Curious about how modern web applications work behind the scenes? In this article, we’ll simplify the MVC model, showing how it neatly organizes code into models, routes, controllers, and more. Discover how this structure helps build efficient, scalable applications and makes your backend code easy to manage. Let’s break it down and make backend development a breeze!
The MVC (Model-View-Controller) model is a common way to organize code in backend applications, and it helps to separate concerns so the system is easier to manage and understand. Here’s a simple explanation of how a basic backend application works and how the different parts fit into the MVC model:
Basic Flow of a Backend Application:
Client: This is the user or application that wants to access some data or perform an action. For example, a user filling out a form on a website. It may also be understood as the browser (eg. chrome) in simple terms.
API: The client sends a request to the backend through an API (Application Programming Interface). The API defines how different parts of the application interact and communicate with each other. It acts as a bridge between frontend(on browser) and backend(server) requesting from server through get, post, put and delete methods.
Backend: This is where the application logic lives. It processes the request from the client, interacts with the database if needed, and sends back a response.
Database (DB): This is where data is stored. The backend retrieves or updates data in the database based on the client’s request.
MVC Model Explained with Components:
Model:
Function: Represents the data and business logic. It’s where the application's core data structures and rules are defined.
Example: If you have a user model, it might define what data a user has (like name, email) and how to interact with that data.
Database:
Function: Stores all the application data. This is where the actual data is saved and retrieved from.
Example: A database might have tables for users, orders, products, etc.
Routes:
Function: Define how URLs (web addresses) map to specific actions in the application. Routes determine which part of the backend should handle a given request.
Example: A route like /users might map to a function that shows all users. It means when we hit this path, what functionality should be triggered at backend, which middleware should be passed before it etc.
Controllers:
Function: Handle the incoming requests, use the models to get or update data, and then send a response back to the client. Controllers act as the middlemen between the routes and the models.
Example: A userController might have actions to create a new user, delete a user, or fetch user details.
Middlewares:
Function: Perform tasks before or after the main request handling. They can be used for things like authentication (checking if the user is logged in), logging, or modifying the request/response.
Example: An authentication middleware might check if a user is logged in before allowing access to certain routes. This is necessary when we want to make sure the user is logged in before serving him userProfile page, else he should be directed to login form first.
Utils:
Function: Contain helper functions or utilities that can be used throughout the application. They don’t fit neatly into models, controllers, or other parts but are useful for various tasks.
Example: A utility function might format dates or handle common tasks like sending emails.
Flow of Control in MVC Model:
Client Request: The client makes a request to a specific URL.
Routes: The request is matched to a route, which then directs it to the appropriate controller.
Controllers: The controller processes the request, interacting with the model to retrieve or update data as needed.
Model: The controller uses the model to get or save data from/to the database.
Database: If needed, the model retrieves or updates data in the database.
Middlewares: Any middleware defined for the route or controller runs before or after the main request handling.
Response: The controller prepares the response and sends it back to the client.
Client Receives Response: The client gets the response and displays or processes the data as needed.
This structure helps keep the code organized and makes it easier to manage and scale as the application grows.