Model populated with unposted data - forms

Question

I have two models, Lesson and Evaluation. Each lesson can have multiple evaluations.
I am trying to set up an embedded form which will allow users to enter all of this data at the same time.
It works fine for adding and editing data, however I have a problem if I try to remove an evaluation.
For example, I have a lesson with three evaluations attached. I then submit with form again but with one of those removed.
In the controller, I first get the lesson being edited, then get its evaluations and loop through them, printing the ids. Three ids are printed as expected.
Next, I bind the request to the form and check if it is valid. I then get the evaluations again and loop through them once more to check that they've been removed, however all three ids were still there!
If I print the raw POST data, there are only two.
Can anyone see what I have done wrong?
Here is my controller code:
public function editAction($id = NULL)
{
$lesson = new Lesson;
if ( ! empty($id))
{
$lesson = $this->getDoctrine()
->getRepository('LessonBundle:Lesson')
->find($id);
}
foreach ($lesson->getEvaluations() as $evaluation)
{
print_r($evaluation->getId());
print_r('<br />');
}
$form = $this->createForm(new LessonType(), $lesson);
$request = $this->getRequest();
if ($request->getMethod() == 'POST') {
$form->bindRequest($request);
if ($form->isValid()) {
foreach ($lesson->getEvaluations() as $evaluation)
{
print_r($evaluation->getId());
print_r('<br />');
}
die();
$em = $this->getDoctrine()->getEntityManager();
$em->persist($lesson);
$em->flush();
}
}
}
Here is my lesson form:
class LessonType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->add('evaluations', 'collection', array(
'type' => new EvaluationType(),
'allow_add' => true,
'by_reference' => false,
'allow_delete' => true,
));
}
public function getDefaultOptions(array $options)
{
return array(
'data_class' => 'LessonBundle\Entity\Lesson',
);
}
public function getName()
{
return 'Lesson';
}
}
And finally, my Evaluation form:
class EvaluationType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->add('report');
}
public function getDefaultOptions(array $options)
{
return array(
'data_class' => 'LessonBundle\Entity\Evaluation',
);
}
public function getName()
{
return 'Evaluation';
}
}
Any advice appreciated.
Thanks.

Answer 1

I think your form is not binded properly with the Class.
have a look at here http://symfony.com/doc/2.0/cookbook/form/form_collections.html
Form should look like this
$builder
->add('name lesson')
->add('evaluation', 'collection', array('type'=>new EvaluationsType()))
YOu need to create a new form class with other forms embedded.
The other way is to manually check the posted data and remove the evalauation manually in the controller and then persist the Lesson again

Answer 2

I got around in by using:
$lesson = $form->getData();