before recepie upgrade

src/Entity/Blog.php

@@ -7,11 +7,13 @@ use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
 use JetBrains\PhpStorm\Pure;
-use App\Repository\SectionRepository;
+use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;
+use Symfony\Component\String\Slugger\SluggerInterface;
 
 /**
  * @ORM\Entity(repositoryClass=BlogRepository::class)
  * @ORM\HasLifecycleCallbacks()
+ * @UniqueEntity("slug")
  */
 class Blog
 {
@@ -79,7 +81,7 @@ class Blog
 	private $comments;
 	
 	/**
-	 * @ORM\Column(type="string", length=255)
+	 * @ORM\Column(type="string", length=255, unique=true)
 	 */
 	private $slug;
 	
@@ -274,7 +276,24 @@ class Blog
 	public function setSlug(string $slug): self
 	{
 		$this->slug = $slug;
-		
 		return $this;
 	}
+	
+	
+	/**
+	 * @ORM\PrePersist
+	 */
+	public function onPrePersist()
+	{
+		$this->createdAt = new \DateTime();
+	}
+	
+	/**
+	 * @param SluggerInterface $slugger
+	 */
+	public function computeSlug(SluggerInterface $slugger)
+	{
+		$this->slug = $slugger->slug($this->title);
+	}
+	
 }