index.md

Streak PHP Event Sourcing Framework

Welcome to the documentation for Streak, a PHP framework designed for building applications using the Event Sourcing pattern.

Philosophy

Streak aims to provide a flexible and robust foundation for event-sourced applications by focusing on:

• Domain-Driven Design (DDD): Encouraging the use of core DDD concepts like Aggregates, Entities, Value Objects, and Domain Events.
• Simplicity: Offering clear interfaces and components that are easy to understand and use.
• Extensibility: Allowing developers to swap out implementations (e.g., Event Store persistence) to fit their specific needs.
• Testability: Making it easy to unit test domain logic and application services.

Core Concepts

Streak is built around several key concepts central to Event Sourcing and DDD:

• Architecture: The foundational patterns and building blocks that form the system.
• Commands: Represent an intention to change the state of the system.
• Events: Represent facts about things that have happened in the past.
• Event Store: Responsible for persisting and retrieving streams of events.
• Event Bus: Allows decoupled components to react to published events.
• Listeners: Components that react to events and trigger side effects.
• Subscriptions: Persistent, reliable mechanism for delivering events to listeners, with support for tracking, restarting, and pausing event processing.

Getting Started

1. Explore Core Concepts: Understand the fundamental building blocks of Streak.
   • Architecture
   • Commands
   • Events
   • Event Store
   • Event Bus
   • Event Listeners
   • Subscription System
   • Testing
2. Symfony Integration (Optional): If you are using Symfony, learn how the StreakBundle simplifies integration.
   • StreakBundle Installation
   • Bundle Configuration
   • Service Registration
   • Console Commands
3. Tutorials: Follow step-by-step guides to build key components of an event-sourced application.
   • Building an Aggregate - Create the core domain model with commands and events
   • Building a Saga - Handle cross-aggregate coordination with external systems
   • Building a Process Manager - Manage complex workflows with state
   • Building a Projection - Create read models optimized for querying

Installation

Installation typically involves using Composer.

composer require streak/streak

For integration with Symfony, you will also need the bundle:

composer require streak/streak-bundle

Refer to the specific StreakBundle Installation guide for more details.

Advanced Topics

After completing the basic tutorials, you might want to explore:

• Event Sourced Subscriptions - Subscription State Persistence
• Custom Event Store Implementations - Adapting to different storage backends
• Projection Performance Optimization - For high-volume event streams

Contributing

Contributions to Streak are welcome! Please follow the Documentation Style Guide when adding or updating documentation.