SharePoint Powershell -- Awesomesauce

Introduced with SharePoint 2010 (but actually possible with older versions) we were given direct access to the SharePoint object model in a interpreted scripting environment.

With a simple script like this, I can list all of the lists and libraries in a SharePoint web application:

$wa = get-spwebapplication http://site.domain.com
foreach($site in $wa.Sites) {
    foreach($web in $site.AllWebs) {
        foreach($list in $web.Lists) {
            write-host $wa.Name $web.Title $web.Url $list.Title
        }
    }
}

Great, so what you can list a bunch of the content.  Tell me something I can't do with other tools...

OK, here's one.  I had a WSP that installed custom page layouts.  One of the page layouts got modified by a user using SharePoint designer, and even if I returned the page layout to the original state, upgrading or re-installing the WSP wouldn't overwrite the page layout in the content database.

Solution: Detach the each of the publishing pages from the page layout and  make a file that lists each of the publishing pages that were attached to the page layout.  Then remove all of the bad stuff using what ever tool you like and reattach the page layouts based on the data we saved in the file.

Check out this script, the first half of the process of detaching the page layouts. $detLog gets set outside the function and is the full page to the change log.  Just point the function at an SPWeb and a reference to new page layout (it needs to be a Microsoft.SharePoint.Publishing.PageLayout) and away it goes, cycling through the entire SPWeb and its children.  Oh, $comment gets set outside the function too.  It could be something snappy like "Detaching Page Layout for Upgrade."

 Function BFS-PubPage($web, $newlayout) {
    $web.Lists | foreach-object -process {
        $l = $_
        $l.Items | foreach-object -process {
            $i = $_
            if ([Microsoft.SharePoint.Publishing.PublishingPage]::IsPublishingPage($i)) {
                $pp = [Microsoft.SharePoint.Publishing.PublishingPage]::GetPublishingPage($i)
                if ($pp.Layout -ne $null) {
                
                    if ($pp.Layout.ServerRelativeUrl -eq "/_catalogs/masterpage/OffendingLayout1.aspx" `
                       -or $pp.Layout.ServerRelativeUrl -eq "/_catalogs/masterpage/OffendingLayout2.aspx") {
                        write-host -ForegroundColor DarkBlue ($web.Url + "/" + $pp.Url)
                        
                        $cl = $pp.Layout
                        
                        $pp.CheckOut()
                        $pp.Layout = $newlayout
                        $pp.Update()
                        $pp.CheckIn($comment)
                        $pf = $pp.ListItem.File
                        $pf.Publish($comment)
                        $pf.Approve($comment)
                        
                        add-content $detLog ($web.Url + "`t" + $i.Name + "`t" + $pp.Url + "`t" + $cl.ServerRelativeUrl)
                    }
                     else {
                        write-host -ForeGroundColor DarkYellow `
                             ($web.Url + "/" + $pp.Url +"`t" + $pp.Layout.ServerRelativeUrl)
                    }
                }
            }
            
        }
    }
    
    $web.Webs | foreach-object -process {
        if ($_ -ne $null) {
            BFS-PubPage $_ $newlayout
        }
    }
}

You probably noticed, but this script uses a different way to implement the for-each loops.  Instead of using the C# style of the loop, it uses the object pipe method.  I'm guessing one method is probably more efficient than the other, but  you never know.