<?php

namespace AppBundle\Controller;

use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Form\Extension\Core\Type as F;

class DefaultController extends Controller
{
    /**
     * @Route("/", name="homepage")
     */
    public function indexAction(Request $request)
    {
        $form = $this->get('form.factory')->createBuilder()
          ->add('field', F\ChoiceType::class,
            [ 'choices' => ['a' => 'a', 'b' => 'b']
            , 'expanded' => true
            , 'multiple' => true
            , 'attr' => ['class' => 'AAA']
            , 'choice_attr' => ['class' => 'BBB', 'required' => true]
            , 'required' => true
            ])
          ->getForm();

        // replace this example code with whatever you need
        return $this->render('default/index.html.twig', [
            'base_dir' => realpath($this->getParameter('kernel.project_dir')).DIRECTORY_SEPARATOR,
            'form' => $form->createView()
        ]);
    }
}