How to loop form/new entity in Symfony - php

Question

I'm having an issue with looping a form in Symfony using while loop. When the user enters one student period and it matches a registration reiterate the form to let them enter a 2nd student period and then a 3rd. I'm not doing it correctly or could I reiterate entity=new Student(); to let them enter two entities .
public function createAction(Request $request){
$entity = new Student();
$form = $this->createCreateForm($entity);
$form->handleRequest($request);
if ($form->isSubmitted() && $form->isValid()) {
$em = $this->getDoctrine()->getManager();
$student = $em->getRepository('AcmeDemoBundle:Payrollperiod')
->findOneBy([
'begindate'=>$form->get('beginDate')->getData(),
'lastdate'=>$form->get('lastDate')->getData()
]);
$registration = $em->getRepository('AcmeDemoBundle:Payrollweek')
->findBystartdateAndenddate(
$form->get('beginDate')->getData(),
$form->get('lastDate')->getData()
);
$counter = count($registration);
while($counter<=2) {
if ($student){
$this->addFlash('error', 'Duplicate error: Student Period already existed.' );
return $this->redirect($this->generateUrl('student'));
}
elseif ($registration){
foreach ($registration as $reg) {
$reg->setStudentid($entity);
}
$em->persist($entity);
$em->flush();
return $this->redirect($this->generateUrl('payrollperiod'));
}
else{
$this->addFlash('error', ' does not match .');
return $this->redirect($this->generateUrl('student'));
}
}
return array(
'entity' => $entity,
'form' => $form->createView(),
);
}
}

Answer 1

Read the documentation here http://symfony.com/doc/current/reference/forms/types/form.html#allow-extra-fields on adding fields. Your UI/Front-end should created more fields when the user needs to add a second or more periods. I should generate proper Symfony form elements and then when you post, you can handle it like a standard form post, iterating over the Request since the periods will be submitted as an array.
I did something like this in the past I adding a new form row was an AJAX call to a template that described the form input fields so I wasn't having to craft form HTML in Javascript/jQuery. .append() the template results to the form-- post and process the request.