symfony2 - adding choices from database

Question

I am looking to populate a choice box in symfony2 with values from a custom query. I have tried to simplify as much as possible.

Controller

class PageController extends Controller
{

    public function indexAction()
    {
      $fields = $this->get('fields');
      $countries =  $fields->getCountries(); // returns a array of countries e.g. array('UK', 'France', 'etc')
      $routeSetup = new RouteSetup(); // this is the entity
      $routeSetup->setCountries($countries); // sets the array of countries

      $chooseRouteForm = $this->createForm(new ChooseRouteForm(), $routeSetup);


      return $this->render('ExampleBundle:Page:index.html.twig', array(
        'form' => $chooseRouteForm->createView()
      ));

    }
}

ChooseRouteForm

class ChooseRouteForm extends AbstractType
{

  public function buildForm(FormBuilderInterface $builder, array $options)
  {

    // errors... ideally I want this to fetch the items from the $routeSetup object 
    $builder->add('countries', 'choice', array(
      'choices' => $this->routeSetup->getCountries()
    ));

  }

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

Answer 1

You could pass the choices to your form using..

$chooseRouteForm = $this->createForm(new ChooseRouteForm($routeSetup), $routeSetup);

Then in your form..

private $countries;

public function __construct(RouteSetup $routeSetup)
{
    $this->countries = $routeSetup->getCountries();
}

public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder->add('countries', 'choice', array(
        'choices' => $this->countries,
    ));
}

Updated (and improved) for 2.8+

Firstly you don't really need to pass in the countries as part of the route object unless they are going to be stored in the DB.

If storing the available countries in the DB then you can use an event listener. If not (or if you don't want to use a listener) you can add the countries in the options area.

Using Options

In the controller..

$chooseRouteForm = $this->createForm(
    ChooseRouteForm::class,
    // Or the full class name if using < php 5.5
    $routeSetup,
    array('countries' => $fields->getCountries())
);

And in your form..

public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder->add('countries', 'choice', array(
        'choices' => $options['countries'],
    ));
}

public function configureOptions(OptionsResolver $resolver)
{
    $resolver
        ->setDefault('countries', null)
        ->setRequired('countries')
        ->setAllowedTypes('countries', array('array'))
    ;
}

Using A Listener (If the countries array is available in the model)

In the controller..

$chooseRouteForm = $this->createForm(
    ChooseRouteForm::class,
    // Or the full class name if using < php 5.5
    $routeSetup
);

And in your form..

public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder
        ->addEventListener(FormEvents::PRE_SET_DATA, function(FormEvent $event) {
            $form = $event->getForm();
            /** @var RouteSetup $routeSetup */
            $routeSetup = $event->getData();

            if (null === $routeSetup) {
                throw new \Exception('RouteSetup must be injected into form');
            }

            $form
                ->add('countries', 'choice', array(
                    'choices' => $routeSetup->getCountries(),
                ))
            ;
        })
    ;
}