Layered architecture is a software design pattern commonly used in developing applications. This approach organizes the code into layers, each with a specific responsibility. By adhering to layered architecture principles, you can create a clean, maintainable, and scalable application.
To build a working application using a layered architecture, follow these key steps:
1. **Define the Layers**: Typically, layered architecture consists of at least three layers:
- Presentation Layer: This layer interacts with the user and displays information. It can be implemented using frameworks like React, Angular, or traditional web technologies.
- Business Logic Layer: This layer contains the application's core functionality. It processes requests from the presentation layer, applies business rules, and makes decisions.
- Data Access Layer: This layer manages data interactions, such as database access or API calls, and abstracts data storage details from the business logic.
2. **Set Up the Project Structure**: Create a directory structure that reflects the layers you've defined. For example:
- src/
- presentation/
- businessLogic/
- dataAccess/
3. **Implement the Presentation Layer**: Develop the user interface and handle user inputs. Connect this layer to the business logic layer by invoking methods or APIs.
4. **Implement the Business Logic Layer**: Write functional code that accomplishes specific tasks by processing inputs received from the presentation layer. This layer should not depend on the user interface.
5. **Implement the Data Access Layer**: Use database drivers or ORM (Object Relational Mapping) tools to interact with databases. This layer should provide methods to perform CRUD (Create, Read, Update, Delete) operations, ensuring that the business logic layer only interacts with this layer for data operations.
6. **Integrate the Layers**: Ensure that the presentation layer appropriately communicates with the business logic layer and that the business logic layer interacts with the data access layer. This typically involves defining service interfaces or APIs.
7. **Testing**: Unit test each layer independently, focusing on the functionality provided by the business and data access layers, while performing integration tests on the overall application.
8. **Deployment**: Choose a deployment strategy that suits your application, whether it's on-premises or cloud-based, and ensure the application is easily maintainable and scalable.
By following these steps, you will have a well-structured application that leverages the strengths of layered architecture, making it easier to manage and evolve over time.
