I've come up with a solution for this issue, and it does involve traits.
What I'm doing is basically trying to create several variations of a table. The relationship between the reviews is more horizontal than vertical (One type of review might have ratings, another one a video, another both). Traits are apparently perfect for horizontal relationships, so instead of creating models for each variation, I create traits.
So now my "models" look like this:
// Project/ReviewBundle/Entity/Review.php
use Project\ReviewBundle\Model\Review as BaseReview;
class Review extends BaseReview
{
}
// Project/ReviewBundle/Entity/RatedReviewTrait.php
trait RatedReviewTrait
{
}
// Project/ReviewBundle/Entity/ScoredReviewTrait.php
trait ScoredReviewTrait
{
}
And my entities look like this:
// Project/ReviewBundle/Entity/Review.php
use Project\ReviewBundle\Model\Review as BaseReview;
class Review extends BaseReview
{
}
// Project/ReviewBundle/Entity/RatedReview.php
use Project\ReviewBundle\Model\RatedReviewTrait;
class RatedReview extends Review
{
use RatedReviewTrait;
}
// Project/ReviewBundle/Entity/ScoredReview.php
use Project\ReviewBundle\Model\RatedReviewTrait;
use Project\ReviewBundle\Model\ScoredReviewTrait;
class ScoredReview extends Review
{
use RatedReviewTrait;
use ScoredReviewTrait;
}
My models stay separated from my entities and as a bonus I decouple the variations from each other – pretty awesome. The only issue I see is that this requires PHP >= 5.4.