Standard\Controllers\UsersController::upsertGroupProcessAction PHP Method

    public function upsertGroupProcessAction()
    {
        $id = $_POST['id'] ?? null;
        if ($id && !ctype_digit($id)) {
            $this->flasher->error('E01 Invalid group ID: ' . $id);
            $this->redirect('/users/groups');
        }
        $group = null;
        if ($id) {
            $group = Gatekeeper::findGroupById($id);
            if (!$group) {
                $this->flasher->error('E02 Invalid group ID: ' . $id);
            }
        }
        try {
            v::alnum('-._')->setName('Group name')->check($_POST['name']);
        } catch (ValidationException $e) {
            $this->flasher->error($e->getMainMessage());
            echo $this->twig->render('users/groups/upsert.twig', ['flashes' => $this->flasher->display(), 'group' => $group ?: $_POST]);
            return false;
        }
        if ($group) {
            $group->name = $_POST['name'];
            $group->description = $_POST['description'];
            $group->save();
        } else {
            Gatekeeper::createGroup($_POST);
            if (Gatekeeper::getLastError()) {
                $this->flasher->error($this->site['debug'] ? Gatekeeper::getLastError() : "Could not create group!");
                echo $this->twig->render('users/groups/upsert.twig', ['flashes' => $this->flasher->display(), 'user' => $group ?: $_POST]);
                return false;
            }
            $this->flasher->success('Successfully created group.');
            $this->redirect('/users/groups');
        }
    }