Merging Final Renderings back down into Shared Renderings

Merge-Layout.ps1

function Merge-Layout {
	[CmdletBinding()]
	param(
		[Parameter(Mandatory = $true,Position = 0,ValueFromPipeline = $true)]
		[item]$Item
	)

	process {
		$layoutField = New-Object "Sitecore.Data.Fields.LayoutField" -ArgumentList ($Item.Fields[[Sitecore.FieldIDs]::LayoutField]);
		$finalLayoutField = New-Object -TypeName "Sitecore.Data.Fields.LayoutField" -ArgumentList $Item.Fields[[Sitecore.FieldIDs]::FinalLayoutField]

		if ($layoutField -eq $null) {
			Write-Error "Couldn't find layout on: $($Item.Name)"
		}

		if ($finalLayoutField -eq $null) {
			Write-Error "Couldn't find final layout on: $($Item.Name)"
		}

		if ($finalLayoutField.Value -eq $null -or $finalLayoutField.Value -eq "") {
			return;
		}

		$finalLayoutDefinition = [Sitecore.Layouts.LayoutDefinition]::Parse($finalLayoutField.Value)

		$Item."__Renderings" = $finalLayoutDefinition.ToXml();
		Reset-ItemField -Item $Item -Name "__Final Renderings" -IncludeStandardFields
	}
}