Day 89 of 100daysofcode : Understanding Clean Architecture in Flutter🧹
Ever heard of Clean Architecture but unsure how it applies to Flutter? Let’s demystify it!
What is Clean Architecture?
It’s a design pattern that organizes code into layers to separate concerns, making apps more scalable, testable, and maintainable. The core idea: dependencies flow inward, and inner layers don’t depend on outer layers.
The 3 Key Layers
- Presentation Layer (UI)
What: Widgets, state management (e.g., Cubit, Provider), and UI logic.
Why: Handles how data is displayed.
Rule: Never contains business logic!
- Domain Layer (Core Business Logic)
What: Entities (business models), use cases (app features), and repository interfaces.
Why: Defines what the app does, independent of frameworks or data sources.
Rule: Pure Dart—no Flutter dependencies!
- Data Layer (Data Sources)
What: Repositories (implementation), APIs, databases, local storage.
Why: Fetches/stores data (e.g., REST API ↔ Domain).
Rule: Implements interfaces defined in the Domain layer.
How It Fits in Flutter
- Independence: Change your UI (Presentation) or switch databases (Data) without breaking business logic (Domain).
- Testability: Test Domain layer without Flutter dependencies; mock Data layer for UI tests.
- Scalability: Add features or refactor code with minimal ripple effects.
Why You’ll Love It
Future-proof: Adapt to new libraries/frameworks easily.
Test-friendly: Isolate layers for unit/integration tests.
Team-ready: Clear separation simplifies collaboration.
Quick Tips for Flutter
Use dependency injection (e.g., get_it, riverpod) to connect layers.
Keep the Domain layer pure (no BuildContext or widgets).
Start small! Even splitting UI and logic is a win.
Clean Architecture isn’t about perfection—it’s about intentional structure.
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