class Admin::PagesController

def render_preview
  params.permit!
  Page.transaction do
    page_class = Page.descendants.include?(model_class) ? model_class : Page
    if request.referer =~ %r{/admin/pages/(\d+)/edit}
      page = Page.find($1).becomes(page_class)
      layout_id = page.layout_id
      page.update_attributes(params[:page])
      page.published_at ||= Time.now
    else
      page = page_class.new(params[:page])
      page.published_at = page.updated_at = page.created_at = Time.now
      page.parent = Page.find($1) if request.referer =~ %r{/admin/pages/(\d+)/children/new}
    end
    page.pagination_parameters = pagination_parameters
    process_with_exception(page)
  end
end