[Flow] Custom Property Mapper and Validation

[Mathis Hoffmann]

Hello,

I've written my own type converter that allows property mapping of 
inherited types. For example I have a CustomerInterface, a Customer 
which is abstract and implements the interface and to concrete classes 
BusinessCustomer and PrivateCustomer that inherit from Customer. I have 
written an abstract type converter (http://pastebin.com/jmHtdrEj) that 
provides the functionality and inherits from PersistentObjectConverter. 
It basically determines the concrete type based on a 'type'-parameter 
from the webform, adjusts the $targetType-variable and hands the request 
over to the convertFrom-method of PersistentObjectConverter. For every 
interface-type I create a seperate converter that inherit from my 
abstract converter and do some configuration (for example configure 
which conrete types exists and so on). For the customer-example it looks 
like the following: http://pastebin.com/dK1cvavQ .

That works quite fine - exept that fact that the validation does not 
work. Using my custom converter Flow only validates before persisting 
the object and not before passing the mapped object to the controller. 
Therefore I cannot display any validation errors in the form - instead I 
get an uncaught exception.

Does anyone know how to turn on validation in the property mapper? I 
thought it should work because I only change the target type in my 
custom converter and hand the work on to the Flow-internal converter.

Cheers
Mathis