class EntityReferenceSupportedNewEntitiesConstraintValidator

class EntityReferenceSupportedNewEntitiesConstraintValidator extends ConstraintValidator implements ContainerInjectionInterface {
    
    /**
     * The workspace manager.
     *
     * @var \Drupal\workspaces\WorkspaceManagerInterface
     */
    protected $workspaceManager;
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * The workspace information service.
     *
     * @var \Drupal\workspaces\WorkspaceInformationInterface
     */
    protected $workspaceInfo;
    
    /**
     * Creates a new EntityReferenceSupportedNewEntitiesConstraintValidator instance.
     */
    public function __construct(WorkspaceManagerInterface $workspaceManager, EntityTypeManagerInterface $entityTypeManager, WorkspaceInformationInterface $workspace_information) {
        $this->workspaceManager = $workspaceManager;
        $this->entityTypeManager = $entityTypeManager;
        $this->workspaceInfo = $workspace_information;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('workspaces.manager'), $container->get('entity_type.manager'), $container->get('workspaces.information'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function validate($value, Constraint $constraint) {
        // The validator should run only if we are in a active workspace context.
        if (!$this->workspaceManager
            ->hasActiveWorkspace()) {
            return;
        }
        $target_entity_type_id = $value->getFieldDefinition()
            ->getFieldStorageDefinition()
            ->getSetting('target_type');
        $target_entity_type = $this->entityTypeManager
            ->getDefinition($target_entity_type_id);
        if ($value->hasNewEntity() && !$this->workspaceInfo
            ->isEntityTypeSupported($target_entity_type)) {
            $this->context
                ->addViolation($constraint->message, [
                '%collection_label' => $target_entity_type->getCollectionLabel(),
            ]);
        }
    }

}