Symfony serializer and ManyToMany setter - symfony

Question

I have two entity.
Book and Author
class Book
{
/**
* #ORM\Id()
* #ORM\GeneratedValue()
* #ORM\Column(type="integer")
*/
private int $id;
/**
* #ORM\Column(type="string", length=255)
*/
private string $name;
/**
* #ORM\ManyToMany(targetEntity="App\Entity\Author", fetch="EXTRA_LAZY")
* #ORM\JoinTable(name="books_authors",
* joinColumns={#ORM\JoinColumn(name="book_id", referencedColumnName="id")},
* inverseJoinColumns={#ORM\JoinColumn(name="author_id", referencedColumnName="id")}
* )
* #var PersistentCollection|ArrayCollection
*/
private $authors;
public function __construct()
{
$this->authors = 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;
}
public function getAuthors()
{
return $this->authors;
}
public function setAuthors($authors)
{
$this->authors = $authors;
}
public function addAuthor($author){
if(!$this->authors->contains($author))
$this->authors->add($author);
}
public function removeAuthor($author){
if($this->authors->contains($author)){
$this->authors->removeElement($author);
}
}
}
In BookController i try create new book and use Serializer
book body like
{
"name:"book name",
"authors":[
1,
2
]
}
In controller
$serializer = new Serializer([new ObjectNormalizer()], [new JsonEncoder()]);
$book = $this->serializer->deserialize($request->getContent(), Book::class, 'json');
try{
$this->entityManager->persist($book);
$this->entityManager->flush();
} catch (UniqueConstraintViolationException $exception){
return new JsonResponse('already exist', JsonResponse::HTTP_FOUND);
}
but on flush() I have exception:
Expected value of type "App\Entity\Author" for association field "App\Entity\Book#$authors", got "integer" instead.
because book->authors now is an id collection, but entity collection needle.
I have some variants of resolve this, but what is the best way for create and update entity?

Answer 1

You need to create EntityNormalizer like this:
[Medium post][1]
class EntityNormalizer extends ObjectNormalizer implements DenormalizableInterface
{
private $em;
public function __construct(EntityManagerInterface $em, ?ClassMetadataFactoryInterface $classMetadataFactory = null, ?NameConverterInterface $nameConverter = null, ?PropertyAccessorInterface $propertyAccessor = null, ?PropertyTypeExtractorInterface $propertyTypeExtractor = null)
{
$this->em = $em;
parent::__construct($classMetadataFactory, $nameConverter, $propertyAccessor, $propertyTypeExtractor);
}
public function supportsNormalization($data, $format = null)
{
return false;
}
public function supportsDenormalization($data, $type, $format = null)
{
return !$this->em->getMetadataFactory()->isTransient($type) && (is_string($data) || is_numeric($data));
}
public function denormalize($data, $class, $format = null, array $context = [])
{
return $this->em->find($class, $data);
}
}
[1]: https://medium.com/cloudstek/using-the-symfony-serializer-with-doctrine-relations-69ecb17e6ebd