retail/docs/EXPORTS_DOCUMENTATION.md

Clean Architecture Export Files Documentation

This document describes all barrel export files created for the retail POS application, following clean architecture principles.

Overview

Barrel export files provide a clean, organized way to import code by:

• Simplifying imports across the codebase
• Enforcing layer separation and boundaries
• Making refactoring easier
• Improving IDE autocomplete
• Documenting module structure

File Structure

lib/
├── core/
│   ├── core.dart                      # Main core export
│   ├── config/
│   │   └── config.dart                # Configuration exports
│   ├── constants/
│   │   └── constants.dart             # All constants
│   ├── database/
│   │   └── database.dart              # Database utilities
│   ├── di/
│   │   └── di.dart                    # Dependency injection
│   ├── errors/
│   │   └── errors.dart                # Exceptions & failures
│   ├── network/
│   │   └── network.dart               # HTTP & network
│   ├── storage/
│   │   └── storage.dart               # Secure storage
│   ├── theme/
│   │   └── theme.dart                 # Material 3 theme
│   ├── utils/
│   │   └── utils.dart                 # Utilities & helpers
│   └── widgets/
│       └── widgets.dart               # Core widgets (already exists)
├── features/
│   ├── features.dart                  # Main features export
│   ├── auth/
│   │   ├── auth.dart                  # Main auth export
│   │   ├── data/
│   │   │   ├── data.dart              # Auth data layer
│   │   │   ├── datasources/
│   │   │   └── models/
│   │   │       └── models.dart        # Auth models
│   │   ├── domain/
│   │   │   ├── domain.dart            # Auth domain layer
│   │   │   └── entities/
│   │   │       └── entities.dart      # Auth entities
│   │   └── presentation/
│   │       ├── presentation.dart      # Auth presentation layer
│   │       ├── pages/
│   │       │   └── pages.dart         # Auth pages
│   │       └── widgets/
│   │           └── widgets.dart       # Auth widgets
│   ├── categories/
│   │   ├── categories.dart            # Main categories export
│   │   ├── data/
│   │   │   ├── data.dart              # Categories data layer
│   │   │   ├── datasources/
│   │   │   │   └── datasources.dart   # Category data sources
│   │   │   └── models/
│   │   │       └── models.dart        # Category models
│   │   ├── domain/
│   │   │   ├── domain.dart            # Categories domain layer
│   │   │   ├── entities/
│   │   │   │   └── entities.dart      # Category entities
│   │   │   └── usecases/
│   │   │       └── usecases.dart      # Category use cases
│   │   └── presentation/
│   │       ├── presentation.dart      # Categories presentation layer
│   │       ├── pages/
│   │       │   └── pages.dart         # Category pages
│   │       ├── providers/
│   │       │   └── providers.dart     # Category providers (already exists)
│   │       └── widgets/
│   │           └── widgets.dart       # Category widgets (already exists)
│   ├── home/
│   │   ├── home.dart                  # Main home/cart export
│   │   ├── data/
│   │   │   ├── data.dart              # Cart data layer
│   │   │   ├── datasources/
│   │   │   │   └── datasources.dart   # Cart data sources
│   │   │   └── models/
│   │   │       └── models.dart        # Cart models
│   │   ├── domain/
│   │   │   ├── domain.dart            # Cart domain layer
│   │   │   ├── entities/
│   │   │   │   └── entities.dart      # Cart entities
│   │   │   └── usecases/
│   │   │       └── usecases.dart      # Cart use cases
│   │   └── presentation/
│   │       ├── presentation.dart      # Cart presentation layer
│   │       ├── pages/
│   │       │   └── pages.dart         # Cart pages
│   │       ├── providers/
│   │       │   └── providers.dart     # Cart providers (already exists)
│   │       └── widgets/
│   │           └── widgets.dart       # Cart widgets (already exists)
│   ├── products/
│   │   ├── products.dart              # Main products export
│   │   ├── data/
│   │   │   ├── data.dart              # Products data layer
│   │   │   ├── datasources/
│   │   │   │   └── datasources.dart   # Product data sources
│   │   │   └── models/
│   │   │       └── models.dart        # Product models
│   │   ├── domain/
│   │   │   ├── domain.dart            # Products domain layer
│   │   │   ├── entities/
│   │   │   │   └── entities.dart      # Product entities
│   │   │   └── usecases/
│   │   │       └── usecases.dart      # Product use cases
│   │   └── presentation/
│   │       ├── presentation.dart      # Products presentation layer
│   │       ├── pages/
│   │       │   └── pages.dart         # Product pages
│   │       ├── providers/
│   │       │   └── providers.dart     # Product providers
│   │       └── widgets/
│   │           └── widgets.dart       # Product widgets (already exists)
│   └── settings/
│       ├── settings.dart              # Main settings export
│       ├── data/
│       │   ├── data.dart              # Settings data layer
│       │   ├── datasources/
│       │   │   └── datasources.dart   # Settings data sources
│       │   └── models/
│       │       └── models.dart        # Settings models
│       ├── domain/
│       │   ├── domain.dart            # Settings domain layer
│       │   ├── entities/
│       │   │   └── entities.dart      # Settings entities
│       │   └── usecases/
│       │       └── usecases.dart      # Settings use cases
│       └── presentation/
│           ├── presentation.dart      # Settings presentation layer
│           ├── pages/
│           │   └── pages.dart         # Settings pages
│           ├── providers/
│           │   └── providers.dart     # Settings providers (already exists)
│           └── widgets/
│               └── widgets.dart       # Settings widgets
└── shared/
    └── shared.dart                    # Shared components export

