Doctrine many to many: has user liked the article? - php

Question

I have 2 Entities
User
Article
and a “likedByUsers” Many To Many relationship between both.
When I show an article, I want to know if the user has liked it so a heart icon is shown.
I've got this in the ArticleRepository:
public function findOneBySlug($slug,$userId): ?Pack
{
return $this->createQueryBuilder('p')
->andWhere('p.slug = :val')
->setParameter('val', $slug)
->addSelect('COUNT(u) AS userLike', 'p')
->leftJoin("p.users", 'u', 'WITH', 'u.id = :userId')
->setParameter('userId', $userId)
->getQuery()
->getOneOrNullResult()
;
}
But it throws an error:
Return value of App\Repository\ArticleRepository::findOneBySlug() must be
an instance of App\Entity\Article or null, array returned
I want to add "userLike" (bool) to the Article returned entity. Anyone can help me out?

Answer 1

calling addSelect(...) on a query builder might change the return type / format.
in your particular case, the former db result was something like [... all the article properties ...] which hydration and the getOneOrNullResult turns into one Article or null.
the new format looks like
[... all the article properties ..., userlike], which hydration turns into [Article, userlike] which can't possibly turned into one Article or a null result, because it's a "more complex" array.
So you have to use a different result fetcher. Depending on what the caller of your function expects as a return value (I would expect an article ^^) you maybe should rename the function or add a virtual property on article to hide the userlike or something, so you can return just the Article or null.
So the solution that I would choose:
$result = $this->createQueryBuilder(...)
//...
->getSingleResult();
if(!$result) {
// empty result, obviously
return $result;
}
// $result[0] is usually the object.
$result[0]->userLike = $result['userLike'];
// or $result[0]->setUserLike($result['userLike'])
return $result[0];
btw: $this->createQueryBuilder($alias) in a repository automatically calls ->select($alias), so you don't have to addSelect('... userLike', 'p') and just do addSelect('... userLike')