unique slugs with multi entities in symfony2 - symfony

Question

I have a small symfony2 application where a user can create pages. Each page should be accessible via the route /{user_slug}/{page_slug}. I have the entities user and page and I use the sluggable behavior for both entities. In order to find the correct page the combination of user_slug and page_slug has to be unique.
What is the best way to check that the combination of user_slug and page_slug is uniqe?

Answer 1

Try this in your prepository:
public function findByUsernameAndSlug($username, $slug)
{
$em = $this->getEntityManager();
$query = $em->createQuery("
SELECT g
FROM Acme\PagesBundle\Entity\Page p
JOIN p.owner u
WHERE u.username = :username
AND p.slug = :slug
")
->setParameter('username', $username)
->setParameter('slug', $slug);
foreach ($query->getResult() as $goal) {
return $goal;
}
return null;
}

Answer 2

Before you persist the entity in your service-layer check whether given combination of user and page slug are unique, if not modify the page slug (append -2 or something like that) or throw an exception:
public function persistPage(Page $page) {
$userSlug = $page->getUser()->getSlug();
$pageSlug = $page->getSlug();
if ($this->pagesRepository->findOneBySlugs($userSlug, $pageSlug) != null) {
// given combination already exists
throw new NonUniqueNameException(..);
// or modify the slug
$page->setSlug($page->getSlug() . '-2');
return $this->persistPage($page);
}
return $this->em->persist($page);
}
// PagesRepository::findOneBySlugs($userSlug, $pageSlug)
public function findOneBySlugs($userSlug, $pageSlug) {
$query = $this->em->createQueryBuilder('p')
->addSelect('u')
->join('p.user', 'u')
->where('p.slug = :pageSlug')
->where('u.slug = :userSlug;)
->getQuery();
$query->setParameters(combine('userSlug', 'pageSlug'));
return $query->getSingleResult();
}