Custom Libraries

About

Code Organization: Logical grouping
Privacy Control: Hide implementation
Reusability: Share across projects
Structure: Multiple files

Main Topics

Library Declaration
- Definition: library keyword
- Example:
```
library my_awesome_library;
```

Part Files

Definition: Split implementation

Example:

part 'src/implementation.dart';
part 'src/helpers.dart';

Export Directives

Definition: Public API

Example:

export 'src/public.dart';
export 'src/types.dart';

Private Implementation
- Definition: src/ directory
- Example:
```
lib/
  my_library.dart
  src/
    implementation.dart
```

Documentation

Definition: API docs

Example:

/// A utility library for string operations
library string_utils;

How to Use

Structure: Logical modules
Privacy: Hide implementation
Documentation: Explain purpose
Testing: Test public API

How It Works

Scope: Library boundary
Privacy: _ prefix
Composition: Parts form one library
Distribution: Via packages

Example:

// lib/weather.dart
library weather;

export 'src/models.dart';
export 'src/api.dart';
export 'src/exceptions.dart';

// Implementation files in src/

Conclusion

Custom libraries in Dart enable clean code organization through logical grouping and controlled visibility. By using library declarations, part files, and export directives, developers can create well-structured, maintainable codebases with clear public APIs.