Cleanup and comments about Tags feature implementation

Author: yceruto

src/AppBundle/Entity/Post.php

@@ -186,14 +186,6 @@ public function setAuthor(User $author)
         $this->author = $author;
     }
 
-    /**
-     * Is the given User the author of this Post?
-     */
-    public function isAuthor(User $user = null)
-    {
-        return $user === $this->author;
-    }
-
     public function getComments()
     {
         return $this->comments;

src/AppBundle/Entity/Tag.php

@@ -55,6 +55,9 @@ public function getName()
      */
     public function jsonSerialize()
     {
+        // This method is called when a Tag instance needs be serialized to JSON
+        // See usage in app/Resources/views/form/fields.html.twig: tags|json_encode
+
         return $this->name;
     }
 

src/AppBundle/Form/DataTransformer/TagArrayToStringTransformer.php

@@ -37,6 +37,10 @@ public function __construct(ObjectManager $manager)
      */
     public function transform($array)
     {
+        // This transformation expects an array of Tag always thanks to
+        // Symfony\Bridge\Doctrine\Form\DataTransformer\CollectionToArrayTransformer::transform()
+        // Just remains transform this array into a comma separated string format.
+
         /* @var Tag[] $array */
         return implode(',', $array);
     }
@@ -52,17 +56,22 @@ public function reverseTransform($string)
 
         $names = explode(',', $string);
 
+        // Now we need to get the current tags and to find the new ones that should be created.
         $tags = $this->manager->getRepository(Tag::class)->findBy([
             'name' => $names,
         ]);
-
         $newNames = array_diff($names, $tags);
         foreach ($newNames as $name) {
             $tag = new Tag();
             $tag->setName($name);
             $tags[] = $tag;
+
+            // Don't worry about persisting these new tags, Doctrine is able to do it automatically
+            // thanks to cascade={"persist"} configuration in AppBundle\Entity\Post::$tags property.
         }
 
+        // This one should return an array always to transform these tags into Collection instance again.
+        // See Symfony\Bridge\Doctrine\Form\DataTransformer\CollectionToArrayTransformer::reverseTransform()
         return $tags;
     }
 }

src/AppBundle/Form/Type/DateTimePickerType.php

@@ -28,9 +28,6 @@
  */
 class DateTimePickerType extends AbstractType
 {
-    /**
-     * @var MomentFormatConverter
-     */
     private $formatConverter;
 
     public function __construct()

src/AppBundle/Form/Type/TagsInputType.php

@@ -45,8 +45,12 @@ public function buildForm(FormBuilderInterface $builder, array $options)
     {
         $builder
             ->setByReference(false)
-            ->addModelTransformer(new TagArrayToStringTransformer($this->manager))
-            ->addModelTransformer(new CollectionToArrayTransformer())
+            // We need to transform the tags collection into a comma separated string format
+            // so we are reusing an existing one to simplify the code, but you could build
+            // only one to do all transformation (i.e. Collection <-> string).
+            // Transformation flow: Collection <-> array <-> string
+            ->addModelTransformer(new CollectionToArrayTransformer(), true)
+            ->addModelTransformer(new TagArrayToStringTransformer($this->manager), true)
         ;
     }