handles swapping out templated values in configs from nested prop files

ConfigTemplateSwitcher.ps1

#config swapper
#load the default values in to a hash
#get the values from the env and override in the hash
#foreach key in the hash replace the {[key]} with the value i.e. (Get-Content $_) -replace "$tokenedKey","$value" | Set-Content -path $_.$env 
function Create-ConfigFromTemplate{
		 param ([string]$envPropFile, #".\$env.properties"
		 		[string]$outputFolder,#".\$env\
		 		[string]$templateFile #".\App.template.config" 
		 ) 
	
	$outputFile = Join-Path $outputFolder (split-path ($templateFile.Replace(".template", "")) -leaf)
		
	if((Test-Path $outputFolder) -eq $false) { 
		$newDir = New-Item $outputFolder -type directory 
		Write-Host "new directory created for output - " $newDir.FullName
	}

	$hash = @{}
	
	$envXmlData = [xml](Get-Content $envPropFile)
	$basePropFile = $envXmlData.Configuration.GetAttribute("Inherits")
	if($basePropFile){
		$baseXmlData = [xml](Get-Content (join-path `
			(Split-Path $envPropFile -Parent) $basePropFile))
		#Put the base values in a hashtable
		$baseXmlData.Configuration.Properties.Property | 
		%{
			$hash[$_.Key] = $_.Value
		}
	}
	#Add or override the more specific values from the environment config
	$envXmlData.Configuration.Properties.Property | 
		%{
			$hash[$_.Key] = $_.Value
		}	
	#create the ouput file ready to have the tokens swapped out
	Copy-Item $templateFile $outputFile; 
	$hash.GetEnumerator() |
		%{
			$key = $_.Key
			$value = $_.Value
			$tokenedKey = "\`$\{$key\}" #powershell escape is ` regex escape is \
			#continuously replace the values and rewrite to the ouput file - this is standrd replace technique in PS
			(Get-Content $outputFile) -replace "$tokenedKey" , "$value" | 
				Set-Content -path $outputFile
		}
	#Check for any missed tokens
	$missedtokens = Select-String -Pattern \$\`{ -path $outputFile
	if($missedtokens -ne $null)
	{
		Write-Warning "There are tokens that have not been swapped out:"
		$missedtokens | %{
			Write-Warning $_
		}
	}
}

function Create-AllConfigFromTemplateFolder
{
		param (	[string]$configPath, #"C:\Configurations"
		 	[string]$templateFile,#"C:\projectA\App.template.config"
		 	[string]$ouputRootLocation #"."
		) 
	Get-ChildItem -Path $configPath  -Filter *.properties | 
	%{	$_.BaseName } | 
	%{
		$propFile = join-path $configPath "$_.properties"
		Create-ConfigFromTemplate -envPropFile $propFile `
                                -outputFolder "$ouputRootLocation\$_\" `
                                -templateFile $templateFile `
	}
}
########### example files #####
##App.template.config
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
   <appSettings>
    <add key="Abc" value="${abc}"/>
    <add key="def" value="${def}"/>
    <add key="def" value="${ghi}"/>
  </appSettings>
</configuration>
#dev.prop
<?xml version="1.0" encoding="utf-16"?>
<Configuration xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  Inherits=".\base.prop">
  <Properties>
    <Property>
      <Key>abc</Key>
      <Value>My overriding value</Value>      
    </Property>
    <Property>
      <Key>def</Key>
      <Value>another overriding value</Value>      
    </Property>    
  </Properties>
</Configuration>
#base.prop
<?xml version="1.0" encoding="utf-16"?>
<Configuration xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  Inherits=".\base.prop">
  <Properties>
    <Property>
      <Key>abc</Key>
      <Value>My base value</Value>      
    </Property>
    <Property>
      <Key>def</Key>
      <Value>another base value</Value>      
    </Property>
    <Property>
      <Key>ghi</Key>
      <Value>base value that is not overriden</Value>      
    </Property>    
  </Properties>
</Configuration>

some white spacing issues may arise from entering this in via the web interface