Symfony3 FOS UserBundle how to load choice as entity - fosuserbundle

Question

I am using Symfony3.1 with FOS UsersBundle and I want some added fields to be loaded as specific Entity.
In RegistrationType I have
->add('country', ChoiceType::class, array(
'label' => 'label.country',
'required' => false,
'placeholder' => 'label.select_country',
'choices' => array(
'France' => '7v8tqr',
),
))
In my Entity User I have
/**
* #ORM\OneToOne(targetEntity="Country")
* #ORM\JoinColumn(name="country", referencedColumnName="short")
*/
protected $country;
I can't use the EntityType as it loads every available entity and I use the same kind of field for provinces and cities which are quite huge (I manage their content with javascript).
When I load a registered user, the country field is served as a Country Entity but when I register a new user or modify an existing one, I only have the string "short" which causes an error Expected value of type "AppBundle\Entity\Country" for association field "AppBundle\Entity\User#$country", got "string" instead..
Is there a solution ?

Answer 1

Thanks to #mcriecken who led me in the right direction, I have implemented the following solution, using an EventListener
in services.yml
app_user.registration:
class: AppBundle\EventListener\UserRegistrationListener
arguments: ['#doctrine.orm.entity_manager']
tags:
- { name: kernel.event_subscriber }
and the EventListener UserRegistrationListener.php
<?php
namespace AppBundle\EventListener;
use FOS\UserBundle\FOSUserEvents;
use FOS\UserBundle\Event\FormEvent;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpFoundation\RedirectResponse;
use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
use Doctrine\ORM\EntityManager;
class UserRegistrationListener implements EventSubscriberInterface
{
protected $em;
public function __construct(EntityManager $em)
{
$this->em = $em;
}
/**
* {#inheritDoc}
*/
public static function getSubscribedEvents()
{
return array(
FOSUserEvents::REGISTRATION_SUCCESS => 'onRegistrationSuccess',
);
}
public function onRegistrationSuccess(FormEvent $event)
{
$form = $event->getForm()->getData();
//Gets the locations
$form->setCountry($this->getCountry($form->getCountry()));
$form->setProvince($this->getProvince($form->getProvince()));
$form->setCity($this->getCity($form->getCity()));
}
//Loads the country as an entity
public function getCountry($short)
{
if ($short == null) return null;
$repository = $this->em->getRepository('AppBundle:Country');
return $repository->findOneByShort($short);
}
//Loads the province as an entity
public function getProvince($short)
{
if ($short == null) return null;
$repository = $this->em->getRepository('AppBundle:Province');
return $repository->findOneByShort($short);
}
//Loads the city as an entity
public function getCity($short)
{
if ($short == null) return null;
$repository = $this->em->getRepository('AppBundle:City');
return $repository->findOneByShort($short);
}
}
Then at the end my FOS User object contains COuntry, Province and City as Objects and it can be saved to DB :-)