How to fix Serialization of 'Symfony\Component\HttpFoundation\File\File' is not allowed?

Question

symfony

Added a ManyToMany relationship to the Customer implements UserInterface class with the Specialist class, which contains File in its properties. Got an error

Serialization of 'Symfony\Component\HttpFoundation\File\File' is not allowed

How to fix it without crutches?
Google suggests making a crutch in the form of an entity of a bundle between classes or specifying rules for serializing a field with File. Is there a better solution?
Entity code:

<?php

namespace App\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Security\Core\User\UserInterface;


use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;
use Symfony\Component\Validator\Constraints as Assert;


/**
 * @ORM\Entity(repositoryClass="App\Repository\CustomerRepository")
 * @UniqueEntity("email")
 */
class Customer implements UserInterface
{

    /**
     * @ORM\Id()
     * @ORM\GeneratedValue()
     * @ORM\Column(type="integer")
     */
    private $id;

    /**
     * Основной e-mail | логин
     * @ORM\Column(type="string", length=180, unique=true)
     * @Assert\Email
     */
    private $email;

    /**
     * Роли
     *
     * @ORM\Column(type="json")
     */
    private $roles = [];

    /**
     * @var string The hashed password
     * @ORM\Column(type="string")
     */
    private $password;

    /**
     * Имя
     * @ORM\Column(type="string", length=255)
     */
    private $name;


    /**
     * @ORM\ManyToOne(targetEntity="App\Entity\Specialist", inversedBy="customers")
     */
    private $manager;


    public function getId(): ?int
    {
        return $this->id;
    }

    public function getEmail(): ?string
    {
        return $this->email;
    }

    public function setEmail(string $email): self
    {
        $this->email = $email;

        return $this;
    }

    /**
     * A visual identifier that represents this user.
     *
     * @see UserInterface
     */
    public function getUsername(): string
    {
        return (string) $this->email;
    }

    /**
     * @see UserInterface
     */
    public function getRoles(): array
    {
        $roles = $this->roles;
        // guarantee every user at least has ROLE_USER
        $roles[] = 'ROLE_DISACTIVE_CUSTOMER';

        return array_unique($roles);
    }

    public function setRoles(array $roles): self
    {
        $this->roles = $roles;

        return $this;
    }

    /**
     * @see UserInterface
     */
    public function getPassword(): string
    {
        return (string) $this->password;
    }

    public function setPassword(string $password): self
    {
        $this->password = $password;

        return $this;
    }

    /**
     * @see UserInterface
     */
    public function getSalt()
    {
        // not needed when using the "bcrypt" algorithm in security.yaml
    }

    /**
     * @see UserInterface
     */
    public function eraseCredentials()
    {
        // If you store any temporary, sensitive data on the user, clear it here
        // $this->plainPassword = null;
    }

    public function getName(): ?string
    {
        return $this->name;
    }

    public function setName(string $name): self
    {
        $this->name = $name;

        return $this;
    }

    public function getManager(): ?Specialist
    {
        return $this->manager;
    }

    public function setManager(?Specialist $manager): self
    {
        $this->manager = $manager;

        return $this;
    }

}


<?php

namespace App\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\HttpFoundation\File\File;
use Symfony\Component\HttpFoundation\File\UploadedFile;
use Vich\UploaderBundle\Entity\File as EmbeddedFile;
use Vich\UploaderBundle\Mapping\Annotation as Vich;

/**
 * @ORM\Entity(repositoryClass="App\Repository\SpecialistRepository")
 * @Vich\Uploadable
 */
class Specialist
{
    /**
     * @ORM\Id()
     * @ORM\GeneratedValue()
     * @ORM\Column(type="integer")
     */
    private $id;
    /**
     * NOTE: This is not a mapped field of entity metadata, just a simple property.
     *
     * @Vich\UploadableField(mapping="specialist_image", fileNameProperty="image.name", size="image.size", mimeType="image.mimeType", originalName="image.originalName", dimensions="image.dimensions")
     *
     * @var File
     */
    private $imageFile;

    /**
     * @ORM\Embedded(class="Vich\UploaderBundle\Entity\File")
     *
     * @var EmbeddedFile
     */
    private $image;

    /**
     * @ORM\Column(type="datetime")
     *
     * @var \DateTime
     */
    private $updatedAt;

    public function __construct()
    {
        $this->image = new EmbeddedFile();
    }

    public function getId(): ?int
    {
        return $this->id;
    }

    public function setImageFile(?File $imageFile = null)
    {
        $this->imageFile = $imageFile;

        if (null !== $imageFile) {
            // It is required that at least one field changes if you are using doctrine
            // otherwise the event listeners won't be called and the file is lost
            $this->updatedAt = new \DateTimeImmutable();
        }
    }

    public function getImageFile(): ?File
    {
        return $this->imageFile;
    }

    public function setImage(EmbeddedFile $image)
    {
        $this->image = $image;
    }

    public function getImage(): ?EmbeddedFile
    {
        return $this->image;
    }


}

Answer 1

Override the serialization of User as it is used for security
In general, the simplest solution:

public function __serialize(): array
    {
        return [
            'id' => $this->id,
            'email' => $this->email,
            //......
        ];
    }

public function __unserialize(array $serialized): User
{
    $this->id = $serialized['id'];
    $this->email = $serialized['email'];
    // .....
    return $this;
}