Symfony 4 API Rest PUT : Map data to database entity - api

Question

I'm a begginer in Symfony 4 and I'm developing an API Rest. I want to create a PUT resource that can handle many update cases.
In my case, I have a user with many properties but I will take an example with 3 properties to keep things simple :
User {
username,
email,
password
}
My PUT resource can be called in order to update Username, update Email or update Password. For example, to update Username, the user of my API will send a PUT request with only username :
{
username: "New username"
}
Same for email and password, he will only send the property he wants to change.
My problem is in my Controller, I have to do things like this :
/**
* #Rest\Put("/user/{id}")
* #param Request $request
* #return View
*/
public function putUserRequest(Request $request)
{
$userId = $request->get('id');
$user = $this->doctrine->getRepository(User::class)->findOneBy('id' => $userId);
$userFromRequest = $this->serializer->deserialize($request->getContent(), User::class, 'json');
if ($userFromRequest->getUsername() != NULL) {
$user->setUsername($userFromRequest->getUsername())
}
if ($userFromRequest->getEmail() != NULL) {
$user->setEmail($userFromRequest->getEmail())
}
if ($userFromRequest->getPassword() != NULL) {
$user->setPassword($userFromRequest->getPassword())
}
// ...
}
In my example I have only 3 properties, but imagine when I have 30 properties.
With Symfony 3 I used forms to validate / save my datas :
$form->submit($request->request->all(), $clearMissing);
Where $clearMissing is false to keep datas not provided by the user of my API. I can't find a way to do it with serializer but I guess I'm doing things wrong.
Thanks.

Answer 1

If I understand correctly, You can use the validator Component like this :
/**
* #Rest\Put("/user/{id}")
* #param Request $request
* #return View
*/
public function putUserRequest(User $user, Request $request, ValidatorInterface $validator)
{
$data = $request->getContent();
$this->serializer->deserialize($data, User::class, 'json', ['object_to_populate' => $user]);
//At this moment, the data you sent is merged with your user entity
/** #var ConstraintViolationList $errors */
$errors = $validator->validate($user, null ,['groups' => 'user_update']);
if (count($errors) > 0) {
//return json reponse with formated errors;
}
//if ok $entityManager->flush() and Response Json with serialization group;
...
}
In your user class :
class User implements UserInterface
{
/**
* #Assert\Email(groups={"user_create", "user_update"})
*/
private $email;
/**
* #Assert\NotBlank(groups={"user_create", "user_update"})
* #Assert\Length(min=7, groups={"user_create", "user_update"})
*/
private $password;
/**
* #Assert\Length(min=2, groups={"user_create", "user_update"} )
*/
private $username;
}
Related Validator component documentation : https://symfony.com/doc/current/validation/groups.html
You can also check this project : https://github.com/attineos/relation-deserializer