Remove blank fields

IgnoreBlankFieldListener

<?php
/**
 * http://www.rjguevara.com/2013/02/symfony-2-ignorar-campos-vacios-en.html
*/
namespace Acme\TestBundle\Form\Listener;
 
use Symfony\Component\Form\FormEvent;
use Symfony\Component\Form\FormEvents;
use Symfony\Component\Form\FormFactoryInterface;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
class IgnoreBlankFieldListener implements EventSubscriberInterface
{
    private $factory;
    private $name;
 
    public function __construct(FormFactoryInterface $factory, $name)
    {
        $this->factory = $factory;
        $this->name = $name;
    }
    
    public static function isNotEmpty($var )
    {
        if(is_array($var))
        {
            $notempty = false;
            
            foreach( $var as $v )
            {
                $notempty = $notempty || !IgnoreBlankFieldListener::isNotEmpty($v);
            }
            
            return $notempty;
        }
        else
            return !empty ($var);
    }
    
    public static function isEmpty( $var )
    {
        
        return IgnoreBlankFieldListener::isNotEmpty($var);
    }
 
    public function preBind(FormEvent $event)
    {

        $data = $event->getData();
        $form = $event->getForm();

        $data_name = isset($data[$this->name])?$data[$this->name]:null;
        
        if($data_name && IgnoreBlankFieldListener::isEmpty($data_name) )
        {
           unset( $data[$this->name] );
           $event->setData($data);
           $form->remove($this->name);
        }else{ //Additional check for children forms
            if($form->has($this->name)){
                $field = $form->get($this->name);
                if(!$field->getData() || $field->isEmpty())
                {
                    $form->remove($this->name);
                }
            }
        }
    }

    public static function getSubscribedEvents() {
        return array(
            FormEvents::PRE_BIND => 'preBind',
            );
    }
}