Not exprexted behaviour on symfony datatransformer - symfony

Question

I created a datatransformer to store dates on unixtime on the database but show it as datetime on the form
this is the transformer
class IntegerToTimestampTransformer implements DataTransformerInterface
{
public function transform($timestamp)
{
/**
* This if sentenceis because when eidt $timestamp is a timestamp(unix)
* but when create is a DateTime ¿¿???
*/
if($timestamp instanceof \DateTime){
return $timestamp;
}
return (new \DateTime())->setTimestamp($timestamp);
}
public function reverseTransform($datetime)
{
if ($datetime === null) {
return $datetime;
}
return $datetime->getTimestamp();
}
}
this is the entity
/**
* Popup
*
* #ORM\Table(name="popup")
* #ORM\Entity(repositoryClass="AppBundle\Repository\PopUpRepository")
*/
class Popup
{
/**
* #var int
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #Gedmo\Translatable()
* #ORM\Column(name="title", type="string", length=255)
*/
private $title;
/**
* #var string
*
* #Gedmo\Translatable()
* #ORM\Column(name="description", type="text")
*/
private $description;
/**
* #var int
*
* #ORM\Column(name="activation_date", type="integer", nullable=true)
*/
private $activationDate;
/**
* #var int
*
* #ORM\Column(name="deactivation_date", type="integer", nullable=true)
*/
private $deactivationDate;
/**
* #var boolean
*
* #ORM\Column(name="active", type="boolean")
*/
private $active;
/**
* #var Collection
*
* #ORM\ManyToMany(targetEntity="AppBundle\Entity\Role")
* #ORM\JoinTable(name="popup_role", joinColumns={#ORM\JoinColumn(name="popup_id", referencedColumnName="id")},
* inverseJoinColumns={#ORM\JoinColumn(name="role_id", referencedColumnName="id")})
*/
private $roles;
public function __construct()
{
$this->roles = new ArrayCollection();
}
/**
* #return int
*/
public function getId(): int
{
return $this->id;
}
/**
* #param int $id
*/
public function setId(int $id): void
{
$this->id = $id;
}
/**
* #return string
*/
public function getTitle():? string
{
return $this->title;
}
/**
* #param string $title
*/
public function setTitle(string $title): void
{
$this->title = $title;
}
/**
* #return string
*/
public function getDescription(): ?string
{
return $this->description;
}
/**
* #param string $description
*/
public function setDescription(string $description): void
{
$this->description = $description;
}
/**
* #return int
*/
public function getActivationDate(): ?int
{
return $this->activationDate;
}
/**
* #param int $activationDate
*/
public function setActivationDate(int $activationDate): void
{
$this->activationDate = $activationDate;
}
/**
* #return int
*/
public function getDeactivationDate(): ?int
{
return $this->deactivationDate;
}
/**
* #param int $deactivationDate
*/
public function setDeactivationDate(int $deactivationDate): void
{
$this->deactivationDate = $deactivationDate;
}
/**
* #return bool
*/
public function isActive(): ?bool
{
return $this->active;
}
/**
* #param bool $active
*/
public function setActive(bool $active): void
{
$this->active = $active;
}
/**
* Add role
*
* #param Role $role
*
* #return Role
*/
public function addRole(Role $role)
{
$this->roles[] = $role;
return $this;
}
/**
* Remove role
*
* #param Role $role
*/
public function removeRole(Role $role)
{
$this->roles->removeElement($role);
}
/**
* Get role
*
* #return Collection
*/
public function getRoles()
{
return $this->roles;
}
}
and the formtype
class PopupType extends AbstractType
{
private $tranformer;
public function __construct(IntegerToTimestampTransformer $tranformer){
$this->tranformer = $tranformer;
}
/**
* {#inheritdoc}
*/
public function buildForm(FormBuilderInterface $builder, array $options)
{
$date_array = [
'label_attr' => [
'class' => 'font-weight-bold'
],
'required' => false
];
if(!$options['edit']){
$date_array['data'] = new \DateTime();
}
$builder
->add('title', TextType::class, [
'label_attr' => [
'class' => 'font-weight-bold'
],
])
->add('description', TextareaType::class, [
'label_attr' => [
'class' => 'font-weight-bold'
],
'required' => false
])
->add('activation_date', DateTimeType::class, $date_array)
->add('deactivation_date', DateTimeType::class,$date_array)
->add('active', CheckboxType::class, [
'label_attr' => [
'class' => 'font-weight-bold'
],
'required' => false
])
->add('roles', EntityType::class, [
'class' => Role::class,
'expanded' => true,
'multiple' => true,
'required' => true,
'label_attr' => [
'class' => 'font-weight-bold'
],
])
;
$builder->get('activation_date')->addModelTransformer($this->tranformer);
$builder->get('deactivation_date')->addModelTransformer($this->tranformer);
}
/**
* {#inheritdoc}
*/
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults(array(
'data_class' => Popup::class,
'edit' => false
));
}
/**
* {#inheritdoc}
*/
public function getBlockPrefix()
{
return 'appbundle_popup';
}
}
I debugged and I checked that in the transform function when I try to create on the crud the parameter passed to transform is a Datetime the there is no need to transformate the data but when I try to edit the parameter passed to transform is a unixtime integer the the transformation is needed, I don't understant that behaviour.