Breve esempio (preso dal link che hai postato, il file del modulo):
public function displayForm()
{
$this->context->smarty->assign('request_uri', Tools::safeOutput($_SERVER['REQUEST_URI']));
$this->context->smarty->assign('path', $this->_path);
$this->context->smarty->assign('EXAMPLE_CONF', pSQL(Tools::getValue('EXAMPLE_CONF', Configuration::get('EXAMPLE_CONF'))));
$this->context->smarty->assign('submitName', 'submit'.Tools::ucfirst($this->name));
$this->context->smarty->assign('errors', $this->errors);
// You can return html, but I prefer this new version: use smarty in admin,
return $this->display(__FILE__, 'views/templates/admin/configure.tpl');
}
$this->context->smarty->assign() ti consente di aggiungere variabili per il template, mentre il metodo display visualizza il file del template