README

Me trying to create a Symfony bundle for rva-vzw/krakboem

(c) Johan Vervloet 2023, 2024

Licensed under AGPL v3 or later

This bundle tries to provide a Symfony implementation of the interfaces for event sourcing I created in rva-vzw/krakboem.

I use symfony messenger for the buses, and doctrine for the event store. (Which is probably not optimal. But it will do for now.) I tried to move normalization to the bundle as well, but I didn't succeed (yet?)

If you install the bundle, it will set up the service container for you. But since I didn't find out yet how to configure doctrine and messenger in a bundle, that's something that needs to be done manually.

There's little documentation for this (experimental) bundle. But you might want to take a look how the projects below use it:

• dikdikdik, my famous app to keep track of the score of the solo whist card game.
• wdebelek, a web app to play card games. We used it in Covid times.
• 1jg, another score app.

Warning!

krakboem-bundle is not compatible anymore with the new eversion of rva-vzw/krakboem I am working on right now. I'm not sure if it will be in the future.

Installation instructions

composer require rva-vzw/krakboem-bundle

Configuration

messenger

The configuration of the buses:

# config/packages/messenger.yaml

framework:
  messenger:
    default_bus: messenger.bus.commands
    buses:
      messenger.bus.events:
        default_middleware: allow_no_handlers
        middleware:
          - 'RvaVzw\KrakBoemBundle\Messenger\EventStoreMiddleware'
      messenger.bus.commands:
      messenger.bus.replay:
        default_middleware: allow_no_handlers

You also need to tag your listeners, so that the correct bus handles the correct messages:

# config/services.yaml:

services:
  _instanceof:
    RvaVzw\KrakBoem\EventSourcing\EventListener\EventListener:
      tags: [{ name: messenger.message_handler, bus: messenger.bus.events }]
    RvaVzw\KrakBoem\EventSourcing\Replay\Replayable:
      tags: [{ name: messenger.message_handler, bus: messenger.bus.replay }]
    RvaVzw\KrakBoem\Cqrs\CommandBus\CommandHandler:
      tags: [{ name: messenger.message_handler, bus: messenger.bus.commands }]

doctrine

Regarding doctrine, I usually configure two entity managers: one for the event store, and one for the read model. This is the configuration I use for krakboem:

# config/packages/doctrine.yaml:

doctrine:
  dbal:
    url: '%env(resolve:DATABASE_URL)%'

    # IMPORTANT: You MUST configure your server version,
    # either here or in the DATABASE_URL env var (see .env file)
    #server_version: '15'
  orm:
    auto_generate_proxy_classes: true
    default_entity_manager: read_model
    proxy_dir: '%kernel.build_dir%/doctrine/orm/Proxies'
    entity_managers:
      read_model:
        naming_strategy: doctrine.orm.naming_strategy.underscore
        auto_mapping: true
        connection: default
        mappings:
          ReadModel:
            is_bundle: false
            dir: '%kernel.project_dir%/src/Infrastructure/ReadModel'
            prefix: 'App\Infrastructure\ReadModel'
            alias: ReadModel
      event_store:
        naming_strategy: doctrine.orm.naming_strategy.underscore
        connection: default
        mappings:
          EventStore:
            is_bundle: false
            type: attribute
            dir: '%kernel.project_dir%/vendor/rva-vzw/krakboem-bundle/src/Doctrine'
            prefix: 'RvaVzw\KrakBoemBundle\Doctrine'
            alias: EventStore