Let’s suppose we have an entity class and a generic FormType corresponding to the entity

class Entry {
    protected $start_time;
    protected $end_time;
    protected $confirmed; // Boolean

    // ... Other fields and getters and setters
}

On the CRUD of this entity, you might not want to allow any modification on start_time or end_time if the entity has been confirmed or in the above case when $confirmed === true

Here are couple of ways this can be solved:

1. Using the EntityManager you can retrieve original data of the entity. $em->getUnitOfWork()->getOriginalEntityData($entity) returns an array with old data of an entity which can be used to reset the data.

   if($form->isSubmitted() && $editForm->isValid()) {
       // The form was submitted
       if($confirmed === true) { // if the entity was confirmed previously
           $oldData = $em->getUnitOfWork()->getOriginalEntityData($entity);
           $entity->setStartTime($oldData['start_time']);
           $entity->setEndTime($oldData['end_time']);
       }
       // After this you can happily persist the data
       $em->persist($entity);
       $em->flush();
   }
   

2. Using Form Events

   The following is a Symfony 3 Solution, try this solution for Symfony 2.

   class EntityType extends AbstractType
   {
       public function buildForm(FormBuilderInterface $builder, array $options)
       {
           // ....
           // ....
           // Your form fields
   
           $builder->addEventListener(FormEvents::POST_SET_DATA, array($this, 'onPreSetData'));
       }
   
   
       public function onPreSetData(FormEvent $event) {
           /** @var YourEntity $entity */
           $entity = $event->getData();
           $form = $event->getForm();
   
           if($entity instanceof YourEntity) {
               if ($entity->getTimesheetEntry()->getTimeApproved() === true) {
                   $config = $form->get('start_time')->getConfig();
                   $options = $config->getOptions();
                   $options['disabled'] = true;
                   $form->add('start_time', get_class($config->getType()->getInnerType()), $options);
   
                   $config = $form->get('end_time')->getConfig();
                   $options = $config->getOptions();
                   $options['disabled'] = true;
                   $form->add('end_time', get_class($config->getType()->getInnerType()), $options);
               }
           }
   
       }
   }