A use case of Clean Architecture in Node.js comprising of Express.js, MongoDB and Redis as the main (but replaceable) infrastructure.
This example is a simple RESTful API application in which a user can create / update / delete / find a post, by using the Clean Architecture.
The objective of Clean Architecture by Robert C. Martin is the separation of concerns in software. This separation is achieved by dividing the software into layers. Each layer is encapsulated by a higher level layer and the way to communicate between the layers is with the Dependency Rule.
This rule says that nothing in an inner circle can know anything at all about something in an outer circle. The dependency direction is from the outside in. Meaning that the Entities layer is independent and the Frameworks & Drivers layer (Web, UI, DB etc.) depends on all the other layers.
Contains all the business entities an application consists of. In our example the User and the Post.
Contains application specific business rules. These use cases orchestrate the flow of data to and from the entities. In our example some of the use cases are: AddPost, AddUser, DeleteById etc.
This layer is a set of adapters (controllers, presenters, and gateways) that convert data from the format most convenient for the use cases and entities, to the format most convenient for some external agency such as the DB or the Web. In other words, is an entry and exit points to the Use Cases layer. In our example we implemented controllers and presenters together and these are the PostController and the UserController.
The outermost layer is generally composed of frameworks and tools such as the Database, the Web Framework, etc.
- Make sure you have mongoDB installed. At the terminal run the following command:
mongod --dbpath <path_to_data/db_folder>- Make sure Redis is also installed and running.
- Run the server in development mode by typing the following command:
npm run dev- Run the server in production mode by typing the following command:
npm run start- Make sure you have docker installed. At the root folder run the following command:
docker-compose up -d