class DeleteItemsProcess extends Nette\Object
{
    private $model;

    public function __construct(Nette\Http\User $user, ItemsModel $model)
    {
        if(!$user->isInRole('administrator')) {
            throw new Nette\InvalidStateException("User is not allowed to delete items");
        }

        $this->model = $model;
    }

    public function run($itemId)
    {
        $item = $this->model->getItem($itemId);
        $item->delete();

        $contents = $this->model->findAllContents(NULL, array('item_id' => $itemId));
        foreach ($contents as $content){
            $content->delete();
        }
    }
}


// signal


public function handleDelete($id)
{
    try {
        $process = new DeleteItemsProcess($this->getUser(), $this->model);
        $process->run($id);
        $this->flashMessage('Item has been deleted');

    } catch (Nette\InvalidStateException $e) { }

    $this->redirect('this');
}