[Flow] Custom Factory

[Mathis Hoffmann]

Hi,

I'm just trying to use my own factory for creating my objects. I added 
the following to Objects.yaml:

HdM\Accounting\Domain\Payment\Category\Model\PaymentCategory:
   properties:
     cache:
       object:
         factoryObjectName: 
HdM\Accounting\Domain\Payment\Category\Model\PaymentCategoryFactory
         factoryMethodName: createPaymentCategory

and created the corresponding FactoryObject. PaymentCategory is an 
interface-type which has some concrete subtypes. Depending on the user 
input my factory decides which concrete subtype to use. I created a 
fluid form with name="newPaymentCategory" and added the two parameters 
my factory requires (name:string and type:string) as text-input-fields 
using property="type"/property="name" to that form. The createAction 
requires newPaymentCategory as type PaymentCategory. I think flow should 
now recognise that there is a custom factory for type PaymentCategory 
and use my factory but it doesn't. It tries to property-map itself and 
complains that PaymentCategory does not have a setter for argument 
"type" (which is true because this argument is for my custom factory to 
determine the concrete implementation of PaymentCategory it should return).

My factory-method looks like the following:
     /**
      * @param string $type 'incoming' or 'outgoing'
      * @param string $name
      * @return 
\HdM\Accounting\Domain\Payment\Category\Model\PaymentCategory
      * @throws \InvalidArgumentException
      */
     public function createPaymentCategory ($type, $name) {
         switch ($type) {
             case 'incoming':
                 $c = new IncomingPaymentCategory();
                 break;
             case 'outgoing':
                 $c = new OutgoingPaymentCategory();
                 break;
             default:
                 throw new \InvalidArgumentException('Invalid argument 
for $type');
         }
         $c->setName($name);
         return $c;
     }

And finally the createAction is as simple as follows:
     /**
      * Adds the given new payment category object to the payment 
category repository
      *
      * @param 
\HdM\Accounting\Domain\Payment\Category\Model\PaymentCategory 
$newPaymentCategory
      * @return void
      */
     public function createAction(PaymentCategory $newPaymentCategory) {
$this->paymentCategoryRepository->add($newPaymentCategory);
         $this->addFlashMessage('Kategorie angelegt.');
         $this->redirect('index');
     }

Can anyone tell me how to force Flow to use my custom factory instead of 
it's build-in property-mapper which is not really suitable for 
polymorphic types?

Cheers
Mathis