EventSourcing Workshop

In here, you will find a "from scratch" PHP-based implementation of Event-Sourcing, kept to a minimum on purpose, to allow workshop attendees to explore and experiment with its concepts.

DISCLAIMER: Not a production project

This is not a library nor production-ready project: this is an educational project. Its target audience is students and backend engineers that want to get better at abstracting/maintaining business logic.

Knowledge required

To work in this project, you need some rough knowledge about:

• php
  • you should be familiar with php's syntax
  • the provided test suite and tooling should help you prevent mistakes, but you should have basic knowledge of how php runs and fails.
  • we use functional and object-oriented paradigms: you may be up for a crash-course, if you never saw code structured this way.
• composer
  • php class autoloading and dependency installation is handled for you, but if something goes wrong, you should know some composer basics
• sql
  • the entire workshop is based on SQLite databases: it's just files, but you need to know some very basic SQL
• make
  • most repetitive tasks have been added to a Makefile: run make to see what's available
• docker and docker-compose
  • to ensure everyone runs on the same environment, we run tests inside a docker container. Building images and starting/stopping containers is sufficient: we will not use any advanced docker features
  • don't worry too much if you don't: the Makefile should abstract most docker stuff away

Firing it up

Run:

make composer-install
make quality-assurance
make interactive-shell

Architecture

• EventSourcingWorkshop\EventSourcing documentation
• EventSourcingWorkshop\Commanding documentation
• example implementation used in integration tests

---

Exercises

Note: all exercises are under the watchful eye of static analysis and CS tooling. Use make quality-assurance to validate your current work!

1. Standalone recording of a temperature
2. Tracking the last recorded temperature at each location
3. Tracking the average recorded temperature at each location, but in the database
4. Send an alert when the temperature is below freezing point
5. Payment aggregate
6. Collaborative event-sourcing:
   • TODO: idea of mapping a speed-trap fine management process
   • TODO: idea of mapping a hotel reservation + stay process

License

This software is proprietary: please contact the author for permission to use, but for now, these sources are not freely reusable outside educational purposes. Yes: you are reading correctly, this is not MIT/BSD software :-P