Graphql & DTO , with "Internal server error" "The manager for POPO Output must be an EntityManager"

Hi , (i use 2.5.4)

when i do:

query {
  recipeCategories {
    name
    recipes {
      name
    }
  }
}

i have the error “The manager for App\Dto\RecipeCategoryOutput must be an EntityManager”

<?php

namespace App\Entity;

use Ramsey\Uuid\Uuid;
use App\Dto\RecipeCategoryInput;
use Doctrine\ORM\Mapping as ORM;
use App\Dto\RecipeCategoryOutput;
use Doctrine\Common\Collections\Collection;
use ApiPlatform\Core\Annotation\ApiProperty;
use ApiPlatform\Core\Annotation\ApiResource;
use Doctrine\Common\Collections\ArrayCollection;

/**
 * @ApiResource(
 *   input=RecipeCategoryInput::class,
 *   output=RecipeCategoryOutput::class
 * )
 * @ORM\Table(name="o_recipe_category")
 * @ORM\Entity(repositoryClass="App\Repository\RecipeCategoryRepository")
 * @ORM\HasLifecycleCallbacks
 */
class RecipeCategory
{
    /**
     * @ApiProperty(identifier=false)
     * @ORM\Id()
     * @ORM\GeneratedValue()
     * @ORM\Column(name="r_c_id", type="integer", options={"unsigned": true})
     */
    private $id;

    /**
     * The internal primary identity key.
     *
     * @ApiProperty(identifier=true)
     * @ORM\Column(name="r_c_uuid",type="uuid", unique=true)
     */
    protected $uuid;

    /**
     * @ORM\Column(name="r_c_name", type="string", length=200)
     */
    private $name;

    /**
     * @ORM\PrePersist
     *
     * @throws Exception;
     */
    public function onPrePersist(): void
    {
        $this->uuid = Uuid::uuid4();
    }

    /**
     * @ORM\OneToMany(targetEntity="App\Entity\Recipe", mappedBy="recipeCategory", orphanRemoval=true)
     */
    private $recipes;

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

    public function getId(): ?int
    {
        return $this->id;
    }

    public function getName(): ?string
    {
        return $this->name;
    }

    public function setName(string $name): self
    {
        $this->name = $name;

        return $this;
    }

    /**
     * @return Collection|Recipe[]
     */
    public function getRecipes(): Collection
    {
        return $this->recipes;
    }



    public function getUuid()
    {
        return $this->uuid;
    }

    public function setUuid($uuid): self
    {
        $this->uuid = $uuid;

        return $this;
    }
}

<?php

namespace App\Dto;
use App\Entity\Recipe;
use Doctrine\Common\Collections\ArrayCollection;

final class RecipeCategoryOutput
{
    /**
     * @var string
     */
    public $name;

    /**
     * @var ArrayCollection<Recipe>
     */
    public $recipes;
}

<?php

namespace App\DataTransformer;

use ApiPlatform\Core\DataTransformer\DataTransformerInterface;
use App\Dto\RecipeCategoryOutput;
use App\Entity\RecipeCategory;


final class RecipeCategoryOutputDataTransformer implements DataTransformerInterface
{
    /**
     *{@inheritDoc}
     */
    public function transform($object, string $to, array $context = [])
    {
        $output = new RecipeCategoryOutput();

        $output->name = $object->getName();
        $output->recipes = $object->getRecipes();

        return $output;
    }
    /**
     * {@inheritdoc}
     */
    public function supportsTransformation($data, string $to, array $context = []): bool
    {
        return RecipeCategoryOutput::class === $to && $data instanceof RecipeCategory;
    }
}

<?php

namespace App\Entity;

use Ramsey\Uuid\Uuid;
use App\Dto\RecipeInput;
use App\Dto\RecipeOutput;
use Doctrine\ORM\Mapping as ORM;
use ApiPlatform\Core\Annotation\ApiProperty;
use ApiPlatform\Core\Annotation\ApiResource;

