Single position to restrict access to a Doctrine entity - symfony

Question

I've just started working with Doctrine and built a simple blog project. One of my requirements is that a blog post should not be visible to anybody (for simpleness, skip an editor's interface) until the publish date is reached.
As far as I see, it's obvious to do so using a custom repository. Let's extend the find method the following way:
public function find($id, $lockMode = null, $lockVersion = null)
{
/** #var Post $post */
$post = parent::find($id, $lockMode, $lockVersion);
if($post->getCreatedAt() > new \DateTime()) {
return null;
}
return $post;
}
This restricts the access for a page showing a single Post entity. For an overview page, the same can be done using a custom method:
public function findForOverview()
{
$query = $this->createQueryBuilder('p')
->where('p.createdAt < CURRENT_TIMESTAMP()')
->orderBy('p.createdAt', 'DESC')
->getQuery();
return $query->getResult();
}
So, even for this simple requirement, I've already written two custom methods. If I continue to work on my project, other restriction limitations might occur and additional ways to load that entity might arise. And as far as I see, for each case I have to implement the logic for all access guards.
Is there no simpler way to do that? I'm thinking of something like an annotation or an "entity load listener" that makes it simple to write one single entry point for all such checks - making it impossible to forget such checks...

Answer 1

Such restrictions are usually implemented by using mechanism of SQL filters in Doctrine. Implementation of this filter works on lower level then DQL and allows you to apply modifications for SQL query being constructed. In your case it may look like this:
namespace App\ORM\Filter;
use App\Entity\Post;
use Doctrine\ORM\Mapping\ClassMetadata;
use Doctrine\ORM\Query\Filter\SQLFilter;
class PostVisibilityFilter extends SQLFilter
{
/**
* Gets the SQL query part to add to a query.
*
* #param ClassMetadata $targetEntity
* #param string $targetTableAlias
* #return string The constraint SQL if there is available, empty string otherwise
*/
public function addFilterConstraint(ClassMetadata $targetEntity, $targetTableAlias): string
{
if ($targetEntity->name !== Post::class) {
return '';
}
return sprintf('%s.%s >= now()', $targetTableAlias, $targetEntity->getColumnName('createdAt'));
}
}