Usage Examples

1. Importing Entire Features

// Import complete auth feature (all layers)
import 'package:retail/features/auth/auth.dart';

// Import complete products feature
import 'package:retail/features/products/products.dart';

// Import all features at once
import 'package:retail/features/features.dart';

2. Importing Specific Layers

// Import only auth domain layer (entities + repositories)
import 'package:retail/features/auth/domain/domain.dart';

// Import only products presentation layer (pages + widgets + providers)
import 'package:retail/features/products/presentation/presentation.dart';

// Import only cart data layer
import 'package:retail/features/home/data/data.dart';

3. Importing Specific Components

// Import only auth entities
import 'package:retail/features/auth/domain/entities/entities.dart';

// Import only product models
import 'package:retail/features/products/data/models/models.dart';

// Import only category use cases
import 'package:retail/features/categories/domain/usecases/usecases.dart';

// Import only product providers
import 'package:retail/features/products/presentation/providers/providers.dart';

4. Importing Core Utilities

// Import all core utilities
import 'package:retail/core/core.dart';

// Import only constants
import 'package:retail/core/constants/constants.dart';

// Import only theme
import 'package:retail/core/theme/theme.dart';

// Import only network utilities
import 'package:retail/core/network/network.dart';

// Import only error handling
import 'package:retail/core/errors/errors.dart';

5. Importing Shared Components

// Import shared widgets
import 'package:retail/shared/shared.dart';

Clean Architecture Benefits

Layer Isolation

The export structure enforces clean architecture principles:

// ✅ GOOD: Domain layer importing from domain
import 'package:retail/features/products/domain/domain.dart';

// ❌ BAD: Domain layer importing from data/presentation
// Domain should never depend on outer layers
import 'package:retail/features/products/data/data.dart';

Dependency Flow

Dependencies flow inward:

• Presentation → Domain ← Data
• Data → Domain (implements interfaces)
• Domain → Independent (pure business logic)

// In presentation layer - ✅ GOOD
import 'package:retail/features/products/domain/domain.dart';

// In data layer - ✅ GOOD
import 'package:retail/features/products/domain/domain.dart';

// In domain layer - ❌ NEVER
// import 'package:retail/features/products/data/data.dart';
// import 'package:retail/features/products/presentation/presentation.dart';

Feature Export Hierarchy

Each feature follows this export hierarchy:

feature.dart                    # Top-level feature export
├── data/data.dart              # Data layer export
│   ├── datasources/datasources.dart
│   ├── models/models.dart
│   └── repositories/           # Implementations (exported directly)
├── domain/domain.dart          # Domain layer export
│   ├── entities/entities.dart
│   ├── repositories/           # Interfaces (exported directly)
│   └── usecases/usecases.dart
└── presentation/presentation.dart  # Presentation layer export
    ├── pages/pages.dart
    ├── providers/providers.dart
    └── widgets/widgets.dart

Import Guidelines

DO's

1. Import at the appropriate level

   // If you need the entire feature
   import 'package:retail/features/auth/auth.dart';
   
   // If you only need domain entities
   import 'package:retail/features/auth/domain/entities/entities.dart';
   

