Delete a theme from the theme gallery with PowerShell

Question

I've found that import-spweb duplicates items in the theme gallery. Using export-spweb and then import-spweb, the target site is doubled up on each of the themes in the theme gallery. Everytime I do another import-spweb on this site collection, even after deleting the site collection and creating a blank one with no template, it adds another copy of each theme to the theme gallery.

So I'd like to write a little PowerShell script that will find duplicates and delete them, but I'm not sure what files I should be deleting. I looked in the "Theme Gallery" list on the SPWeb I've created, but it's items are the actual theme files.

get-spsite | %{
    $_.allwebs | %{
        $theme_gallery = $_.lists|?{$_.title -eq "Theme Gallery"}
        $theme_gallery.items|select name
    }
}

output:

How can a Theme be removed from the gallery for a site with PowerShell?

Answer 1

The below code will delete the mentioned theme from the web. You can modify it to loop through to find the duplicates and delete theme.

$site=Get-SPSite "http://servername/sites/sitename"
$web=$site.RootWeb
if ($web.GetFile("_catalogs/theme/YourCustomTheme.thmx").Exists -eq $true)
{
   $file = $web.GetFile("_catalogs/theme/YourCustomTheme.thmx")
   $file.Delete(); 
}
else
{
   write-host -f yellow "File is not in the Theme Gallery"
} 

Note:

To find the exact name and path of the theme, follow below steps,

1. Open SharePoint Designer -> open site.
2. Click All files -> _catalogs -> theme -> This will list all the installed themes.

Hope this will help you :)