Symfony2 - validating multiple fields, DTO, no annotations - forms

Question

I know that similar questions have been asked here on SO, but answers don't satisfy me.
Having following:
Standard form with fields foo, bar, baz, bat, x
DTO (not entity, dummy object, no annotations)
Constraints on some fields attached using FormBuilder
Form is used in multiple places.
In some places that form is used, I would like to add single validator to fields foo, bar, baz. This validator can get only values of those fields or whole propagated DTO. It should have access to DI Container to call service that will check data against database.
For now I'm thinking about one of two solutions:
Adding extra constraint to the form in controllers that require it (sound dirty)
Adding extra field to form constructor/DTO (not boolean but business logic that tells if extra validation is needed) and adding extra constraint to form.
Problem is that I can't figure out how to handle either of those cases.
Finally, I want to emphasize that I don't want to use validation groups and annotations - both will add extra dependencies and logic to DTO.

Answer 1

Found the answer. For short answer you can check out This Matt Daum post.
Here's full example, presenting not only how to create custom form validator, but also how to inject services and extra data to form (because that was my case).
If you want simple receipe, go straight to the bottom.
Let's have DTO:
class MyFormDTO
{
/** #var string */
private $name;
/** #var string */
private $surname;
/** #var string */
private $phone;
/** getters and setters ommited */
}
Now, define dependencies in form. First two are services, last one (Calendar) is some extra data needed from controller.
class MyForm extends AbstractType
{
(fields hidden)
/**
* #param Sender $sender
* #param TranslatorInterface $translator
* #param Calendar $calendar
*/
public function __construct(Sender $sender, TranslatorInterface $translator, Calendar $calendar)
{
$this->translator = $translator;
$this->sender = $sender;
$this->calendar = $calendar;
}
}
Now there are two ways - if you only need services in your form, you can just define your form as a service. If you, like me, need extra data, you need to write form factory service:
class MyFormFactory
{
(fields hidden)
/**
* #param Sender $sender
* #param TranslatorInterface $translator
*/
public function __construct(Sender $sender, TranslatorInterface $translator)
{
$this->sender = $sender;
$this->translator = $translator;
}
/**
* #param Calendar $calendar
*
* #return MyForm
*/
public function getMyForm(Calendar $calendar)
{
return new MyForm($this->sender, $this->translator, $calendar);
}
}
Let's define this factory as a service with right dependencies:
mybundle.form.myform_factory:
class: MyBundle\Service\FormFactory\MyFormFactory
arguments: [ #text_message.sender, #translator ]
How to get the form in controller? Easy as that:
class MyController extends Controller
{
/**
* #ParamConverter("calendar", options={"mapping"={"calendarId":"id"}})
*
* #param Request $request
* #param Calendar $calendar
*
* #return Response
* #throws Exception
*/
public function myAction(Request $request, Calendar $calendar)
{
$formDTO = new MyFormDto();
$myForm = $this->get('mybundle.form.myform_factory')->getMyForm($calendar);
$form = $this->createForm($myForm, $formDTO);
(handling post hidden)
}
}
And now the most important part - we have services injected properly into our form. How to use them and validate selected data? like this:
class MyForm extends AbstractType
{
(fields hidden, constructor shown in previous example)
/**
* #param FormBuilderInterface $builder
* #param array $options
*/
public function buildForm(FormBuilderInterface $builder, array $options)
{
/** #var MyFormDTO $myDTO */
$myDTO = $options['data'];
(build form as usual, using services and data from $options and $this->calendar injected by controller and factory)
}
/**
* #param OptionsResolverInterface $resolver
*/
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
parent::setDefaultOptions($resolver);
$resolver->setDefaults([
'csrf_protection' => true,
'constraints' => [
new Callback(function (MyFormDTO $data, ExecutionContextInterface $context) //notice that we have access to fully propageted DTO here
{
//use injected service
$isValid = $this->sender->validateSomething($data->getSurname(), $data->getPhone());
if (false === $isValid)
{
$context
->buildViolation($this->translator->trans('wrong_surname_phone_pair'))
->addViolation();
}
return $isValid;
})
],
]);
}
}