PersonFormType2.php

<?php

namespace App\Form\Type;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;
use Symfony\Component\Routing\RouterInterface;
use Symfony\Component\Form\FormEvents;
use Symfony\Component\Form\FormEvent;
use Symfony\Component\Form\FormInterface;
use App\Model\Person;
use App\Form\Type\Select2Type;

class PersonFormType extends AbstractType {

    public function __construct(RouterInterface $router) {
        $this->router = $router;
    }
    
    public function buildForm(FormBuilderInterface $builder, array $options) {
          $data = $builder->getData();
          $builder
            ->add('job', Select2Type::class, [
                'label' => '¿Cuál es tu profesión?', 
                'required' => true,
                'attr' => ['data-autocomplete-url' => $this->router->generate('search_jobs')],
                'choices' => [$data->getName() => $data->getId()]
            ]);
            ->add('submit', SubmitType::class, [
                'label' => 'Enviar',
                 'attr' => ['class' => 'btn-primary btn-submit']
            ]);
        
        $formModifier = function (FormInterface $form, ?int $jobId = 0) {
            $choices = empty($jobId) ? null : [$jobId => $jobId];
            $form->add('job', Select2Type::class, [
                'label' => '¿Cuál es tu profesión?', 
                'required' => true,
                'attr' => ['data-autocomplete-url' => $this->router->generate('search_jobs')],
                'choices' => $choices,
                'data' => $jobId
            ]);
        };

        $builder->addEventListener(
            FormEvents::PRE_SUBMIT,
            function (FormEvent $event) use ($formModifier) {
                $data = $event->getData();
                $formModifier($event->getForm(), empty($data['job']) ? 0 : $data['job']);
            }
        );
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(['data_class' => Person::class]);
    }
}