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name: Flutter Layer-based Clean Architecture + DDD description: Standards for separation of concerns, layer dependency rules, and DDD in Flutter. metadata: labels: [architecture, clean-architecture, layers, ddd] triggers: files: ['lib/domain/', 'lib/infrastructure/', 'lib/application/**'] keywords: [domain, infrastructure, application, presentation, layers, dto, mapper]

Layer-Based Clean Architecture

Priority: P0 (CRITICAL)

Standardized separation of concerns and dependency flow using DDD principles.

Structure

Copylib/
├── domain/ # Pure Dart: entities (@freezed), failures, repository interfaces
├── infrastructure/ # Implementation: DTOs, data sources, mappers, repo impls
├── application/ # Orchestration: BLoCs / Cubits
└── presentation/ # UI: Screens, reusable components

Implementation Guidelines

• Dependency Flow: Presentation -> Application -> Domain <- Infrastructure. Dependencies point inward.
• Pure Domain: No Flutter (Material/Store) or Infrastructure (Dio/Hive) dependencies in Domain.
• Functional Error Handling: Repositories must return Either<Failure, Success>.
• Always Map: Infrastructure must map DTOs to Domain Entities; do not leak DTOs to UI.
• Immutability: Use @freezed for all entities and failures.
• Logic Placement: No business logic in UI; widgets only display state and emit events.
• Inversion of Control: Use get_it to inject repository implementations into BLoCs.

Anti-Patterns

• No DTOs in UI: Never import a .g.dart or Data class directly in a Widget.
• No Material in Domain: Do not import package:flutter/material.dart in the domain layer.
• No Shared Prefs in Repo: Do not use shared_preferences directly in a Repository; use a Data Source.

Reference & Examples

For full implementation templates and DTO-to-Domain mapping examples: See references/REFERENCE.md.

Related Topics

feature-based-clean-architecture | bloc-state-management | dependency-injection | error-handling