class Middleman::Extensions::DirectoryIndexes

def manipulate_resource_list(resources)
  index_file = app.config[:index_file]
  new_index_path = "/#{index_file}"
  extensions = %w(.htm .html .php .xhtml)
  resources.each do |resource|
    # Check if it would be pointless to reroute
    next if resource.destination_path == index_file ||
            resource.destination_path.end_with?(new_index_path) ||
            !extensions.include?(resource.ext)
    # Check if file metadata (options set by "page" in config.rb or frontmatter) turns directory_index off
    next if resource.options[:directory_index] == false
    extensions.each do |ext|
      resource.destination_path = resource.destination_path.chomp(ext)
    end
    resource.destination_path += new_index_path
  end
end