How can I implemented a Doctrine2 filter based on a relation?

Question

I have a Doctrine2 listener & filter that acts as a means of filtering out any unapproved/draft entities, which works fine on the entity that it's applied to, however, I don't see how to get it to work for its relations.

Lets say that entity is called Category, I then have Products related to that Category, when I do a findBy() for Products, I need the query to check that the Category they relate to is approved.

select * from products p
left join category c on p.category_id = c.id
where p.id = 5 and c.approved = true

The bits in bold are what need to be injected by my filter or equivalent.

How can I go about implementing this?

So far I have a subquery injected as part of the where in the filter, but this seems hellish, and I'm thinking there must be a better way:

class ApprovableFilter extends SQLFilter
{
    protected $listener;
    protected $entityManager;

    public function addFilterConstraint(ClassMetadata $targetEntity, $targetTableAlias)
    {
        $config = $this->getListener()->getConfiguration($this->getEntityManager(), $targetEntity->name);

        /* this bit works fine for the category */

        if (isset($config['approvable']) && $config['approvable']) {
            $column = $targetEntity->columnNames[$config['fieldName']];

            return $targetTableAlias.'.'.$column.' = true';
        }

        /* this bit works for products.. but seems like a pretty poor solution */

        if (isset($targetEntity->associationMappings['category'])) {
            $config = $this->getListener()->getConfiguration(
                $this->getEntityManager(),
                $targetEntity->associationMappings['category']['targetEntity']
            );

            return '(
                select d.id from dealership d
                where d.id = '.$targetTableAlias.'.dealership_id
                and d.'.$config['fieldName'].' = true
            ) is not null';
        }
    }

Answer 1

Your solution can be made a little more general by using annotations. I've written a gist about it at: https://gist.github.com/technetium/0c62164400a411e9ffc3713260448b25

Answer 2

The best i can think of, is to retrieve your Products via the Category object.
That way you only need to filter for the category.approved field.

For example:

public function addFilterConstraint(ClassMetadata $targetEntity, $targetTableAlias)
{
    $config = $this->getListener()->getConfiguration($this->getEntityManager(), $targetEntity->name);

    /* this bit works fine for the category */

    if (isset($config['approvable']) && $config['approvable']) {
        $column = $targetEntity->columnNames[$config['fieldName']];

        return $targetTableAlias.'.'.$column.' = true';
    }
}

Then your Category entity should have a products collection (assuming you have a Bidirectional relation).

use Doctrine\Common\Collections\ArrayCollection;

class Category {
    /**
     * @var ArrayCollection $products
     * @ORM\OneToMany(targetEntity="Product", mappedBy="category")
     */
    private $products;

    public function __construct()
    {
        $this->products = new ArrayCollection;
    }

    public function getProducts()
    {
        return $this->products;
    }
}

That way you can first retrieve your Category

$category = $this->get('doctrine')->getRepository('SomeBundle:Category')->find(5);
if( $category ) {
    //Here you now the category is approved
    $products = $category->getProducts();
}

hope this helps.

Edit:

To answer @lracicot question and to give an example for unidirectional relation: I would create a ProjectRepository method for example:

...
findByCategoryApproved( $product_id, $approved = true )
{
    $query =
        'SELECT p
         FROM AcmeBundle:Product
         LEFT JOIN p.categories c
         WHERE p.id = :id AND c.approved = :approved';
    
    return $this
        ->getEntityManager()
        ->createQuery( $query )
        ->setParameter( 'id', $product_id )
        ->setParameter( 'approved', $approved )
        ->getOneOrNullResult();
}

...

$product = $doctrine
     ->getRepository('AcmeBundle:Product')
     ->findByCategoryApproved(5);