Paginated comments

src/Controller/ConferenceController.php

@@ -6,6 +6,7 @@ use App\Entity\Conference;
 use App\Repository\CommentRepository;
 use App\Repository\ConferenceRepository;
 use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Attribute\Route;
 use Twig\Environment;
@@ -21,11 +22,16 @@ class ConferenceController extends AbstractController
     }
 
     #[Route('/conference/{id}', name: 'conference')]
-    public function show(Environment $twig, Conference $conference, CommentRepository $commentRepository): Response
+    public function show(Request $request, Environment $twig, Conference $conference, CommentRepository $commentRepository): Response
     {
+        $offset = max(0, $request->query->getInt('offset', 0));
+        $paginator = $commentRepository->getCommentPaginator($conference, $offset);
+
         return new Response($twig->render('conference/show.html.twig', [
             'conference' => $conference,
-            'comments' => $commentRepository->findBy(['conference' => $conference], ['createdAt' => 'DESC']),
+            'comments' => $paginator,
+            'previous' => $offset - CommentRepository::COMMENTS_PER_PAGE,
+            'next' => min(count($paginator), $offset + CommentRepository::COMMENTS_PER_PAGE)
         ]));
     }
 }

src/Repository/CommentRepository.php

@@ -3,19 +3,37 @@
 namespace App\Repository;
 
 use App\Entity\Comment;
+use App\Entity\Conference;
 use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
 use Doctrine\Persistence\ManagerRegistry;
+use Doctrine\ORM\Tools\Pagination\Paginator;
 
 /**
  * @extends ServiceEntityRepository<Comment>
  */
 class CommentRepository extends ServiceEntityRepository
 {
+    public const COMMENTS_PER_PAGE = 2;
+
     public function __construct(ManagerRegistry $registry)
     {
         parent::__construct($registry, Comment::class);
     }
 
+    public function getCommentPaginator(Conference $conference, int $offset): Paginator
+    {
+        $query = $this->createQueryBuilder('c')
+            ->andWhere('c.conference = :conference')
+            ->setParameter('conference', $conference)
+            ->orderBy('c.createdAt', 'DESC')
+            ->setMaxResults(self::COMMENTS_PER_PAGE)
+            ->setFirstResult($offset)
+            ->getQuery()
+        ;
+
+        return new Paginator($query);
+    }
+
     //    /**
     //     * @return Comment[] Returns an array of Comment objects
     //     */

templates/conference/show.html.twig

@@ -6,6 +6,8 @@
     <h2>{{ conference }} Conference<h2>
 
     {% if comments|length > 0 %}
+        <div>There are {{ comments|length }} comments.</div>
+
         {% for comment in comments %}
             {% if comment.photoFilename %}
                 <img src="{{ asset('uploads/photos/' ~ comment.photofilename) }}" style="max-width: 200px"/>
@@ -18,6 +20,13 @@
 
             <p>{{ comment.text }}</p>
         {% endfor %}
+
+        {% if previous >= 0 %}
+            <a href="{{ path('conference', { id: conference.id, offset: previous }) }}">Previous</a>
+        {% endif %}
+        {% if next < comments|length %}
+            <a href="{{ path('conference', { id: conference.id, offset: next }) }}">Next</a>
+        {% endif %}
     {% else %}
         <div>No comments have been posted yet for this conference.</div>
     {% endif %}