Layered architecture is a common software architecture pattern that organizes your web application into separate layers of responsibility and abstraction. It can help you achieve better modularity, testability, and maintainability of your code. In this article, you will learn how to implement layered architecture in web development using some basic principles and examples.
The typical layered architecture consists of four layers: presentation, business, data access, and data. Each layer has a distinct purpose and communicates with the adjacent layers through well-defined interfaces. The presentation layer handles the user interface and user interactions, which can be composed of HTML, CSS, JavaScript, or any other web framework or library that renders the web pages and captures the user input. The business layer contains the business logic and rules of your application, typically composed of classes, methods, functions, or any other programming constructs that implement the core functionality and validation of your application. The data access layer abstracts the access to the data sources of your application, such as repositories, queries, commands, or any other data access objects that interact with databases, APIs, or other external services. Finally, the data layer represents the data itself and can be composed of tables, records, documents, or any other data structures that store and retrieve the information of your application.
Layers are the group of similar logic, it can be any thing , as a human when need to architect a web app, it on you , design such that it will be easy to work with and maintain. So no such particular hard coded that there is presentation layer , data layer , but in most of the scenarios these are found helpfull hence these are considered as layers of abstract ideas like Layer 1 : Presentation Layer 2 : Business Logic Layer 3 : Data access Layer 4 : Core layer etc but as a architect its not restricted , its upon you , can decide based on the situation of your web app. If required please do if not please don't , or it may be two layers in one or may be not. or you can simply go with the crowd. Simple Layer is a group of similar logic.
Layered architecture has several benefits for web development. Separation of concerns can help you reduce complexity and increase cohesion, while reusability allows you to use the same components across different layers or applications. Additionally, testability and maintainability are improved since each layer can be tested independently and the code is more readable and understandable. For example, you can mock the data access layer to test the business layer or refactor one layer without breaking the functionality of the application.
Because of below benefits 1. Separation of Concerns 2. Loose Coupling 3. Layer-Specific Frameworks and Tools 4. Testing is easy 5. Security and Data Validation
To implement layered architecture in web development, it is essential to identify the layers, define the interfaces, implement the layers, and test the layers. When identifying the layers, you should analyze the requirements and features of your application and decide how many and which layers you need. You can also use the four-layer model as a reference or adapt it to your specific needs. To define the interfaces, you need to specify what data and operations each layer can expose and consume. For implementation, you can use various technologies and paradigms for different layers as long as they are compatible with the interfaces. Lastly, you need to test the layers individually and collectively using various testing methods, tools, and frameworks.
Layered architecture is not a silver bullet for web development and can present some challenges and drawbacks, such as performance issues due to overhead and latency in communication between layers. Complexity can also be an issue if there are too many or too fine-grained layers, making the codebase harder to understand. Additionally, it can be rigid, limiting design and development choices and making code less flexible. To address these issues, one should optimize interfaces, cache data, use asynchronous or parallel processing, keep layers simple and clear, and use a loose or flexible layered architecture that allows exceptions or variations.
Main challenge is to maintain the separation of concern. Suppose once the architect put all in place and create the different layer. In real time projects architect need to move to more important projects and team also changes with time, due to gap in knowledge and ability, its very hard to maintain the separation of concern. And once this separation of concern break, all the developers who follow the code break after them, because they have two choices 1. To maintain the consistency 2. To correct all the things , which is very time consuming. 90 percent of the time developer choose 1st option, and hence layered structure become messed up.
Layered architecture is a powerful and popular software architecture pattern that can help improve web development skills and results. To make the most of this pattern, you should use abstraction and encapsulation, practice dependency inversion, separate presentation and content, and employ domain-driven design. Hiding details and implementation between layers, making higher-level layers depend on abstractions, using a templating engine to bind presentation and content, and modeling the business layer according to the domain of the application can all help achieve low coupling, high cohesion, inversion of control, dependency injection, readability, usability, and accessibility. Following these principles can enable you to create more modular, testable, and maintainable web applications.