Clean Architecture isn't just a buzzword; it's a structural necessity for scalable mobile applications. In this guide, we dive deep into how to organize your Flutter projects to ensure they remain testable, maintainable, and independent of external frameworks.
The Core Principles
At its heart, Clean Architecture is about separation of concerns. The code is divided into layers, with a strict dependency rule: inner layers should not know anything about outer layers.
Layer Breakdown
Most Flutter implementations of Clean Architecture involve three primary layers: Data, Domain, and Presentation.
1. Domain Layer
The Domain layer contains entities, use cases, and repository interfaces. This is where your business logic lives, untouched by UI or database implementations.
2. Data Layer
The Data layer implements repository interfaces defined in the Domain layer, handling API network requests, local SQLite/Hive caching, and data mapping.
3. Presentation Layer
The Presentation layer houses UI widgets and state management controllers (BLoC / Cubit / Provider).