Dynamic Validation Group documentation outdated

[ClementVincent]

The way to use a ValidationGroupsGenerator descirbed in the documentation is no longer valid.
ApiPlatform version : "^2.7"

Old Documentation:

<?php
// api/src/Entity/Book.php
namespace App\Entity;

use ApiPlatform\Metadata\ApiResource;
use App\Validator\AdminGroupsGenerator;
use Symfony\Component\Validator\Constraints as Assert;

#[ApiResource(validationContext: ['groups' => [AdminGroupsGenerator::class]])
class Book
{
    #[Assert\NotBlank(groups: ['a'])] 
    public $name;

    #[Assert\NotNull(groups: ['b'])] 
    public $author;

    // ...

New way:

<?php
// api/src/Entity/Book.php
namespace App\Entity;

use ApiPlatform\Metadata\ApiResource;
use App\Validator\AdminGroupsGenerator;
use Symfony\Component\Validator\Constraints as Assert;

// ----------------Changes are here --------------------
#[ApiResource(validationContext: ['groups' => AdminGroupsGenerator::class])
// ----------------Changes are here --------------------
class Book
{
    #[Assert\NotBlank(groups: ['a'])] 
    public $name;

    #[Assert\NotNull(groups: ['b'])] 
    public $author;

    // ...

Doing otherwise will result on ApiPlatform not to invoke the AdminGroupsGenerator::class but use its fully qualified class name instead as a validation group (see Validator code bellow)

// ApiPlatform\Symfony\Validator\Validator

    // ...

    public function validate($data, array $context = [])
    {
        if (null !== $validationGroups = $context['groups'] ?? null) {
            if (
                $this->container &&
                \is_string($validationGroups) &&
                $this->container->has($validationGroups) &&
                ($service = $this->container->get($validationGroups)) &&
                \is_callable($service)
            ) {
            // ...
        }
        // ...
    }

// Old documentation : 
\is_string($validationGroups) // false, because $validationGroups is array
// New documentation : 
\is_string($validationGroups) // true, because $validationGroups is string

[alanpoulain]

Fixed by #1638 thanks.