Symfony API : test if the content has the keys - symfony

Question

With Symfony, I can get the content of request (POST and application/json) with :
$content = json_decode($request->getContent());
dd($content) return :
[
"subject" => "test"
"content" => "content"
]
I just want to hydrate an object with the subject, this works good :
$subject = new SubjectEntity();
$subject->setSubject($content['subject]);
But I don't want to do a setSubject() if the subject key doesn't exist.
I know I can do an if for each variable (Or $subject->setSubject($content['subject] ?? null)), but I think it will be a bit tedious in more complex cases.
Is there a way to "validate" the content sent to verify that all the desired keys are present ?

Answer 1

The cleanest solution would be a request param validator using symfony validator
Example:
public function validateRequest(array $params): array
{
$validator = Validation::createValidator();
$constraints = new Assert\Collection([
'subject' => new Assert\Type('string'),
'content' => new Assert\Type('string'),
]);
$group = new Assert\GroupSequence(['Default', 'custom']);
return $validator->validate($params, $constraints, );
}
If the keys can be optional, then you must use Assert\Optional(). Either way, you will need the null coalescing operator to cast to null if the key isn't set.
You can put these in a different class and with a small refactor you can make it work much nicer than doing a bunch of ifs, and it can be re-used to validate all of your api requests.