symfony handle request upload file is null

I’m trying to upload multiple files on Symfony but when the form is submitted the form image field returns a null object like this

object(DoctrineCommonCollectionsArrayCollection)#1455 (1) {
  ["elements":"DoctrineCommonCollectionsArrayCollection":private]=>
  array(1) {
    [0]=>
    object(AdminBundleEntityImageNew)#1717 (5) {
      ["nom":"AdminBundleEntityImageNew":private]=>
      NULL
      ["path":"AdminBundleEntityImageNew":private]=>
      NULL
      ["idimage":"AdminBundleEntityImageNew":private]=>
      NULL
      ["categorie":"AdminBundleEntityImageNew":private]=>
      NULL
      ["file":"AdminBundleEntityImageNew":private]=>
      NULL
    }
  }
}

But when I get files directly inside the request files attributes file exist. I’ve tried to upload a file by accessing the attribute in the request, it works but it still wants to upload file via Symfony $form request handler.

That’s my controller

 public function addColorAction(Request $request, Article $article)
    {
        $couleur = new Couleur();
        $form = $this->createForm('AdminBundleFormCouleurType', $couleur);
        $form->handleRequest($request);

        if ($form->isSubmitted() && $form->isValid()) {

            $em = $this->getDoctrine()->getManager();

            $files = $couleur->getImages();

            echo "<pre>";
            var_dump($files); die;
            
            $imgs = $request->files->get("adminbundle_couleur")["images"];

            foreach ($imgs as $img) {
                $image = new ImageNew();
                $image->setFile($img["file"]);
                $image->upload();
                $couleur->addImage($image);

                $em->persist($image);
                $em->flush();
            }

            $color_art_dispo = new CouleurArticleDispo();
            $color_art_dispo->setEnStock(true);
            $color_art_dispo->setArticle($article);
            $color_art_dispo->setCouleur($couleur);
            
            $em->persist($couleur);
            $em->persist($color_art_dispo);
            $em->flush();

            return $this->redirectToRoute('article_index');
        }

        return $this->render(
            'admin/article/couleur/new.html.twig', array(
            'couleur' => $couleur,
            'form' => $form->createView(),)
        );
    }

The couleur entity

class Couleur
{
    /**
     * @var int
     *
     * @ORMColumn(name="id", type="integer")
     * @ORMId
     * @ORMGeneratedValue(strategy="AUTO")
     */
    private $id;

    /**
     * @var string
     *
     * @ORMColumn(name="nom", type="string", length=255)
     * @AssertNotBlank(message="Veuillez entrer le nom de la couleur")
     */
    private $nom;

    /**
     * @var string
     *
     * @ORMColumn(name="code_couleur", type="string", length=6)
     * @AssertNotBlank(message="Veuillez entrer le code couleur correspondant")
     * @AssertLength(
     *     min=6,
     *     max=6,
     *     minMessage="Le code couleur n'est pas correct.",
     *     maxMessage="Le code couleur n'est pas correct.",
     * )
     */
    private $codeCouleur;

    /** 
     * 
     * @ORMOneToMany(targetEntity="CouleurArticleDispo", mappedBy="_couleurs")
     */
    private $colorArticles;

    /**
     * Many Colors have Many Images.
     * 
     * @ORMManyToMany(targetEntity="ImageNew",cascade={"remove"})
     * @ORMJoinTable(name="color_images",joinColumns={@ORMJoinColumn(name="color_id",referencedColumnName="id", onDelete="CASCADE")},
     *      inverseJoinColumns={@ORMJoinColumn(name="image_id", referencedColumnName="idimage", onDelete="CASCADE")}
     * )
     */
    private $images;

    public function __toString()
    {
        return (string) $this->getNom();
    }

    /**
     * Class Constructor
     */
    public function __construct() 
    {
        $this->images = new ArrayCollection();
    }
}

This is the image entity

class ImageNew
{
    /**
     * @var string
     *
     * @ORMColumn(name="nom", type="string", length=100)
     */
    private $nom;

    /**
     * @var string
     *
     * @ORMColumn(name="path", type="string", length=255)
     */
    private $path;

    /**
     * @var integer
     *
     * @ORMColumn(name="idimage",type="integer")
     * @ORMId
     * @ORMGeneratedValue(strategy="IDENTITY")
     */
    private $idimage;

    /**
     * @var AdminBundleEntityCategorie
     *
     * @ORMManyToOne(targetEntity="AdminBundleEntityCategorie",cascade={"persist"},inversedBy="slides")
     * @ORMJoinColumns({
     *   @ORMJoinColumn(name="id_categorie",referencedColumnName="idcategorie",nullable=true,onDelete="SET NULL")
     * })
     */
    private $categorie;

    /**
     * @AssertNotNull()
     * @AssertFile(
     *     maxSize = "6000k",
     *     mimeTypes = {"image/png", "image/jpg", "image/bmp"},
     *     mimeTypesMessage = "Please upload a valid Image File (PNG, JPEG or BMP)"
     * )
     */
    private $file;

    public function __toString()
    {
        return (string) $this->getPath();
    }
}

and this is the couleur type

class CouleurType extends AbstractType
{
    /**
     * {@inheritdoc}
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('nom')
            ->add('codeCouleur')
            ->add(
                'images', CollectionType::class, 
                array(
                    'label' => 'Images de l'article ayant cette couleur',
                    'entry_type' => ImageNewFileType::class,
                    'allow_add' => true,
                    'allow_delete' => true,
                )
            );
    }
}

and finally the image type

class ImageNewFileType extends AbstractType
{
    /**
     * {@inheritdoc}
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add(
            'file', FileType::class, 
            [
                'mapped' => false,
                'required' => false,
                'attr' => array(
                    'accept' => 'image/*',
                )
            ]
        );
    }
}

Answer

I think you shouldn’t add the mapped => false option in the ImageNewFileType.

https://symfony.com/doc/current/reference/forms/types/form.html#mapped

As you can see in the documentation the field is ignored when writing to the object.