Outbox Installation & Configuration

To use the transactional outbox pattern to publish your events on the event bus, there are additional steps you need to take.

warning

These steps are optional, and only necessary if you want to use the AsPublishedDomainEventListener strategy.

Installation

Make sure Composer is installed globally, as explained in the installation chapter of the Composer documentation.

With Symfony Flex

Open a command console, enter your project directory and execute:

composer require rekalogika/domain-event-outbox

Without Symfony Flex

Step 1: Download the Bundle

Open a command console, enter your project directory, and execute the following command to download the latest stable version of this bundle:

composer require rekalogika/domain-event-outbox

Step 2: Enable the Bundle

Then, enable the bundle by adding it to the list of registered bundles in the config/bundles.php file of your project:

config/bundles.php

return [
    // ...
    Rekalogika\DomainEvent\Outbox\RekalogikaDomainEventOutboxBundle::class => ['all' => true],
];

Symfony Messenger Configuration

The package requires a Symfony Messenger bus named rekalogika.domain_event.bus. You can accomplish that by creating the configuration file:

config/packages/rekalogika_domain_event_outbox.yaml

framework:
    messenger:
        buses:
            rekalogika.domain_event.bus:
                default_middleware:
                    allow_no_handlers: true

Make Sure the Default messenger.yaml Has an Explicit Bus Configuration

danger

The default Symfony Messenger configuration does not define buses and default_bus. You need to make sure they are present in your configuration file. Otherwise, our bus configuration above will silently become the default bus.

config/packages/messenger.yaml

# default messenger.yaml with explicit default bus

framework:
    messenger:
        failure_transport: failed

        transports:
            # https://symfony.com/doc/current/messenger.html#transport-configuration
            async:
                dsn: '%env(MESSENGER_TRANSPORT_DSN)%'
                options:
                    use_notify: true
                    check_delayed_interval: 60000
                retry_strategy:
                    max_retries: 3
                    multiplier: 2
            failed: 'doctrine://default?queue_name=failed'
            # sync: 'sync://'

        ### You need to add this
        ### START
        default_bus: messenger.bus.default

        buses:
            messenger.bus.default: null
        ### END

        routing:
            Symfony\Component\Mailer\Messenger\SendEmailMessage: async
            Symfony\Component\Notifier\Message\ChatMessage: async
            Symfony\Component\Notifier\Message\SmsMessage: async

            # Route your messages to the transports
            # 'App\Message\YourMessage': async

Configure Your Domain Events Routing

With this package, your domain events become the message classes of the Symfony Messenger. And like other Symfony Messenger messages, you may need to configure the routing for your domain events. You can do that like the following.

config/packages/messenger.yaml

framework:
    messenger:
        # ...
        routing:
            # ...
            'Rekalogika\DomainEvent\Outbox\Message\MessageRelayStartMessage': async
            'App\DomainEvent\*': async

Bundle Configuration

The bundle defines the following configuration option:

config/packages/rekalogika_domain_event_outbox.yaml

rekalogika_domain_event_outbox:
    # The name of database table used to store the outgoing messages
    outbox_table: rekalogika_event_outbox