Examples

These examples show how to write an event sourced application, with and without classes in this library.

In the first section, a stand-alone event sourced domain model is developed which has no dependencies on the library, along with an application object that has minimal dependencies on library infrastructure classes for storing events. In later sections, more use is made of library classes, in order to demonstrate the other capabilities of the library.

All the examples in this guide follow the layered architecture: application, domain, infrastructure. To create working programs, simply copy all the code snippets from a section into a Python file.

Please feel free to experiment by making variations. The code snippets in this guide are covered by a test case, so please expect everything to work as presented - raise an issue if something goes wrong.

Contents

• Example application
  • Domain
  • Infrastructure
  • Application
  • Run the code
• Snapshotting
  • Domain
  • Infrastructure
  • Application
  • Run the code
• Aggregates in DDD
  • Aggregate root
  • Application and infrastructure
  • Run the code
• Application-level encryption
  • Cipher strategy
  • Application and infrastructure
  • Run the code
• Optimistic concurrency control
  • Application and infrastructure
  • Run the code
  • Cassandra
• Alternative schema
  • Stored event model
  • Applause djangoevents project
• Using Cassandra
  • Infrastructure
  • Application object
  • Run the code
• Everything in one app
  • Domain
  • Infrastructure
  • Application
  • Run the code
• Projections and notifications
  • Synchronous update
  • Asynchronous update
  • Application log
  • Notification log
• Deployment
  • Application object
  • Database connection
  • Web interfaces
  • Task queues