Flutter Feature Based Clean Architecture

Feature-Based Clean Architecture

Priority: P0 (CRITICAL)

Standard for modular Clean Architecture organized by business features in lib/features/.

Structure

Every feature lives in lib/features/ with 3-layer separation (domain/data/presentation):

• domain/ — Entities, failures, and Repository interfaces.
• data/ — DTOs, DataSource, and Repository implementations.
• presentation/ — BLoC/Cubit, pages, and widgets.

See references/folder-structure.md for the complete directory blueprint.

Implementation Guidelines

• Feature Encapsulation: Keep all logic, models, and UI internal to the feature directory (e.g., lib/features/promotions/).
• Strict Layering: Maintain domain/data/presentation separation within each feature.
• Dependency Rule: Presentation -> Domain <- Data. Domain must have zero external dependencies.
• Cross-Feature Communication: Features only depend on the Domain layer of other features. Ensure there are no cross-feature presentation or data imports.
• Flat features: Keep lib/features/ flat; avoid nested features.
• No DTO Leakage: Never expose DTOs or Data Sources to UI or other features; return Domain Entities.
• Shared logic: Move cross-cutting concerns to lib/shared/ or lib/core/.

Reference & Examples

For feature folder blueprints and cross-layer dependency templates: See references/REFERENCE.md.

Anti-Patterns

• ❌ import '…/features/orders/data/models/order_dto.dart' from another feature — only import Domain types across features
• ❌ lib/features/orders/domain/widgets/ — never put UI or Data classes inside Domain
• ❌ lib/features/orders/sub_orders/ — keep lib/features/ flat; no nested feature directories
• ❌ Calling another feature's repository directly from Presentation — route through that feature's BLoC or use-case

Related Topics

layer-based-clean-architecture | retrofit-networking | go-router-navigation | bloc-state-management | dependency-injection