides simple control for saving and loading configuration files for Powershell modules using CliXml. Distribute your module with this script and it will generate an xml based configuration file in the user's local AppData directory in a WindowsPowerShell\Modules$ModuleName$ModuleName.config.xml file and will store and populate the configuration data in a Global:[hash] variable with the name $($ModuleName)Settings.

This is a fairly automated config generator, loader, and exporter that invokes during module import. Unlike the PrivateData field in a module manifest file which is tied to the module itself, this solution was created for storing both user and project settings that would not likely change with a versions of the module itself. Perhaps values that would be tedious to pass to functions again and again.

Instead of doing xml creation and parsing manually it uses PS built-in CliXml.

Reasoning

Looking around the internet it is easy to find multiple methods of loading and using configuration data for scripts, not as easy to find examples for PowerShell scripts, and even rarer sill for modules. Yet, in each that was found it seemed that something was missing. Using a plain text file to store key/value pairs isn't very PowerShelly, and using an xml file where you need to create the xml and create the writer/loader wasn't a good option either.

Usage

---

###Setup:

• Use New-ModuleManifest to create a manifest named the with the same name as the manifest you are loading data for but with an extension of 'config.psd1'

• Enter LoadModuleConfig.ps1 in the NestedModules field.

#####This is what starts the loader. (As seen in the FuncGuard module):

# Modules to import as nested modules of the module specified in ModuleToProcess
NestedModules = @('FuncGuard.config.psd1')

• Open the new manifest in an editor and change the PrivateData field to include hashes for LocalUser and Settings. After the Settings key add any values that you want to include with your module. This data will be your module's default config data.

#####Here is an example PrivateData field (as used in the FuncGuard module):

# Private data to pass to the module specified in ModuleToProcess
PrivateData = @{
	"LocalUser" = @{
		"Settings"=@{
			"ActiveConfiguration" = "PSUnit"
			"Configurations"=@{
				"PSUnit" =@{
					"Name"="PSUnit";
					"Path"=$(join-path -Path $Env:Temp -ChildPath "FuncGuard.PSUnit");
					"Prefix"="PSUNIT"
				}
			}
		}
	}
}

• After loading the module a global variable will be available with a name of $($ModuleName)Settings and the values from the Settings section of the PrivateData can be accessed using normal hash retrieval.

###Using the settings hash (as used in the FuncGuard module):

$config = $FuncGuardSettings["Configurations"].$($FuncGuardSettings["ActiveConfiguration"])
$Path = $config.Path

• To save settings that have been modified simply call the export() method.

###Modifying and saving a setting (as used in the FuncGuard module):

	if ( $FuncGuardSettings.("Configurations").containskey($Name) -eq $false ) {
		$Configuration=@{"Name" = $Name; "Path" = $Path; "Prefix" = $Prefix; "Type" = "Custom"}
		$FuncGuardSettings.("Configurations").add($Name, $Configuration)
		$FuncGuardSettings.export()
	}

Parameter validation and default value setting.

The FuncGuard module manages various projects, where one is set to 'active', yet the active value is just a provider for default param values.

[Parameter(ParameterSetName="Validate", Mandatory=$true, Position=1,
	HelpMessage="`nName used to identify the project within the configuration settings.")]
[Parameter(ParameterSetName="Force", Position=0, Mandatory=$true,
	HelpMessage="`nName used to identify the project within the configuration settings.")]
[ValidateScript({
	($FuncGuardSettings.("Configurations").containskey("$_") -eq $false) -or
	($Force)
})]
[string]
$Name = $(Throw 'A unique project name is required.')

8< --- clipped 8< ---

[Parameter(
	HelpMessage="`nPrefix used in the C++ Preprocessor MACRO.")]
[ValidateScript({testPrefixParam $_})]
[string]
$Prefix = $(Get-FuncGuardProjectPrefix)

8< --- clipped 8< ---

function Get-FuncGuardProjectPrefix {
	return 	$FuncGuardSettings.("Configurations").(
		$($FuncGuardSettings.("ActiveConfiguration"))).Prefix
}