How to save and edit multiple value using checkbox - symfony

Question

I am working in Symfony2 and I have a Form where I show checkboxes which came out of a Database. I want to save the selected checkboxes in the Database (mayby as a array or string like value1, value2). How can I handle this
This is my Code:
Entity:
/**
* #var string
*/
private $relevantewaben;
/**
* #return string
*/
public function getRelevantewaben()
{
return $this->relevantewaben;
}
/**
* #param string $relevantewaben
*/
public function setRelevantewaben($relevantewaben)
{
$this->relevantewaben = $relevantewaben;
}
Controller:
public function newAction()
{
$entity = new ChangeRequest();
$form = $this->createCreateForm($entity);
return $this->render('OtlgCmdbBundle:ChangeRequest:new.html.twig', array(
'entity' => $entity,
'form' => $form->createView(),
));
}
public function updateAction(Request $request, $id)
{
$em = $this->getDoctrine()->getManager();
$entity = $em->getRepository('OtlgCmdbBundle:ChangeRequest')->find($id);
if (!$entity) {
throw $this->createNotFoundException('Unable to find ChangeRequest entity.');
}
$deleteForm = $this->createDeleteForm($id);
$editForm = $this->createEditForm($entity);
$editForm->handleRequest($request);
if ($editForm->isValid()) {
$em->flush();
return $this->redirect($this->generateUrl('changerequest_edit', array('id' => $id)));
}
return $this->render('OtlgCmdbBundle:ChangeRequest:edit.html.twig', array(
'entity' => $entity,
'edit_form' => $editForm->createView(),
'delete_form' => $deleteForm->createView(),
));
}
Form:
->add('relevantewaben', 'entity', array(
'class' => 'OtlgCmdbBundle:applicant',
'label' => 'Benötigte, relevante Waben zur Umsetzung',
'property' => 'name',
'expanded' => true,
'required' => false,
'multiple' => true,
'attr' => array('class' => 'css-checkbox')

Answer 1

If you declare the relationship between you entity and OtlgCmdbBundle:applicant, where your entity is the owner side of the relationship, Doctrine will take your changes in account automatically. For example, instead of
/**
* #var string
*/
private $relevantewaben;
you should have sth like
/**
* #var \Doctrine\Common\Collections\ArrayCollection
* #ORM\OneToMany(targetEntity="applicant", mappedBy="changeRequests", cascade={"persist"})
*/
private $relevantewaben;
Take a look at : http://docs.doctrine-project.org/en/2.0.x/reference/association-mapping.html
If what you want to save is not the relationship but, in fact, the checkboxes selected themselves:
In your controller, the variable $entity has all your changes when you enter if ($editForm->isValid()) {, so you could do $entity->getRelevantewaben() to get which ones where selected.
When you have a field that's not mapped, you can access that data with $form->get('relevantewaben')->getData(), and that's the value that you have in the form field. I haven't use it to get values that were already mapped, but that can give you an idea if that's your case.