Conference URLs now use slugs instead of integer id

migrations/Version20240728050727.php

@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Auto-generated Migration: Please modify to your needs!
+ */
+final class Version20240728050727 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return '';
+    }
+
+    public function up(Schema $schema): void
+    {
+        // this up() migration is auto-generated, please modify it to your needs
+        $this->addSql('ALTER TABLE conference ADD slug VARCHAR(255)');
+        $this->addSql("UPDATE conference SET slug=CONCAT(LOWER(city), '-', year)");
+        $this->addSql('ALTER TABLE conference ALTER COLUMN slug SET NOT NULL');
+    }
+
+    public function down(Schema $schema): void
+    {
+        // this down() migration is auto-generated, please modify it to your needs
+        $this->addSql('CREATE SCHEMA public');
+        $this->addSql('ALTER TABLE conference DROP slug');
+    }
+}

migrations/Version20240728051153.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Auto-generated Migration: Please modify to your needs!
+ */
+final class Version20240728051153 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return '';
+    }
+
+    public function up(Schema $schema): void
+    {
+        // this up() migration is auto-generated, please modify it to your needs
+        $this->addSql('CREATE UNIQUE INDEX UNIQ_911533C8989D9B62 ON conference (slug)');
+    }
+
+    public function down(Schema $schema): void
+    {
+        // this down() migration is auto-generated, please modify it to your needs
+        $this->addSql('CREATE SCHEMA public');
+        $this->addSql('DROP INDEX UNIQ_911533C8989D9B62');
+    }
+}

src/Controller/ConferenceController.php

@@ -21,7 +21,7 @@ class ConferenceController extends AbstractController
         ]);
     }
 
-    #[Route('/conference/{id}', name: 'conference')]
+    #[Route('/conference/{slug}', name: 'conference')]
     public function show(Request $request, Conference $conference, CommentRepository $commentRepository): Response
     {
         $offset = max(0, $request->query->getInt('offset', 0));

src/Entity/Conference.php

@@ -6,8 +6,11 @@ use App\Repository\ConferenceRepository;
 use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
+use Doctrine\Bridge\Doctrine\Validator\Constraints\UniqueEntity;
+use Symfony\Component\String\Slugger\SluggerInterface;
 
 #[ORM\Entity(repositoryClass: ConferenceRepository::class)]
+#[UniqueEntity('slug')]
 class Conference
 {
     #[ORM\Id]
@@ -30,6 +33,9 @@ class Conference
     #[ORM\OneToMany(targetEntity: Comment::class, mappedBy: 'conference', orphanRemoval: true)]
     private Collection $comments;
 
+    #[ORM\Column(length: 255, unique: true)]
+    private ?string $slug = null;
+
     public function __construct()
     {
         $this->comments = new ArrayCollection();
@@ -44,6 +50,13 @@ class Conference
         return $this->id;
     }
 
+    public function computeSlug(SluggerInterface $slugger)
+    {
+        if(!$this->slug || '-' === $this->slug) {
+            $this->slug = (string)$slugger->slug((string)$this)->lower();
+        }
+    }
+
     public function getCity(): ?string
     {
         return $this->city;
@@ -109,4 +122,16 @@ class Conference
 
         return $this;
     }
+
+    public function getSlug(): ?string
+    {
+        return $this->slug;
+    }
+
+    public function setSlug(string $slug): static
+    {
+        $this->slug = $slug;
+
+        return $this;
+    }
 }

src/EntityListener/ConferenceEntityListener.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace App\EntityListener;
+
+use App\Entity\Conference;
+use Doctrine\Bundle\DoctrineBundle\Attribute\AsEntityListener;
+use Doctrine\ORM\Events;
+use Doctrine\Persistence\Event\LifecycleEventArgs;
+use Symfony\Component\String\Slugger\SluggerInterface;
+
+#[AsEntityListener(event: Events::prePersist, entity: Conference::class)]
+#[AsEntityListener(event: Events::preUpdate, entity: Conference::class)]
+class ConferenceEntityListener
+{
+    public function __construct(
+        private SluggerInterface $slugger,
+    ) {
+    }
+
+    public function prePersist(Conference $conference, LifecycleEventArgs $event)
+    {
+        $conference->computeSlug($this->slugger);
+    }
+
+    public function preUpdate(Conference $conference, LifecycleEventArgs $event)
+    {
+        $conference->computeSlug($this->slugger);
+    }
+}

templates/base.html.twig

@@ -16,7 +16,7 @@
             <h1><a href="{{ path('homepage') }}">Guestbook</a></h1>
             <ul>
             {%for conference in conferences %}
-                <li><a href="{{ path('conference', { id: conference.id }) }}">{{ conference }}</a></li>
+                <li><a href="{{ path('conference', { slug: conference.slug }) }}">{{ conference }}</a></li>
             {% endfor %}
             </ul>
             <hr/>

templates/conference/index.html.twig

@@ -8,7 +8,7 @@
     {% for conference in conferences %}
         <h4>{{ conference }}</h4>
         <p>
-            <a href="{{ path('conference', { id: conference.id }) }}">View</a>
+            <a href="{{ path('conference', { slug: conference.slug }) }}">View</a>
         </p>
     {% endfor %}
 {% endblock %}

templates/conference/show.html.twig

@@ -22,10 +22,10 @@
         {% endfor %}
 
         {% if previous >= 0 %}
-            <a href="{{ path('conference', { id: conference.id, offset: previous }) }}">Previous</a>
+            <a href="{{ path('conference', { slug: conference.slug, offset: previous }) }}">Previous</a>
         {% endif %}
         {% if next < comments|length %}
-            <a href="{{ path('conference', { id: conference.id, offset: next }) }}">Next</a>
+            <a href="{{ path('conference', { slug: conference.slug, offset: next }) }}">Next</a>
         {% endif %}
     {% else %}
         <div>No comments have been posted yet for this conference.</div>