dart_mediatr 1.0.1 dart_mediatr: ^1.0.1 copied to clipboard
Simple, unambitious dart_mediatr implementation in Flutter
Dart Mediator Package #
The Dart Mediator package provides an implementation of the Mediator pattern for Dart, including dynamic handler registration via code generation. This pattern is useful for organizing your application's commands and queries by centralizing their processing through a mediator.
The Mediator pattern is a behavioral design pattern that centralizes request handling and execution. It promotes loose coupling between components by removing direct dependencies between them. Instead of components communicating directly with each other, they communicate through a mediator object. This allows for more flexible and maintainable code, as components can be easily added, removed, or modified without affecting other components.
Features #
- Mediator Pattern: Centralizes request handling and execution.
- Dynamic Handler Registration: Automatically registers handlers using code generation.
- CQRS Support: Facilitates separation of commands (state changes) and queries (data retrieval).
- Command and Query Handlers: Supports both command and query handlers.
- Handler Annotations: Use annotations to auto-register handlers using code generation.
- Handler Registration: Manually register handlers using the
registerCommandHandler
andregisterQueryHandler
methods. - Handler Interface: Implement the
CommandHandler
andQueryHandler
interfaces to create custom handlers.
Getting Started #
Installation #
To use the Dart Mediator package, add it to your pubspec.yaml
:
dependencies:
dart_mediatr: ^1.0.0
Then, run dart pub get to install the package.
Usage #
To use the Mediator package, you need to create a Mediator
instance and register your handlers. The Mediator
class
is the central component that processes requests and routes them to the appropriate handler.
you can register handlers using the registerCommandHandler
and registerQueryHandler
methods.
or using the Handler
annotation to auto register handlers using code generation.
To automatically register handlers, use the build_runner
package. Add the package to your dev_dependencies
in
pubspec.yaml
:
dev_dependencies:
build_runner: ^2.0.0
then add the Handler
annotation to your handler classes:
import 'package:dart_mediatr/dart_mediatr.dart';
import 'create_user_command.dart';
import 'create_user_command_response.dart';
@Handler()
class CreateUserCommandHandler
implements CommandHandler<CreateUserCommand, CreateUserCommandResponse> {
@override
CreateUserCommandResponse handle(CreateUserCommand command) {
print('User ${command.name} created.');
return CreateUserCommandResponse();
}
}
then add the @MediatorInit()
annotation to your main function:
import 'package:dart_mediatr/dart_mediatr.dart';
@MediatorInit()
void main() async {
registerAllHandlers();
runApp(const MyApp());
}
Then, run the build_runner to generate the registration code:
dart run build_runner build
then import the generated file in your main file and invoke the registerAllHandlers
function:
import 'main.mediator.dart';
@MediatorInit()
Future<void> main() async {
registerAllHandlers();
runApp(const MyApp());
}
if you hate generated code and you want to manually register handlers, use the registerCommandHandler
and
registerQueryHandler
methods:
import 'package:dart_mediatr/dart_mediatr.dart';
void main() async {
Mediator mediator = Mediator();
mediator.registerCommandHandler(CreateUserCommandHandler());
runApp(const MyApp());
}
Contributing #
Contributions are welcome! Please follow these steps to contribute:
- Fork the repository.
- Create a new branch (
git checkout -b feature-branch
). - Make your changes.
- Run the tests (
dart test
). - Commit your changes (
git commit -am 'Add new feature'
). - Push to the branch (
git push origin feature-branch
). - Create a new Pull Request.
- Get your changes reviewed.
License #
This package is licensed under the MIT License. See the LICENSE file for details.