/**
 * @ApiResource(
 *   input=RecipeInput::class,
 *   output=RecipeOutput::class
 * )
 * @ORM\Table(name="o_recipe")
 * @ORM\Entity(repositoryClass="App\Repository\RecipeRepository")
 * @ORM\HasLifecycleCallbacks
 */
class Recipe
{
    /**
     * @ApiProperty(identifier=false)
     * @ORM\Id()
     * @ORM\GeneratedValue()
     * @ORM\Column(name="r_id", type="integer", options={"unsigned": true})
     */
    private $id;

    /**
     * The internal primary identity key.
     * @ApiProperty(identifier=true)
     * @ORM\Column(name="r_uuid",type="uuid", unique=true)
     */
    protected $uuid;

    /**
     * @ORM\Column(name="r_name", type="string", length=200)
     */
    private $name;

    /**
     * @ORM\Column(name="r_price", type="float")
     */
    private $price;

    /**
     * @ORM\PrePersist
     *
     * @throws Exception;
     */
    public function onPrePersist(): void
    {
        $this->uuid = Uuid::uuid4();
    }



    /** 
     * @ORM\ManyToOne(targetEntity="App\Entity\RecipeCategory", inversedBy="recipes")
     * @ORM\JoinColumn(name="r_fk_recipe_category_id", referencedColumnName="r_c_id", nullable=false)
     */
    private $recipeCategory;


    public function __construct()
    {
    }

    public function getId(): ?int
    {
        return $this->id;
    }

    public function getUuid()
    {
        return $this->uuid;
    }

    public function setUuid($uuid): self
    {
        $this->uuid = $uuid;

        return $this;
    }

    public function getName(): ?string
    {
        return $this->name;
    }

    public function setName(string $name): self
    {
        $this->name = $name;

        return $this;
    }

    public function getPrice(): ?float
    {
        return $this->price;
    }

    public function setPrice(float $price): self
    {
        $this->price = $price;

        return $this;
    }


    public function getRecipeCategory(): ?RecipeCategory
    {
        return $this->recipeCategory;
    }

    public function setRecipeCategory(?RecipeCategory $recipeCategory): self
    {
        $this->recipeCategory = $recipeCategory;

        return $this;
    }
}

<?php

namespace App\Dto;

use App\Entity\RecipeCategory;

final class RecipeOutput
{
    /**
     * name of recipe
     *
     * @var string
     */
    public $name;
    /**
     * price of recipe
     *
     * @var float
     */
    public $price;
    /**
     * category of recipe
     *
     * @var RecipeCategory
     */
    public $category;
}

<?php

namespace App\DataTransformer;

use ApiPlatform\Core\DataTransformer\DataTransformerInterface;
use App\Dto\RecipeOutput;
use App\Entity\RecipeCategory;

final class RecipeOutputDataTransformer implements DataTransformerInterface
{
    /**
     *{@inheritDoc}
     */
    public function transform($object, string $to, array $context = [])
    {
        $output = new RecipeOutput();

        $output->name = $object->getName();
        $output->price = $object->getPrice();
        $output->category = $object->getRecipeCategory();

        return $output;
    }
    /**
     * {@inheritdoc}
     */
    public function supportsTransformation($data, string $to, array $context = []): bool
    {
        return RecipeOutput::class === $to && $data instanceof RecipeCategory;
    }
}

i don’t want to put RecipeCategoryOutput as a api resource. thank you in advance for helping me

[alanpoulain]

Thank you @snoob, I didn’t see that the correct class to use was in the source.

Should be fixed by https://github.com/api-platform/core/pull/3594.

@mxmp210 documentation is far from perfect, don’t hesitate to improve it!

[d3bug-git]

Okay coming back to old issues, Here’s the thing : When you use data transformer for multiple objects in relation you need to convert all the output to output classes. Api platform only knows types and it will expect that return type from developer when transforming, providing or serializing objects and it’s developer’s responsibility to transform such object.

So when you say you want to output Recipies with Categories both having DTO for IO. Your transformer need to instantiate relevant transformer and loop through each object of original reciepie and category, convert it into DTO itself. You just cannot mix types and pass raw object expect it to convert automatically. That works for single item only not for related collections and thus in ReciepieOutput also must transform any related DTO in this case CategoryOutput from Category entity. Follow the trail and you will find where types do not match. Make datatransformer object, convert object(s) and you are good to go.

hello @mxmp210 i try the subresource DTO fix of @alanpoulain the api-platform transform automatically multiple relations