message-bus

v2

Requirements

  • PHP ~8.4.1 || ~8.5.0

  • A PSR-11 container. This library is developed and tested against laminas/laminas-servicemanager (^4.0.0), but any PSR-11 implementation works.

Installation

composer require webware/message-bus

The package registers Webware\MessageBus\ConfigProvider via composer's extra.laminas.config-provider, so it's auto-discovered by Laminas\ConfigAggregator\ConfigAggregator (and therefore by Mezzio). No manual config file is needed.

If you're not using ConfigAggregator, merge the provider's output into your own configuration manually:

$config = array_merge_recursive(
    (new Webware\MessageBus\ConfigProvider())(),
    /* ...your application config... */
);

What gets registered

ConfigProvider wires up the following services (see Configuration & Container Integration for details):

  • MessageBusInterface -> MessageBus

  • MiddlewarePipelineInterface -> MiddlewarePipe

  • MessageHandlerResolverInterface -> MessageHandlerResolver

  • StrategyInterface -> Strategy\HandleStrategy (the default; alias it to Strategy\ClassnameStrategy to opt into named handler methods)

  • Middleware\MessageHandlerMiddleware (registered in the pipeline by default, at the lowest priority so it runs last)

None of this does anything useful yet, though. You still need to:

  1. Define a command or query (implementing Command\CommandInterface or Query\QueryInterface).

  2. Define its handler (implementing CommandHandlerInterface or QueryHandlerInterface). These are marker interfaces with no required method; declare the method your wired strategy expects (handle() under the default strategy).

  3. Map the message class to the handler class, and register the handler in your container.

See Usage Examples for a complete walk-through.

Dispatching your first message

Once a command/handler pair is mapped and registered (see Usage Examples), dispatching is just:

/** @var Psr\Container\ContainerInterface $container */
$bus = $container->get(Webware\MessageBus\MessageBusInterface::class);

$result = $bus->handle(new App\Command\CreateUser('jane@example.com'));

$result->getStatus(); // MessageStatus::Success or ::Failure
$result->getResult(); // whatever the handler returned