Gestione del submit

ArticleController.php

<?php
namespace App\Controller;
use Symfony\Component\Routing\Annotation\Route;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use App\Form\ArticleType;
use App\Entity\Article;
class ArticleController extends Controller
{
    /**
     * @Route("/create-new", name="article_new")
     */
    public function newArticle(Request $request)
    {
        $article = new Article();
    
        $form = $this->createForm(ArticleType::class, $article);
        $form->handleRequest($request);
        if ($form->isSubmitted() && $form->isValid()) {
            
            // Il form è stato sottomesso
            $now = new \DateTime();
            $article->setCreationDateTime($now);
            $article->setLastModificationDateTime(null);
            $slug = $this->slugify($article->getTitle());
            $article->setSlug($slug);

            $em = $this->getDoctrine()->getManager();
            $em->persist($article);
            $em->flush();

            return $this->redirectToRoute('article_show', [
                'slug' => $article->getSlug()
            ]);
        }
        return $this->render('Backend/new.html.twig', [
            'form' => $form->createView()
        ]);
    }
}