Using Symfony2 form events to prevent overwriting fields with empty values

UserEditFormType.php.diff

diff --git a/src/Application/UserBundle/Form/UserEditFormType.php b/src/Application/UserBundle/Form/UserEditFormType.php
index ea5bf44..150da51 100644
--- a/src/Application/UserBundle/Form/UserEditFormType.php
+++ b/src/Application/UserBundle/Form/UserEditFormType.php
@@ -3,7 +3,9 @@
 namespace Application\UserBundle\Form;
 
 use Symfony\Component\Form\FormBuilder;
+use Symfony\Component\Form\FormEvents;
 use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\Event\FilterDataEvent;
 use Exercise\CommonBundle\Form\MonthType;
 use Exercise\CommonBundle\Form\DayType;
 use Exercise\CommonBundle\Form\YearType;
@@ -53,7 +55,14 @@ class UserEditFormType extends AbstractType
             ))
             ->add('website')
             ->add('occupation')
-            ->add($builder->create('aboutMe', 'textarea')->appendClientTransformer(new ApiTransformer()))
+            ->add($builder
+                ->create('aboutMe', 'textarea')
+                ->addEventListener(FormEvents::BIND_NORM_DATA, function(FilterDataEvent $event) {
+                    if (null === $event->getData()) {
+                        $event->setData($event->getForm()->getData());
+                    }
+                })
+            )
         ;
     }