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Handler ​

Raxos\MessageBus\Attribute\Handler is a class level attribute that links a message class to the handler that processes it. It is the one piece of wiring the bus needs: at consume time the queue reads this attribute from the message class through reflection to find the right handler.

php
#[Attribute(Attribute::TARGET_CLASS)]
final readonly class Handler

Constructor ​

php
public function __construct(
    string $handlerClass
)

Takes a single class-string pointing at a Raxos\Contract\MessageBus\HandlerInterface implementation. The value is stored on the public handlerClass property.

Usage ​

Apply the attribute once, at the class level, on the message.

php
<?php
declare(strict_types=1);

namespace App\MessageBus;

use Raxos\Contract\MessageBus\MessageInterface;
use Raxos\MessageBus\Attribute\Handler;

#[Handler(SendWelcomeEmailMessageHandler::class)]
final readonly class SendWelcomeEmailMessage implements MessageInterface
{
    public function __construct(
        public string $userId
    ) {}

    public function __serialize(): array
    {
        return [$this->userId];
    }

    public function __unserialize(array $data): void
    {
        $this->userId = $data[0];
    }
}

If a message is consumed without a Handler attribute, MessageBusQueue::consume() throws a MessageBusMissingHandlerException.

See also ​