Q: Return entity in a case if it already exist

I have entity Tag, which have unique property tagValue. When I make a POST with already exists tagValue I want to get it in response.

config/validator/tag.yaml:

App\Entity\Tag:
  constraints:
    - Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity: tagValue
  properties:
    tagValue:
      - NotBlank: ~

src/Entity/Tag.php:

<?php

namespace App\Entity;

use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\Common\Collections\Collection;
use Doctrine\ORM\Mapping as ORM;
use DateTimeInterface;
use DateTime;
use Exception;

/**
 * @ORM\Table(name="tag")
 * @ORM\Entity(repositoryClass="App\Repository\TagRepository")
 * @ORM\HasLifecycleCallbacks
 */
class Tag
{
    /**
     * @var int
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="IDENTITY")
     * @ORM\Column(type="integer")
     */
    private $id;

    /**
     * @var string
     * @ORM\Column(type="string", length=255)
     */
    private $tagValue;

    // ...
}

When I make a POST:

curl --request POST \
  --url http://127.0.0.1:8888/api/tags \
  --header 'accept: application/json' \
  --header 'content-type: application/json' \
  --header 'x-auth-token: xxxxxxxxxxxxxxxx' \
  --data '{
	"tagValue": "test"
}'

I got response with just created entity and code 201. Everything is ok, but if I’ll make this request again, as expected, I’m getting response code 400 with response body:

{
  "type": "https:\/\/tools.ietf.org\/html\/rfc2616#section-10",
  "title": "An error occurred",
  "detail": "tagValue: This value is already used.",
  "violations": [
    {
      "propertyPath": "tagValue",
      "message": "This value is already used."
    }
  ]
}

But I want exist entity include to that response.

Any ideas how to do that without breaking REST rules?

(Symfony 4.2.5, api-platform/api-pack 1.2.0)

P.S. Same question on: https://stackoverflow.com/questions/57310654/return-entity-in-a-case-if-it-already-exist-api-platform

[tylerwiegand]

I recently had this very same need but just making a query for the record in a data persister worked for me. Not sure if this is intended or not, but it feels a lot simpler than the current solution (which I did not want to mess with lol)

<?php

namespace App\DataPersister;

use ApiPlatform\Core\DataPersister\DataPersisterInterface;
use App\Entity\Entity;
use App\Repository\EntityRepository;
use Doctrine\ORM\EntityManagerInterface;

class EntityPersister implements DataPersisterInterface
{
    /**
     * @var EntityManagerInterface
     */
    private $entityManager;

    /**
     * @var EntityRepository
     */
    private $entityRepository;

    /**
     * EntityPersister constructor.
     * @param EntityManagerInterface $entityManager
     * @param EntityRepository       $entityRepository
     */
    public function __construct(
        EntityManagerInterface $entityManager,
        EntityRepository $entityRepository
    ) {

        $this->entityManager    = $entityManager;
        $this->entityRepository = $entityRepository;
    }

    public function supports($data): bool
    {
        return $data instanceof Entity;
    }

    public function persist($data): Entity
    {
        $record = $this->entityRepository->findOneBy([
            'uniqueField' => $data->getUniqueField(),
        ]);

        if($record) {
            return $record;
        }

        $this->entityManager->persist($data);
        $this->entityManager->flush();

        return $data;
    }

    public function remove($data)
    {
        $this->entityManager->remove($data);
        $this->entityManager->flush();
    }
}

[soyuka]

Might this be fixed by adding an entry in the documentation?