README

Universal Service Provider for Gember Event Sourcing , compatible with any application or framework that supports container-interop/service-provider.

Installation

Install the service provider with composer:

composer require gember/event-sourcing-universal-service-provider

Configuration

This package installs Gember Event Sourcing with all required dependency adapters. Some of these adapters need to be configured.

By default, it uses the following configuration:

PSR-11 Container definition (https://www.php-fig.org/psr/psr-11):

use Doctrine\DBAL\Connection;
use Gember\IdentityGeneratorSymfony\Ulid\SymfonyUuidIdentityGenerator;
use Psr\Container\ContainerInterface;
use Symfony\Component\Serializer\Serializer;

return [
    'gember_event_sourcing' => fn(ContainerInterface $container) => [
        'message_bus' => [
            'symfony' => [
                'event_bus' => $container->get('event.bus'),
            ],
        ],
        'cache' => [
            'enabled' => false,
            // set a PSR-6 or PSR-16 implementation
            // 'psr16' => $container->get('cache.file'),
            // 'psr6' => $container->get('cache.file'),
        ],
        'serializer' => [
            'symfony' => [
                'serializer' => $container->get(Serializer::class),
            ],
        ],
        'event_store' => [
            'rdbms' => [
                'doctrine_dbal' => [
                    'connection' => $container->get(Connection::class),
                ],
            ],
        ],
        'generator' => [
            'identity' => [
                'service' => $container->get(SymfonyUuidIdentityGenerator::class),
                // or use ULIDs
                // 'service' => $container->get(SymfonyUlidIdentityGenerator::class),
            ],
        ],
        'registry' => [
            'event' => [
                'reflector' => [
                    'path' => '/path/to/src',
                    // default: getcwd() . '/../src'
                ],
            ],
            'command_handler' => [
                'reflector' => [
                    'path' => '/path/to/src',
                    // default: getcwd() . '/../src'
                ],
            ],
        ],
    ],
];

You can override any of these defaults however you like.

Required dependencies

Some of the required dependencies also need to be configured separately.

Symfony Messenger (symfony/messenger)

The default configuration makes use of a service with name event.bus.

When this bus is configured, Gember Event Sourcing works out of the box. However, when a different event bus is preferred, it must be a service implementing Symfony\Component\Messenger\MessageBusInterface.

Example (minimum) configuration for symfony/messenger:

PSR-11 Container definition (https://www.php-fig.org/psr/psr-11):

use Psr\Container\ContainerInterface;
use Symfony\Component\Messenger\Handler\HandlerDescriptor;
use Symfony\Component\Messenger\Handler\HandlersLocator;
use Symfony\Component\Messenger\MessageBus;
use Symfony\Component\Messenger\Middleware\HandleMessageMiddleware;

return [
    'event.bus' => fn(ContainerInterface $container) => new MessageBus([
        new HandleMessageMiddleware(new HandlersLocator([
            // Ideally this could be autoconfigured
            SomeDomainEvent::class => [
                new HandlerDescriptor([
                    $container->get(SomeProjector::class), 
                    'onSomeDomainEvent'
                ]),
            ],
        ]), allowNoHandlers: true),
    ]),
];

Symfony Cache (symfony/cache)

The default configuration makes use of a service with name cache.file.

When this cache service is configured, Gember Event Sourcing works out of the box. However, when a different cache pool is preferred, it must be a service implementing Psr\Cache\CacheItemPoolInterface (PSR-6) or Psr\SimpleCache\CacheInterface (PSR-16).

Example (minimum) configuration for symfony/cache:

PSR-11 Container definition (https://www.php-fig.org/psr/psr-11):

use Symfony\Component\Cache\Adapter\FilesystemAdapter;
use Symfony\Component\Cache\Psr16Cache;

return [
    'cache.file' => fn() => new Psr16Cache(new FilesystemAdapter(
        directory: __DIR__ . '/../../var/cache',
    )),
];

Symfony Serializer (symfony/serializer)

The default configuration makes use of a service with name Symfony\Component\Serializer\Serializer.

When this serializer service is configured, Gember Event Sourcing works out of the box. However, when a different serializer is preferred, it must be a service implementing Symfony\Component\Serializer\SerializerInterface.

Example (minimum) configuration for symfony/serializer:

PSR-11 Container definition (https://www.php-fig.org/psr/psr-11):

use Symfony\Component\Serializer\Encoder\JsonEncoder;
use Symfony\Component\Serializer\Normalizer\DateTimeNormalizer;
use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
use Symfony\Component\Serializer\Serializer;

return [
    Serializer::class => fn() => new Serializer([
        new DateTimeNormalizer([
            DateTimeNormalizer::FORMAT_KEY => 'Y-m-d\TH:i:s.uP',
        ]),
        new ObjectNormalizer(),
    ], [
        new JsonEncoder(),
    ]),
];

Doctrine DBAL/ORM (doctrine/dbal, doctrine/orm)

The default configuration makes use of a service with name Doctrine\DBAL\Connection.

When this connection service is configured, Gember Event Sourcing works out of the box. However, when a different Doctrine connection is preferred, it must be a service implementing Doctrine\DBAL\Connection.

Example (minimum) configuration for doctrine/dbal:

PSR-11 Container definition (https://www.php-fig.org/psr/psr-11):

use Doctrine\DBAL\Connection;
use Doctrine\DBAL\DriverManager;

return [
    Connection::class => fn() => DriverManager::getConnection([
        'host' => $_ENV['DB_HOST'],
        'port' => $_ENV['DB_PORT'],
        'dbname' => $_ENV['DB_DBNAME'],
        'user' => $_ENV['DB_USER'],
        'password' => $_ENV['DB_PASSWORD'],
        'driver' => $_ENV['DB_DRIVER'],
        'charset' => $_ENV['DB_CHARSET'],
    ]),
];

Database

In order to persist all domain events in database, a running SQL database is needed. The event store requires two tables. Schema is available in either raw SQL or in a migration file format:

Raw SQL schema: https://github.com/GemberPHP/rdbms-event-store-doctrine-dbal/blob/main/resources/schema.sql

Migrations:

• Doctrine migrations: https://github.com/GemberPHP/rdbms-event-store-doctrine-dbal/blob/main/resources/migrations/doctrine
• Phinx migrations: https://github.com/GemberPHP/rdbms-event-store-doctrine-dbal/tree/main/resources/migrations/phinx

Good to go!

Check the main package gember/event-sourcing or the demo application gember/example-event-sourcing-dcb for examples.