[Serializer] Extract types of constructor parameters from docblock comment

[sergeyfedotov]

Q	A
Bug report?	no
Feature request?	yes
BC Break report?	no
RFC?	no
Symfony version	?

Currenly PhpDocExtractor works only with class properties. It's not possible to clarify the type of the constructor parameter through docblock comment.

class A
{
    private $b;

    /**
     * @param B[] $b
     */
    public function __construct(array $b)
    {
        $this->b = $b;
    }

    public function getB()
    {
        return $this->b;
    }
}

class B
{
    private $c;

    public function __construct($c)
    {
        $this->c = $c;
    }

    public function getC()
    {
        return $this->c;
    }
}

$a = $serializer->denormalize(['b' => [['c' => 1], ['c' => 2], ['c' => 3]]], A::class);
print_r($a);

Expected result:

App\A Object
(
    [b:App\A:private] => Array
        (
            [0] => App\B Object
                (
                    [c:App\B:private] => 1
                )
            [1] => App\B Object
                (
                    [c:App\B:private] => 2
                )
            [2] => App\B Object
                (
                    [c:App\B:private] => 3
                )
        )
)

Actual result:

App\A Object
(
    [b:App\A:private] => Array
        (
            [0] => Array
                (
                    [c] => 1
                )
            [1] => Array
                (
                    [c] => 2
                )
            [2] => Array
                (
                    [c] => 3
                )
        )
)

[nicolas-grekas]

@lyrixx maybe something you'd like to do since you're in that kind of business these days? :)

[lyrixx]

Ahah, Good try ;)

I'm currently moving an API to api platform and I'm hitting E_TOO_MANY_BUGS (symfony, flex/recipes, api-platform/core and api-platform/docs)

So I'm sorry but I think I will not be able to implement this feature

[xabbuh]

Isn't this related to #25605?

[sergeyfedotov]

@xabbuh AbstractNormalizer already extracts this kind of information through reflection without the PropertyInfo component. It uses the extracted types to instantiate an object. The change proposed in the #25605 doesn't affect the current behaviour.

[Simperfit]

@dunglas any thoughs on how to fix this ?

[dvc]

I found in one normalizer test:

        $extractor = new PropertyInfoExtractor([], [new PhpDocExtractor(), new ReflectionExtractor()]);
        $normalizer = new ObjectNormalizer(null, null, null, $extractor);

Using PhpDocExtractor, activates reading blocks like:

    /**
     * @param B[] $b
     */

It supports after 3.4 (#29513)

Only update documentation required

[piotrooo]

@dvc day-saver thx! :)

[CaliforniaMountainSnake]

Just some link that I was inspired by:
https://medium.com/@rebolon/the-symfony-serializer-a-great-but-complex-component-fbc09baa65a0

My finally serializer that can successfully deserialize nested arrays of objects is:

$extractor = new PropertyInfoExtractor([], [new PhpDocExtractor(), new ReflectionExtractor()]);
$converter = new CamelCaseToSnakeCaseNameConverter();
$normalizers = [
    new DateTimeNormalizer(),
    new ArrayDenormalizer(),
    new ObjectNormalizer(null, $converter, null, $extractor),
];
$encoders = [new JsonEncoder()];
return new Serializer($normalizers, $encoders);