class Controller_Common extends Controller_Template {
   public $template = 'admin/admin_template.tpl';

       {include 'admin/header.tpl' base_url=$base_url ... list of variables  } 

      <div class="content">{$content}</div>

      <div class="clearing"></div>
        {include 'admin/footer.tpl' base_url=$base_url ... list of variables  }

  $breadcrumbs_links= Breadcrumbs::instance()->generate( $this->breadcrumb ) ;
  ...
  $data = array( ... 'breadcrumbs_links'=>$breadcrumbs_links );

  $this->template->content = View::factory( 'admin/operator_edit.tpl', $data );