TYPO3 CMS Event Sourcing Bundle

In a nutshell

• https://www.slideshare.net/slideshow/typo3-event-sourcing/68245192 (TYPO3camp Rhein-Ruhr, 2016)
• the database table sys_event_store contains all event streams for any record
• multiple database connections are maintained automatically (using Doctrine DBAL)
  • "Origin": this is basically the plain source, as we still know it in 2024; in the scope of event-sourcing it is NOT to be used anymore
  • "Default": these are all events projected (materialized) into a SQL database; modifications usually should happen via commands, events, etc. - this is the "compatibility layer" for the SQL world know - direct modifying SQL operations (update, delete, insert) are intercepted and transformed into events automatically
  • "LocalStorage::workspace-0: this is an independent, automatically projected context for a particular workspace, it does not contain any workspace overlays anymore, just the materialized entities for that particular workspace
• \TYPO3\CMS\DataHandling\DataHandling\Interceptor\Hook\Backend\DataHandlerHook and \TYPO3\CMS\DataHandling\Core\Compatibility\DataHandling\DataHandlerTranslator are doing all the magic, turning the legacy DataHandler data structures into commands, aggregates and finally events

Installation

Configure your web-server to point to directory ./eventsourcing-bundle/www/. All other requirements for installing TYPO3 CMS have to be fulfilled for the infrastructure as well.

Clone this repository & install

git clone git@github.com:TYPO3Incubator/eventsourcing-bundle.git
cd eventsourcing-bundle

ddev start
ddev import-db -f .ddev/db.sql.gz

A new TYPO3 instance is being installed using the TYPO3 console. Besides that the extensions version, workspaces, bootstrap_package, introduction, event_sourcing and data_handling are installed

Upgrade schema & events

Open the Install Tool and

• execute compare current database with specification in the important actions section, create all new t3uuid and t3rev fields
• execute initialize events for existing records in the upgrade wizard section, wait until all events for existing records have been determined
  • this could take some time

Bank Account Example

In addition you can enable the bank_account_example, create a new page and put the accordant frontend pluging for the bank account example on that page.

Infrastructure

• events are stored in the MySQL table sys_event_store
• additional SQLite databases are created in typo3temp/var/LocalStorage/