2. Use barrel exports for cleaner code

   // ✅ Clean and maintainable
   import 'package:retail/features/products/presentation/presentation.dart';
   
   // ❌ Messy and fragile
   import 'package:retail/features/products/presentation/pages/products_page.dart';
   import 'package:retail/features/products/presentation/widgets/product_card.dart';
   import 'package:retail/features/products/presentation/widgets/product_grid.dart';
   import 'package:retail/features/products/presentation/providers/products_provider.dart';
   

3. Respect layer boundaries

   // In a use case (domain layer)
   import 'package:retail/features/products/domain/domain.dart'; // ✅
   import 'package:retail/core/core.dart'; // ✅ (core is shared)
   

DON'Ts

1. Don't bypass barrel exports

   // ❌ Bypasses barrel export
   import 'package:retail/features/products/data/models/product_model.dart';
   
   // ✅ Use barrel export
   import 'package:retail/features/products/data/models/models.dart';
   

2. Don't violate layer dependencies

   // In domain layer
   // ❌ Domain depends on outer layers
   import 'package:retail/features/products/data/data.dart';
   import 'package:retail/features/products/presentation/presentation.dart';
   

3. Don't import entire feature when you need one layer

   // ❌ Over-importing
   import 'package:retail/features/products/products.dart'; // Imports all layers
   // When you only need:
   import 'package:retail/features/products/domain/entities/entities.dart';
   

Benefits Summary

1. Clean Imports

Before:

import 'package:retail/features/products/data/models/product_model.dart';
import 'package:retail/features/products/domain/entities/product.dart';
import 'package:retail/features/products/domain/repositories/product_repository.dart';
import 'package:retail/features/products/presentation/pages/products_page.dart';
import 'package:retail/features/products/presentation/widgets/product_card.dart';
import 'package:retail/features/products/presentation/widgets/product_grid.dart';

After:

import 'package:retail/features/products/products.dart';

2. Layer Isolation

• Domain layer never imports from data/presentation
• Each layer has clear boundaries
• Enforces dependency inversion

3. Easy Refactoring

• Change internal structure without breaking imports
• Move files within a layer without updating imports
• Rename files without affecting external code

4. Better IDE Support

• Autocomplete shows only exported items
• Easier to navigate code structure
• Clear module boundaries

5. Documentation

• Export files serve as documentation
• Shows what's public vs private
• Makes architecture explicit

Migration Guide

If you have existing imports, migrate them gradually:

Step 1: Update feature-level imports

// Old
import 'package:retail/features/products/presentation/pages/products_page.dart';

// New
import 'package:retail/features/products/presentation/pages/pages.dart';

Step 2: Consolidate layer imports

// Old
import 'package:retail/features/products/presentation/pages/pages.dart';
import 'package:retail/features/products/presentation/widgets/widgets.dart';
import 'package:retail/features/products/presentation/providers/providers.dart';

// New
import 'package:retail/features/products/presentation/presentation.dart';

Step 3: Use top-level feature import when appropriate

// If you need multiple layers
import 'package:retail/features/products/products.dart';

Complete File List

Total export files created: 54 files

Core Module (10 files)

1. /Users/ssg/project/retail/lib/core/core.dart
2. /Users/ssg/project/retail/lib/core/config/config.dart
3. /Users/ssg/project/retail/lib/core/constants/constants.dart
4. /Users/ssg/project/retail/lib/core/database/database.dart
5. /Users/ssg/project/retail/lib/core/di/di.dart
6. /Users/ssg/project/retail/lib/core/errors/errors.dart
7. /Users/ssg/project/retail/lib/core/network/network.dart
8. /Users/ssg/project/retail/lib/core/storage/storage.dart
9. /Users/ssg/project/retail/lib/core/theme/theme.dart
10. /Users/ssg/project/retail/lib/core/utils/utils.dart

Auth Feature (8 files)

11. /Users/ssg/project/retail/lib/features/auth/auth.dart
12. /Users/ssg/project/retail/lib/features/auth/data/data.dart
13. /Users/ssg/project/retail/lib/features/auth/data/models/models.dart
14. /Users/ssg/project/retail/lib/features/auth/domain/domain.dart
15. /Users/ssg/project/retail/lib/features/auth/domain/entities/entities.dart
16. /Users/ssg/project/retail/lib/features/auth/presentation/presentation.dart
17. /Users/ssg/project/retail/lib/features/auth/presentation/pages/pages.dart
18. /Users/ssg/project/retail/lib/features/auth/presentation/widgets/widgets.dart (updated by flutter expert)

