di_generator_build library

A powerful build runner package for automatic dependency injection code generation using GetIt in Flutter applications.

This package provides a comprehensive solution for automatic dependency injection by analyzing your code and generating the necessary GetIt registration code. It supports various registration patterns including factories, singletons, and lazy singletons, with both synchronous and asynchronous initialization.

Quick Start

1. Add the package to your pubspec.yaml:

dev_dependencies:
  di_generator_build: ^1.2.0
  build_runner: ^2.5.4

2. Annotate your classes:

import 'package:di_generator_build/annotations.dart';

@RegisterSingleton()
class AppConfig {
  final String apiUrl;
  AppConfig({required this.apiUrl});
}

@RegisterLazySingleton()
class HttpClient {
  final AppConfig _config;
  HttpClient(this._config);
}

3. Run the code generator:

dart run build_runner build

4. Use the generated methods:

import 'your_file.g.dart';

void main() {
  final config = getAppConfig(apiUrl: 'https://api.example.com');
  final client = getHttpClient(); // Automatically gets AppConfig dependency
}

Available Annotations

• @RegisterFactory(): Creates new instance each time
• @RegisterSingleton(): Creates instance immediately and reuses it
• @RegisterLazySingleton(): Creates instance on first use, then reuses it
• @RegisterAsyncFactory(): Creates new async instance each time
• @RegisterAsyncSingleton(): Creates async instance immediately and reuses it
• @RegisterAsyncLazySingleton(): Creates async instance on first use, then reuses it

Features

• Automatic dependency resolution: Dependencies are automatically injected
• Lazy loading: Optimize performance by creating dependencies only when needed
• Async support: Handle asynchronous dependency creation and resolution
• Type safety: Full type safety with Dart's static analysis
• GetIt integration: Seamless integration with the GetIt service locator
• Build-time generation: No runtime overhead, all code generated at build time

Benefits

• Performance optimization: Lazy singletons create dependencies only when first requested
• Memory efficiency: Factories create new instances each time, singletons reuse instances
• Async initialization: Handle complex initialization scenarios with async support
• Clean architecture: Separate dependency creation from business logic
• Testability: Easy to mock and test with dependency injection

Configuration

Add to your build.yaml:

targets:
  $default:
    builders:
      di_generator_build|di_generator:
        enabled: true

Example

See the example/ directory for a complete working example.

Classes

DependencyInjectionGenerator

Generator that creates dependency injection methods for classes annotated with dependency injection annotations.

RegisterAsyncFactory

Annotation to mark a class for automatic async factory registration in GetIt.

RegisterAsyncLazySingleton

Annotation to mark a class for automatic async lazy singleton registration in GetIt.

RegisterAsyncSingleton

Annotation to mark a class for automatic async singleton registration in GetIt.

RegisterFactory

Annotation to mark a class for automatic factory registration in GetIt.

RegisterLazySingleton

Annotation to mark a class for automatic lazy singleton registration in GetIt.

RegisterSingleton

Annotation to mark a class for automatic singleton registration in GetIt.

SourceDirectoryBuilder

Custom builder that generates individual .g.dart files for each service.

Enums

RegisterAs

Enum to specify the type of dependency registration.

Extensions

GetItExtension on GetIt

Extension on GetIt to provide optimized lazy loading functionality.

Functions

buildDiGenerator(BuilderOptions options) → Builder

Builder for dependency injection code generation.