I just can't extend the Symfony2 Form class. Tried everything

Question

I have literally tried everything to try and extend the Symfony2 Form class.

I want to add a new method to Form and call it in a controller:

$form = $this->createForm($this->get('my_form_service'), $entity);
$form->myNewMethod();

Because the Form class isn't defined as a service and is instantiated in another class (FormBuilder, line 221) then I can't see what I can do. I don't want to hack the core.

I could extend the controller class, e.g. the createForm() method returns the instantiated Form object:

// Extend Controller and do something with Form before returning

public function createForm($type, $data = null, array $options = array())
{
    return $this->container->get('form.factory')->create($type, $data, $options);

In fact How to add a new method to a php object on the fly? shows how I could do the above and add my new method that way, but my understanding is that you need to at least add __call to the Form class - which I can't do - or the added method won't be able to use $this (which I need).

I only need to add this for when the form is used in a controller. I don't need it for any CLI processing.

Any ideas how I can add a method to the Form class without hacking the core?

====================================================================

EDIT: Why am I doing this?

I want to 'silently fail' a form submit if a certain criteria is met. I believe the best way to do this would be to do this in a controller:

if ($form->isValid()) {
    if ($form->requiresSilentFail()) {
        // Silently fail
    } else {
        // As normal, add to DB etc.
    }
}

I suppose I could just do something like this:

if ($form->isValid()) {
    if ($this->get('check_my_form')->requiresSilentFail($form)) {
        // Silently fail
    } else {
        // As normal, add to DB etc.
    }
}

.... but I need to also perform a little bit of extra logic in Form::handleRequest() first, so I believe extending Form is the only option.

I'm not really familiar with Symfony, but if you want to extend classes you just do it by subclassing them (unless they're declared final, which is rarely done). Can't you do `class MyForm extends SymfonyForm`? — GordonM, Sep 29 '14 at 15:51
Subclass the form.factory service too and replace the instantiation of Form with your own class there. — user3557327, Sep 29 '14 at 16:25
I think you should be handling this with either FormEvents or the Validator component — Peter Bailey, Sep 30 '14 at 12:24

score 0 · Answer 1 · answered Sep 29 '14 at 20:44

I don't really understand why you need to extend the form class simply on your controller/service where you process the form call your method under is valid check, see below:

            $form->handleRequest($request);
            if ($form->isValid()) {
              $this->get($apiResource->getResourceHandlerName())->update($resourceData);
              $response = new Response();
              $response->setStatusCode($statusCode);
              if ($this->isSuccessFullStatusCode($statusCode)) {
                $serializedObject = $this->getSerializer()->serialize($resourceData, 'json',$serializationContext);
                $response->setStatusCode($responseStatusCode);
                $response->setContent($serializedObject);
                return $response;
            }
        }

I just can't extend the Symfony2 Form class. Tried everything

1 Answers1