isValidCategory example

$view->assign('sFormData', [
                    'sVoteMail' => $userData['additional']['user']['email'],
                    'sVoteName' => $userData['billingaddress']['firstname'] . ' ' . $userData['billingaddress']['lastname'],
                ]);
            }
        }

        $number = $this->Request()->getParam('number');
        $selection = $this->Request()->getParam('group', []);

        $categoryId = (int) $this->Request()->get('sCategory');
        if (!$this->isValidCategory($categoryId)) {
            $categoryId = 0;
        }

        try {
            $product = $this->container->get('modules')->Articles()->sGetArticleById(
                $id,
                $categoryId,
                $number,
                $selection
            );
        } catch (Exception $e) {