A circular reference has been detected when serializing the object of class “App\Entity\User” (configured limit: 1)

Question

I am faced with a problem that gives me this error:

A circular reference has been detected when serializing the object of class "App\\Entity\\User&q

Answer 1

In my case I've fixed injecting the serializer service instead of creating a new Serializer instance in the controller method.

use Symfony\Component\Serializer\SerializerInterface;

//...
public function createOrder(Request $request, SerializerInterface $serializer)
{
    //...
    $json = $serializer->serialize($order, 'json', ['groups' => ['normal']]);
    //...
}