Nest JS Overview: Understanding the Project, Modules, and a Comprehensive Course

Nest JS is a powerful and versatile Node.js framework that is used to build efficient, scalable, and maintainable web applications. It is built on top of Express.js and provides an abstracted layer on top of it to facilitate the development of server-side applications. Nest JS follows the modular architecture concept, which makes it easy to organize code and maintain a structured project. In this tutorial, we will cover the basics of Nest JS, how to create a Nest JS project, and how to create and work with modules.

What is Nest JS:
Nest JS is a server-side web application framework that is built with Typescript and is based on modular architecture. It provides developers with a set of tools and modules to easily create high-quality and scalable web applications. Nest JS is inspired by Angular and adopts many of its features and principles, such as dependency injection, decorators, and modules.

Creating a Nest JS Project:
To create a new Nest JS project, you first need to have Node.js and npm (Node Package Manager) installed on your system. You can check if you have Node.js installed by running the following command in your terminal:

node -v

If you don’t have Node.js installed, you can download and install it from the official website (https://nodejs.org/).

Once you have Node.js installed, you can create a new Nest JS project using the Nest CLI (Command Line Interface). To install the Nest CLI globally, run the following command in your terminal:

npm install -g @nestjs/cli

After installing the Nest CLI, you can create a new Nest JS project by running the following command:

nest new project-name

Replace "project-name" with the name of your project. This command will create a new Nest JS project with the specified name in the current directory.

Working with Modules:
In Nest JS, modules are a way to organize the codebase of your application into smaller, cohesive units. Each module encapsulates a set of related components, controllers, services, and providers. Modules help to keep your codebase clean, maintainable, and easier to manage.

To create a new module in your Nest JS project, you can use the Nest CLI to generate a module template. Run the following command in your terminal to generate a new module:

nest generate module module-name

Replace "module-name" with the name of your module. This command will create a new module with the specified name in the "modules" directory of your project.

Each module in Nest JS consists of a module file (module.ts), a controller file (controller.ts), and a service file (service.ts). The module file defines the module’s dependencies, the controller file contains the request handling logic, and the service file contains the business logic.

To use a module in your application, you need to import it into the main application module (app.module.ts) using the ‘@Module’ decorator. Here’s an example of how to import a module into the main application module:

@Module({
  imports: [ModuleName],
  controllers: [ControllerName],
  providers: [ServiceName],
})
export class AppModule {}

Replace "ModuleName", "ControllerName", and "ServiceName" with the names of the module, controller, and service that you want to import.

In conclusion, Nest JS is a powerful and flexible framework that allows you to easily create scalable and maintainable web applications. By following the modular architecture concept and organizing your code into modules, you can build high-quality applications with Nest JS. I hope this tutorial has helped you understand the basics of Nest JS and how to create and work with modules.