Collection Relation

This is a special case where, in an entity, you have a toMany relation. By default, Doctrine will use an ArrayCollection to store your values. This is fine when you have a read operation, but when you try to write you can observe an issue where the response is not reflecting the changes correctly. It can lead to client errors even though the update was correct. Indeed, after an update on this relation, the collection looks wrong because ArrayCollection's indexes are not sequential. To change this, we recommend to use a getter that returns $collectionRelation->getValues(). Thanks to this, the relation is now a real array which is sequentially indexed.

<?php
// api/src/Entity/Brand.php
namespace App\Entity;
 
use ApiPlatform\Metadata\ApiResource;
use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\ORM\Mapping as ORM;
 
#[ORM\Entity]
#[ApiResource]
final class Brand
{
    #[ORM\Id, ORM\Column, ORM\GeneratedValue]
    private ?int $id = null;
 
    #[ORM\ManyToMany(targetEntity: Car::class, inversedBy: 'brands')]
    #[ORM\JoinTable(name: 'CarToBrand')]
    #[ORM\JoinColumn(name: 'brand_id', referencedColumnName: 'id', nullable: false)]
    #[ORM\InverseJoinColumn(name: 'car_id', referencedColumnName: 'id', nullable: false)]
    private $cars;
 
    public function __construct()
    {
        $this->cars = new ArrayCollection();
    }
 
    public function addCar(DummyCar $car)
    {
        $this->cars[] = $car;
    }
 
    public function removeCar(DummyCar $car)
    {
        $this->cars->removeElement($car);
    }
 
    public function getCars()
    {
        return $this->cars->getValues();
    }
 
    public function getId()
    {
        return $this->id;
    }
}

<?php
// api/src/Entity/Brand.php
namespace App\Entity;
 
use ApiPlatform\Metadata\ApiResource;
use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\ORM\Mapping as ORM;
 
#[ORM\Entity]
#[ApiResource]
final class Brand
{
    #[ORM\Id, ORM\Column, ORM\GeneratedValue]
    private ?int $id = null;
 
    #[ORM\ManyToMany(targetEntity: Car::class, inversedBy: 'brands')]
    #[ORM\JoinTable(name: 'CarToBrand')]
    #[ORM\JoinColumn(name: 'brand_id', referencedColumnName: 'id', nullable: false)]
    #[ORM\InverseJoinColumn(name: 'car_id', referencedColumnName: 'id', nullable: false)]
    private $cars;
 
    public function __construct()
    {
        $this->cars = new ArrayCollection();
    }
 
    public function addCar(DummyCar $car)
    {
        $this->cars[] = $car;
    }
 
    public function removeCar(DummyCar $car)
    {
        $this->cars->removeElement($car);
    }
 
    public function getCars()
    {
        return $this->cars->getValues();
    }
 
    public function getId()
    {
        return $this->id;
    }
}

For reference please check #1534.