Symfony: call form handleRequest but avoid entity persist

Question

I have an entity that models a search form and a form type, I use that form for searching purposes only and I don't want that entity to be modified in database, so, when I do this:

$formModelEntity = $em->getRepository('AppBundle:SearchForm')
                      ->findOneBy(array('name' => 'the_model'));
$formModelForm = $this->createForm(new SearchFormType(), $formModelEntity, array('action' => $this->generateUrl('dosearch'), 'method' => 'POST'));
$formModelForm->handleRequest($request); //or ->submit($request);
if ($formModelForm->isValid())
{
     $formInstanceEntity->setFieldsFromModel($formModelEntity);
     $em->persist($formInstanceEntity);
     $em->flush();
}

The $formModelEntity changes are persisted to database, I want to avoid this but still want to take advantage of handleRequest ability to update the entity with all POST values (for read only purposes).

Is this possible?

Answer 1

In symfony, you only have to persist a new entity. If you update an existing entity found by your entity manager and then flush, your entity will be updated in database even if you didn't persist it.

Edit : you can detach an entity from the entity manager before flushing it using this line of code :

$em->detach($formModelEntity);