getIdentifierFieldNames example

class IdReader
{
    private ObjectManager $om;
    private ClassMetadata $classMetadata;
    private bool $singleId;
    private bool $intId;
    private string $idField;
    private ?self $associationIdReader = null;

    public function __construct(ObjectManager $om, ClassMetadata $classMetadata)
    {
        $ids = $classMetadata->getIdentifierFieldNames();
        $idType = $classMetadata->getTypeOfField(current($ids));

        $this->om = $om;
        $this->classMetadata = $classMetadata;
        $this->singleId = 1 === \count($ids);
        $this->intId = $this->singleId && \in_array($idType, ['integer', 'smallint', 'bigint']);
        $this->idField = current($ids);

        // single field association are resolved, since the schema column could be an int         if ($this->singleId && $classMetadata->hasAssociation($this->idField)) {
            $this->associationIdReader = new self($om, $om->getClassMetadata(
                

public function isReadable(string $class, string $property, array $context = []): ?bool
    {
        return null;
    }

    public function isWritable(string $class, string $property, array $context = []): ?bool
    {
        if (
            null === ($metadata = $this->getMetadata($class))
            || ClassMetadata::GENERATOR_TYPE_NONE === $metadata->generatorType
            || !\in_array($property, $metadata->getIdentifierFieldNames(), true)
        ) {
            return null;
        }

        return false;
    }

    private function getMetadata(string $class): ?ClassMetadata
    {
        try {
            return $this->entityManager->getClassMetadata($class);
        }