Products Feature (10 files)

19. /Users/ssg/project/retail/lib/features/products/products.dart
20. /Users/ssg/project/retail/lib/features/products/data/data.dart
21. /Users/ssg/project/retail/lib/features/products/data/datasources/datasources.dart
22. /Users/ssg/project/retail/lib/features/products/data/models/models.dart
23. /Users/ssg/project/retail/lib/features/products/domain/domain.dart
24. /Users/ssg/project/retail/lib/features/products/domain/entities/entities.dart
25. /Users/ssg/project/retail/lib/features/products/domain/usecases/usecases.dart
26. /Users/ssg/project/retail/lib/features/products/presentation/presentation.dart
27. /Users/ssg/project/retail/lib/features/products/presentation/pages/pages.dart
28. /Users/ssg/project/retail/lib/features/products/presentation/providers/providers.dart

Categories Feature (10 files)

29. /Users/ssg/project/retail/lib/features/categories/categories.dart
30. /Users/ssg/project/retail/lib/features/categories/data/data.dart
31. /Users/ssg/project/retail/lib/features/categories/data/datasources/datasources.dart
32. /Users/ssg/project/retail/lib/features/categories/data/models/models.dart
33. /Users/ssg/project/retail/lib/features/categories/domain/domain.dart
34. /Users/ssg/project/retail/lib/features/categories/domain/entities/entities.dart
35. /Users/ssg/project/retail/lib/features/categories/domain/usecases/usecases.dart
36. /Users/ssg/project/retail/lib/features/categories/presentation/presentation.dart
37. /Users/ssg/project/retail/lib/features/categories/presentation/pages/pages.dart
38. /Users/ssg/project/retail/lib/features/categories/presentation/providers/providers.dart (already exists)

Home/Cart Feature (10 files)

39. /Users/ssg/project/retail/lib/features/home/home.dart
40. /Users/ssg/project/retail/lib/features/home/data/data.dart
41. /Users/ssg/project/retail/lib/features/home/data/datasources/datasources.dart
42. /Users/ssg/project/retail/lib/features/home/data/models/models.dart
43. /Users/ssg/project/retail/lib/features/home/domain/domain.dart
44. /Users/ssg/project/retail/lib/features/home/domain/entities/entities.dart
45. /Users/ssg/project/retail/lib/features/home/domain/usecases/usecases.dart
46. /Users/ssg/project/retail/lib/features/home/presentation/presentation.dart
47. /Users/ssg/project/retail/lib/features/home/presentation/pages/pages.dart
48. /Users/ssg/project/retail/lib/features/home/presentation/providers/providers.dart (already exists)

Settings Feature (10 files)

49. /Users/ssg/project/retail/lib/features/settings/settings.dart
50. /Users/ssg/project/retail/lib/features/settings/data/data.dart
51. /Users/ssg/project/retail/lib/features/settings/data/datasources/datasources.dart
52. /Users/ssg/project/retail/lib/features/settings/data/models/models.dart
53. /Users/ssg/project/retail/lib/features/settings/domain/domain.dart
54. /Users/ssg/project/retail/lib/features/settings/domain/entities/entities.dart
55. /Users/ssg/project/retail/lib/features/settings/domain/usecases/usecases.dart
56. /Users/ssg/project/retail/lib/features/settings/presentation/presentation.dart
57. /Users/ssg/project/retail/lib/features/settings/presentation/pages/pages.dart
58. /Users/ssg/project/retail/lib/features/settings/presentation/providers/providers.dart (already exists)
59. /Users/ssg/project/retail/lib/features/settings/presentation/widgets/widgets.dart

Top-Level Exports (2 files)

60. /Users/ssg/project/retail/lib/features/features.dart
61. /Users/ssg/project/retail/lib/shared/shared.dart

Documentation (1 file)

62. /Users/ssg/project/retail/lib/EXPORTS_DOCUMENTATION.md

---

Maintenance

When adding new files to the project:

1. New file in existing module: Update the appropriate barrel export
2. New module: Create new barrel exports following the pattern
3. Removing files: Update barrel exports to remove deleted exports
4. Renaming files: Update barrel exports to reflect new names

Support

For questions or issues with the export structure, refer to:

• This documentation
• Clean Architecture principles
• Feature-first organization patterns