Symfony - AJAX delete action

Controller.php

<?php
/**
 * @Route("category/delete/{id}", name="category_delete")
 * @Method({"GET", "DELETE"})
 */
public function deleteAction(Request $request, $id)
{
    /*
     * Check Permission.
     */
    $response = array(
        'success' => true,
        'message' => '',
        'html' => '',
    );

    $repository = $this->getDoctrine()->getRepository('AppBundle:Category');
    $category = $repository->find($id);

    $form = $this->createDeleteForm($category);
    if ($request->getMethod() == 'DELETE') {
        $form->handleRequest($request);
        if ($form->isSubmitted() && $form->isValid()) {
            $em = $this->getDoctrine()->getManager();
            $em->remove($category);
            $em->flush();

            // Get response ready as per your need.
            $response['success'] = true;
            $response['message'] = 'Deleted Successfully!';
        } else {
            $response['success'] = false;
            $response['message'] = 'Sorry category could not be deleted!';
        }
        return new JsonResponse($response);

        // In case you want to redirect.
        // $this->addFlash('notice', 'Deleted Successfully!');
        // return $this->redirectToRoute('category_index');
    }
    $render = $this->render(':category:delete_confirm.html.twig', array(
        'delete_form' => $form->createView(),
        'category' => $category,
    ));

    $response['html'] = $render->getContent();

    return new JsonResponse($response);
}

template.twig

{{ form_start(delete_form) }}
<div class="uk-modal-header">
    <h3 class="uk-modal-title">Delete this Category?</h3>
</div>
<p>
    Are you sure you want to delete  '{{ category.name }}'?<br/>
    This cannot be undone.
</p>
<div class="uk-modal-footer uk-text-right">
    <div>
        <button type="submit" class="md-btn md-btn-danger" title="Click to proceed!">
            <i class="uk-icon-trash"></i> Delete
        </button>
        <button type="button" class="md-btn md-btn-warning uk-modal-close">Cancel</button>
    </div>
</div>
{{ form_end(delete_form) }}

From http://stackoverflow.com/a/40734714/4074148