Symfony2 form: create entity on Ajax success - php

Question

I am working with Symfony2 and I am trying to create new entity Collection without page reload. My controller works fine, but I have issues with Ajax, I am NOT well familiar with it. Below is the code I already have. When I press submit button, new entity is saved in db, but entity doesn't appear on page.
CollectionController
/**
* #Route("/create-collection", name="collection_create_collection")
* #Template()
*/
public function createAction(Request $request)
{
$collection = new Collection();
$form = $this->createForm(
new CollectionType(),
$collection,
array('method' => 'POST',
'action' => $this->generateUrl('collection_create_submit'),
)
);
return array('collection'=>$collection, 'form' => $form->createView());
}
/**
* #Route("/collection_create_submit", name="collection_create_submit")
*/
public function createSubmitAction(Request $request)
{
$collection = new Collection();
$user = $this->getUser();
$form = $this->createForm(
new CollectionType(),
$collection,
array('method' => 'POST',
)
);
$form->handleRequest($request);
if ($form->isValid() && $form->isSubmitted()) {
$colname = $form["name"]->getData();
$existing = $this->getDoctrine()->getRepository('CollectionBundle:Collection')->findBy(['name' => $colname, 'user' => $user]);
if ($existing) {
return new JsonResponse(['error' => 'Collection with such name already exists']);
}
$em = $this->getDoctrine()->getManager();
$em->persist($collection);
$em->flush();
return new JsonResponse(array(
'success' => $collection
));
}
}
create.html.twig
{% include 'CollectionBundle:Collection:collectionJS.html.twig' %}
<div class="collection-create">
<h3 id="create-collection">Create a collection</h3>
<a class="close-reveal-modal" aria-label="Close">×</a>
{{ form_start(form, {'attr' : {'action' : 'collection_create_collection', 'id': 'create-collection-form'}}) }}
{{ form_widget(form) }}
<a class="button custom-close-reveal-modal" aria-label="Close">Cancel</a>
<button type="submit" value="create" class="right" onclick="createCollection();">Create</button>
{{ form_end(form) }}
</div>
<script type="application/javascript">
$('a.custom-close-reveal-modal').on('click', function(){
$('#externalModal').foundation('reveal', 'close');
});
</script>
collectionJS.html.twig
function createCollection(){
var $form = $('#create-collection-form');
$($form).submit(function(e) {
e.preventDefault();
$.ajax({
type: "POST",
url: $form.attr('action'),
data: $form.serialize()
}).done(function( data ) {
if(data.error)
{
console.log(data.error);
} else if(data.success) {
var collection = data.success;
$('.griditems').prepend('<p>' + collection + '</p>');
$('#externalModal').foundation('reveal', 'close');
}
});
});
}
UPD
The submit is triggered, but now I get undefined instead of entity. Probably, I am sending wrong json response.
UPD
I tried to encode collection entity.
In createSubmitAction I changed return to
$jsonCollection = new JsonEncoder();
$jsonCollection->encode($collection, $format = 'json');
return new JsonResponse(array(
'success' => $jsonCollection
));
How do I get this response in Ajax?

Answer 1

JsonResponse cannot transform your entities into JSON. You need to use a serializer library like JMSSerializerBundle or implement a serializing-method inside your entity.
Check the answers provided here.
How to encode Doctrine entities to JSON in Symfony 2.0 AJAX application?

Answer 2

You have to return a simple $collection object as the standard doctrine entity objects are too large in size. What I recommend is:
return new JsonResponse(array(
'success' => $collection->toArray()
));
and adding a new method to your entity class:
public function toArray(){
return array(
'id' =>$this->getId(),
'name'=>$this->getName(),
// ... and whatever more properties you need
); }