Clean Architecture is an approach to software development that emphasizes the separation of concerns and independence from external frameworks, libraries, and technologies. It consists of several layers, each with its responsibilities and dependencies.
Key Principles of Clean Architecture
UI-independent: The UI is separated from the business logic and can be easily changed without affecting the rest of the system.
Independent of external technologies: The system is not dependent on specific frameworks, libraries, or databases.
Separation of concerns: The system is divided into several layers, each with its responsibilities and dependencies.
Dependency rule: The inner layers do not depend on the outer layers. This makes the system more modular and easier to maintain.
Layers in Clean Architecture
Clean Architecture typically consists of the following layers, arranged hierarchically:
Entities: The core of the business logic, containing enterprise-wide business rules and data transfer objects.
Use cases: Defines the application-specific business rules and interacts with the Entities layer.
Interface adapters: Converts data between the Use Cases and external technologies, such as the UI, databases, and web services.
Frameworks and drivers: Implements external technologies and provides concrete implementations for the Interface Adapters layer.
Implementing Clean Architecture in Android
To implement Clean Architecture in Android, you can follow these steps:
Create three modules: Presentation, Data, and Domain. The Presentation module contains the UI, the Data module contains the data sources (such as databases and web services), and the Domain module contains the business logic.
Use MVVM (Model-View-ViewModel) pattern in the Presentation layer, because it's supported by Android Jetpack. However, you can use any other pattern that suits your needs.
Use Dagger Hilt (or Koin) for dependency injection and Kotlin Coroutines and Flows for performing Network and Database Operations in the background thread.
Use Room for database access, ViewModel for managing UI-related data, LiveData for observing data changes, and Paging Library for loading data gradually in RecyclerView.
Implement each layer independently, following the dependency rule.
Benefits of Clean Architecture
By following Clean Architecture in Android, you can achieve several benefits, such as:
Separation of concerns and modularity: The system is divided into several layers, each with its responsibilities and dependencies. This makes the system more modular and easier to maintain.
Testability: Each layer can be tested independently, making it easier to write automated tests.
Flexibility: The system is not dependent on specific frameworks, libraries, or technologies, making it easier to adapt to changing requirements.
Readability and maintainability: The system is organized clearly and understandably, making it easier to read and maintain the code.
When to use Clean Architecture
Clean Architecture is suitable for medium to high-complexity Android projects with a lot of business logic. For smaller and simpler projects, the benefits of Clean Architecture might not be worth the additional complexity. It's important to decide based on the project requirements and constraints.
Overall, Clean Architecture is a powerful approach to software development that can help you build robust, flexible, and maintainable Android applications.