Scalable API Template for Node.js Applications

How to RUN

• There are NPM scripts to help your development enviroment easy

NPM Scripts

• Use npm run dev to start the app in development mode
• Go to http://localhost:PORT_NUMBER to see the app running

Code Structure

This codebase follows MVC pattern with few additional layers.

List of layers

The codebase has following flow of different layers:

• Routes
  • Controllers
    • Request Validators
    • Service Layer
    • Dispatch Response

Routes

• Routes are the top level and are created using Express.js routes
• They internally calls the controllers
• Every route has it's own controller

Controllers

• Controller is invoked by it's route
• Controllers at it's core has following responsiblities:
  • Validation of the client request
  • Extract the request entities (body, params or query)
  • Invokes different services
  • Returns the final response back to the client

Request Validators

• This layer is a set of custom functions in a separate file
• They are used to validate the client request be it the body, params or query of the request
• If the client request is not desireable, it returns the errors back to the client

Service Layers

• This layer primarily interacts with the Database
• It is reponsible only for getting the required data from the Database and return it to the controller
• Note: All the business logic and query filteration should take place inside the controller

Libraries Used

• Express.js
• Express Validator
• Mongoose

HTTP Verbs Used

• GET : Use this to fetch data from the DB to client
• POST: Use this when creating new record in DB
• PATCH: Use this when you partially update any entity
• DELETE: Use this when you are performing delete operation

HTTP Status Code Used

• 200 - Used when you get data successfully

• 201 - Used when your data created successfully

• 400 - Used when there is bad request from the client

• 401 - Used when user is not authenticated

• 403 - Used when user is authenticated but do not have permissions to access resource

• 404 - Used when data not found

• 422 - Used when payload key(s) is valid but the data in the key(s) are unprocessable

• 500 - Used when server encounter unexpected condition