Custom operation identifier has a different type from the entity's one but gets normalized with the entity's identifier type.

[blesenechal]

I have a GET operation that retrieves an item based on a unique parameter which is a string.
It works fine with 2.2.9, but not with 2.3.0.

It looks like the query parameter value is casted to an int somewhere.

==================================

Example with the api-platform/demo project, to get the books by ISBN

1 - I create a custom operation with "requirements" (as defined in https://api-platform.com/docs/core/operations) :

 * @ApiResource(
 *     itemOperations={
 *         "get"={"method"="GET", "path"="/books/{id}"},
 *         "get_by_isbn"={"method"="GET", "path"="/books/by_isbn/{id}", "requirements"={"id"=".+"}},
 *     }
 * )

2 - I create a data provider :

namespace App\DataProvider;

use ApiPlatform\Core\DataProvider\ItemDataProviderInterface;
use ApiPlatform\Core\DataProvider\RestrictedDataProviderInterface;
use ApiPlatform\Core\Exception\ResourceClassNotSupportedException;
use App\Entity\Book;
use Doctrine\ORM\EntityManagerInterface;

final class BookIsbnItemDataProvider implements ItemDataProviderInterface, RestrictedDataProviderInterface
{
    private $entityManager;

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

    public function supports(string $resourceClass, string $operationName = null, array $context = []): bool
    {
        return (Book::class === $resourceClass) && ('get_by_isbn' === $operationName);
    }

    public function getItem(string $resourceClass, $identifiers, string $operationName = null, array $context = []): ?BlogPost
    {
        return $this->entityManager->getRepository(Book::class)->findOneBy(['isbn' => $identifiers]);
    }
}

3 - When executing the request GET /books/by_isbn/plop :

• With 2.2.9 : In getItem, $identifiers is 'plop' (string)
• With 2.3.0 : In getItem, $identifiers is 0 (int)

[soyuka]

In your parameter route {$id} has the type of your resource class $id property, which is an integer. Because of this it will go through the identifier IntegerDenormalizer and transform your string to a number.
I'm not sure that renaming the identifier would work because of:

core/src/DataProvider/OperationDataProviderTrait.php

Line 89 in 0df2069

if (!isset($parameters['id'])) {

There isn't a good solution for now but I'm looking for one. In the mean time I'd recommend to set _api_receive to false (avoids the ReadListener) and use your own controller that calls the data provider.
You could also use a subresource custom collection instead but that's not easy to set up...

Can you tell me if isbn is a property of your book?

---

Side note:
You could implement the DenormalizedIdentifiersAwareItemDataProviderInterface. The $identifiers will then be an array.

[blesenechal]

Thanks for your response.

Note: with your suggestion of using DenormalizedIdentifiersAwareItemDataProviderInterface, $identifiers is an array but still casted to an int:

array(1) {
  ["id"]=>
  int(0)
}

[soyuka]

Yes I know but it's good to implement that because my fix will probably need it :).

Can you tell me if isbn is a property of your book?

[blesenechal]

Yes, isbn is a property of the book (I used the demo project as reproducer)

[soullivaneuh]

You can start a quickfix using is_numeric instead of is_string inside the IntegerDenormalizer::support method.

[Simperfit]

This should be considered as a BC Break cc @dunglas.