Messenger not working if using processor on same resource

[DurandA]

API Platform version(s) affected: 3.1

Description
When a resource use both the messenger and a custom processor, either the messages are not created if using messenger=true, or the processor is not called if using messenger='input'.

How to reproduce

#[ORM\Entity]
#[ApiResource(
    operations: [
        new Post(
            processor: MyEntityProcessor::class,
            messenger: 'input',
            deserialize: false, 
        )
    ]
)]
class MyEntity
{
}

final class MyEntityProcessor implements ProcessorInterface
{
    public function __construct(private ProcessorInterface $persistProcessor)
    {
    }

    public function process($data, Operation $operation, array $uriVariables = [], array $context = [])
    {
        $result = $this->persistProcessor->process($data, $operation, $uriVariables, $context);
        return $result;
    }
}

services.yaml

services:
    App\State\MyEntityProcessor:
        bind:
            $persistProcessor: '@api_platform.doctrine.orm.state.item_provider'

messenger.yaml

framework:
    messenger:
        transports:
            async: 'doctrine://default'

        routing:
            'App\Entity\MyEntity': async

Additional Context
I need to generate thumbnails on MediaObjects after creation. I want to use Symfony Messenger to trigger this and do it asynchronously since it could take time some to process.

The processor is used to persists the entity. As described in Symfony Messenger Integration:

Note: when using messenger=true ApiResource attribute in a Doctrine entity, the Doctrine Processor is not called. If you want the Doctrine Processor to be called, you should decorate a built-in state processor and implement your own logic.

[soyuka]

decorate the Messenger processor...

[DurandA]

@soyuka You mean something like this in the message handler?

final class MyEntityHandler implements MessageHandlerInterface
{

    public function __construct(private ProcessorInterface $persistProcessor)
    {
    }

    public function __invoke(MediaObject $mediaObject)
    {
        // call $this->persistProcessor->process()
    }
}

The problem with this solution is that the messenger will not be called immediately if it is asynchronous. I need a processor that is called immediately and a message handler that is called asynchronously since it could take several seconds to execute.

[darthf1]

Can you not dispatch an event through the message bus, after the entity is persisted? The event handler can dispatch the GenerateThumbnailCommand, or just execute your logic in the event handler.