Symfony apply criteria in relation

I have an entity called Products

<?php
class Product
{
    /**
     * @ORM\Column(name="id", type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="IDENTITY")
     */
    private $id;

    /**
     * @ORM\ManyToOne(targetEntity="AppBundle\Entity\Product", inversedBy="list")
     * @ORM\JoinColumns({
     *   @ORM\JoinColumn(name="id_parent", referencedColumnName="id", nullable=true)
     * })
     */
    private $parent;

    /**
     * @ORM\OneToMany(targetEntity="AppBundle\Entity\Product", mappedBy="parent")
     */
    private $list;
    //... more properties
}

The getList method is like this:

public function getList()
{
    if($this->list !== null){
        return $this->list->getValues();
    }
}

Now, in the controller I have a problem, some times I need to filter the list by a property of the same entity and other times I need it with no filter.

I create the query with dql:

$query = "SELECT p
            FROM AppBundle:Product p
            WHERE (p.parent= 0 OR p.parent IS NULL)
            AND p.code != '' ";
$createdQuery= $this->em->createQuery($query)->setParameters($params);
$result= $createdQuery->getResult();

The products result from the query have the correct data, but if I try to print $products[0]->getList() it retrieve all the child products, and I only need to retrieve only the ones that has a p.code not a blank string.

Is there a way to all a specific criteria to apply to the full result of a query, or somehow pass a parameter to the getList() method to apply logic to that method to sometimes filter the results of the list and sometimes dont filter the list?

UPDATE

Example of the data I retrieve from database:

Product 1
{
    id : 1,
    parent : null,
    code: 'aa',
    list : [
        Product 2
        {
          id : 2,
          parent : object with the product 1,
          code: '',
          list : []
        }
    ]
  }
Product 3
{
    id : 3,
    parent : null,
    code: 'bb',
    list : []
}

Sometimes I only need to retrieve all the products,and sometimes I only need those witch are active = 1.

With the query in the example I retrieve all the products correctly, but AND p.code != '' only apply to the ones thar are in the root. I want to apply this filter to the list property but not always.

Solution

Either you can do it after having retrieved all data from the DB, or during the query.

After

The list that Doctrine provides you ($this->list) is an ArrayCollection which contains a matching method to return a filtered set of entities.

You have to pass a Criteria object to it such as this:

public function getList($myParam = null)
{
    if ($myParam) {
        $crit = Criteria::create();
        $crit->andWhere(Criteria::expr()->eq('myField', $myParam));
        return $this->list->matching($crit)->getValues();
    }
}

This will return all entities from $this->list having ->myField equal to $myParam

More infos around here: https://www.doctrine-project.org/projects/doctrine-orm/en/2.6/reference/working-with-associations.html#filtering-collections

During

You can also directly filter associated results by modifying the query using a Join and extra conditions:

$query = "SELECT p
            FROM AppBundle:Product p
            LEFT JOIN p.list child WITH child.active = :active
            WHERE (p.parent= 0 OR p.parent IS NULL)
            AND p.code != ''";
$createdQuery= $this->em->createQuery($query)->setParameters([
  'active' => 1
]);
$result= $createdQuery->getResult();

You can also conditionally modify the query, using a QueryBuilder (you can't miss that thing if you do Doctrine) :

$queryBuilder = $this->em->createQueryBuilder()
  ->from('AppBundle:Product', 'p')
  ->where('(p.parent= 0 OR p.parent IS NULL) AND p.code != ""');

if ($onlyActive)
    $queryBuilder
        ->leftJoin('p.list', 'child', 'child.active = :active')
        ->setParameter('active', 1);

$result = $queryBuilder->getQuery()->getResult();