Symfony2 choice field not working

Question

I asked a question here How to use Repository custom functions in a FormType but nobody anwsered, so i did a little digging and advanced a little but i still get this error:

Notice: Object of class Proxies\__CG__\Kpr\CentarZdravljaBundle\Entity\Category 
could not be converted to int in /home/kprhr/public_html/CZ_Symfony/vendor/symfony/symfony/src/Symfony/Component/Form/Extension/Core/ChoiceList/ChoiceList.php line 457 

Now this is how my CategoryType looks like:

<?php

namespace Kpr\CentarZdravljaBundle\Form\Type;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolverInterface;
use Symfony\Bridge\Doctrine\RegistryInterface;

class CategoryType extends AbstractType
{
    private $doctrine;

    public function __construct(RegistryInterface $doctrine)
    {
        $this->doctrine = $doctrine;
    }
    public function setDefaultOptions(OptionsResolverInterface $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => 'Kpr\CentarZdravljaBundle\Entity\Category',
            'catID' => null,
        ));
    }
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $someId = $builder->getData()->getId();
        $param = ($someId) ? $someId : 0;
        $catID = $options['catID'];
        $builder->add('name', 'text', array('attr'   =>  array('class' => 'span6')));
        $builder->add('file', 'file', array('image_path' => 'webPath', 'required' => false));
        $builder->add('parent', 'choice', array(
                    'choices' => $this->getAllChildren($catID),
                    'required' => false,
                    'attr'   =>  array('data-placeholder' => '--Izaberite Opciju--'),
                    ));
        $builder->add('tags', 'tag_selector', array(
            'required'  => false,
        ));
        $builder->add('status', 'choice', array(
            'choices'   => array('1' => 'Aktivna', '0' => 'Neaktivna'),
            'required'  => true,
        ));
        $builder->add('queue', 'text', array('attr'   =>  array('class' => 'span3')));
    }
    private function getAllChildren($catID)
    {
        $choices = array();
        $children = $this->doctrine->getRepository('KprCentarZdravljaBundle:Category')->findByParenting($catID);

        foreach ($children as $child) {
            $choices[$child->getId()] = $child->getName();
        }

        return $choices;
    }

    public function getName()
    {
        return 'category';
    }

}

I am accessing the CategoryRepository function findByParenting($parent) from the CategoryType and I am getting the array populated with accurate data back from the function getAllChildren($catID) but the error is there, i think that Symfony framework is expecting an entity field instead of choice field, but dont know how to fix it. I also changet the formCreate call in the controller giving $this->getDoctrine() as an argument to CategoryType():

$form = $this->createForm(new CategoryType($this->getDoctrine()), $cat, array('catID' => $id));

Answer 1

Ok i managed to resolve the dilemma. The answer was easy all I had to do is change

$builder->add('parent', 'choice', array(
 'choices' => $this->getAllChildren($catID),
 'required' => false,
 'attr'   =>  array('data-placeholder' => '--Izaberite Opciju--'),
));

to this:

 $builder->add('parent', 'entity', array(
                'class' => 'KprCentarZdravljaBundle:Category',
                'choices' => $this->getAllChildren($catID),
                'property' => 'name',
                'required' => false,
                'attr'   =>  array('data-placeholder' => '--Izaberite Opciju--'),
                ));

And change the getAllChildren(..) function so that it returns objects

private function getAllChildren($catID)
{
    $choices = array();
    $children = $this->doctrine->getRepository('KprCentarZdravljaBundle:Category')->findByParenting($catID);

    foreach ($children as $child) {
        $choices[$child->getId()] = $child->getName();
    }

    return $choices;
}

I changed it to:

private function getAllChildren($catID)
{
    $children = $this->doctrine->getRepository('KprCentarZdravljaBundle:Category')->findByParenting($catID)

    return $children;
}

Lots of thanks to user redbirdo for pointing out the choices option on an entity field.