Extend existing DataObject

[BojanHribernik]

Hello

I am trying to extend existing DataObject with additional "virtual" fields not in the database. Is this possible?

I have been struggling with this for two days now ... First I tried to create a Custom Operator, but it gets really complex -> I need to add config generator and field factory and javascript file ... and it still does not work as expected.

<?php

namespace App\GraphQL\DataObjectQueryFieldConfigGenerator;

use Pimcore\Bundle\DataHubBundle\GraphQL\DataObjectQueryOperatorConfigGenerator\Base;

class ElementParent extends Base
{
    public function getGraphQlType($typeName, $nodeDef, $class = null, $container = null, $params = []): Type
    {
        return Type::int(); // how can I return for example `ProductCategory` type here?
    }
}

I cannot get the correct type, or I get the correct type, but the wrong resolver executes, and so on ... so I figured that Custom Operator is not the way to go. Am I wrong?

So what is the best way to add a custom field to existing GraphQL DataObject definition?

Thanks