[Service Container] The AutowireCallable attribute does not work

[lkolndeep]

Hello Folks,

I tried to use in an example the AutowireCallable attribute:
https://symfony.com/doc/6.4/service_container.html#generating-adapters-for-functional-interfaces

Here, my code:

The interface:

interface MessageFormatterInterface
{
    public function format(string $message, array $parameters): string;
}

My service:

class MessageUtils
{
    public function format(string $message, array $parameters): string
    {
        $stringParam = '';
        if (count($parameters) > 0) {
            foreach($parameters as $element)
                $stringParam .= $element . ', ';
        }

        return strtoupper($message) . ' ' . $stringParam;
    }
}

My method in a controller:

#[Route('/service/message-utils', name: 'app_service_message_utils')]
public function messageUtils(MessageFormatterInterface $formatter): Response
{
    $formattedMessage = $formatter->format('Hello my friends!', ['parameter1', 'parameter2', 'parameter3', 'parameter4']);
    dd($formattedMessage);

    return new Response('Message Utils');
}

When I try this, an error occurs:

Cannot autowire argument $formatter of "App\Controller\ServiceController::messageUtils()": it references interface "App\Service\MessageFormatterInterface" but no such service exists. Did you create a class that implements this interface?

When I add the implements on the MessageUtils service:

class MessageUtils implements MessageFormatterInterface
{
    public function format(string $message, array $parameters): string
    {
        $stringParam = '';
        if (count($parameters) > 0) {
            foreach($parameters as $element)
                $stringParam .= $element . ', ';
        }

        return strtoupper($message) . ' ' . $stringParam;
    }
}

the AutowireCallable attribute works well and the dd($formattedMessage); in the controller gives me this:
"HELLO MY FRIENDS! parameter1, parameter2, parameter3, parameter4, "

Regards,

[lkolndeep]

Hello Folks,

It was not an error.

Actually, I did not use well the attribute.

Here, my updated code:

The interface:

interface MessageFormatterInterface
{
    public function format(string $message, array $parameters): string;
}

My service:

class MessageUtils
{
    public function format(string $message, array $parameters): string
    {
        $stringParam = '';
        if (count($parameters) > 0) {
            foreach($parameters as $element)
                $stringParam .= $element . ', ';
        }

        return strtoupper($message) . ' ' . $stringParam;
    }
}

The Mailer Service:

class Mailer
{
    public function __construct(
        #[AutowireCallable(service: MessageUtils::class, method: 'format')]
        private MessageFormatterInterface $formatter,
    ) {  
    }

    public function send(string $message, array $parameters)
    {
        $formattedMessage = $this->formatter->format($message, $parameters);
        dd($formattedMessage);
    }
}

My method in a controller:

#[Route('/service/message-utils', name: 'app_service_message_utils')]
public function messageUtils(Mailer $mailer): Response
{
    $formattedMessage = $mailer->send('Hello my friends!', ['parameter1', 'parameter2', 'parameter3', 'parameter4']);
    dd($formattedMessage);

    return new Response('Message Utils');
}

When I test it without the implement it works well!