NestJS is a powerful framework for building efficient, reliable, and scalable server-side applications with Node.js. It’s built with TypeScript and heavily inspired by Angular, which makes it familiar for developers who have experience with Angular or any similar frontend frameworks. Here’s a basic guide to get you started with NestJS:
Installation: You can install NestJS CLI globally using npm or yarn. This CLI helps you to bootstrap new projects, generate modules, controllers, services, etc. Run the following command to install NestJS CLI:
npm install -g @nestjs/cli
Create a New Project: After installing the CLI, you can create a new NestJS project using the nest new command followed by your project name. For example:
nest new my-nest-project
Project Structure: NestJS follows a modular structure. When you create a new project, it will generate a basic structure for you. The main files and directories you’ll work with are:
– `src/main.ts`: The entry point of your application.
– `src/app.module.ts`: The root module of your application.
Modules: Modules are a way to organize your application into logical blocks. Each application has at least one module, the root module (app.module.ts). You can create additional modules to organize your code better. To generate a new module, you can use the CLI:
nest generate module <module-name>
Controllers: Controllers are responsible for handling incoming requests and returning responses to the client. They are bound to specific routes. You can generate a new controller using the CLI:
nest generate controller <controller-name>
Services: Services are used to encapsulate reusable logic. They are typically injected into controllers and other services. You can generate a new service using the CLI:
nest generate service <service-name>
Dependency Injection: NestJS leverages the concept of dependency injection to manage the dependencies between different components of your application. You can inject services into controllers, other services, and modules.
Middleware: Middleware functions are functions that have access to the request and response objects. They can execute any code, make changes to the request and response objects, end the request-response cycle, and call the next middleware function in the stack. You can create custom middleware to handle cross-cutting concerns like logging, authentication, etc.
Interceptors: Interceptors are used to intercept and modify the behavior of NestJS components. They can be attached to controllers or individual methods within a controller.
Exception Filters: Exception filters are used to catch exceptions thrown by your application. You can create custom exception filters to handle errors gracefully and return appropriate responses to the client.
This is just a basic overview of NestJS. As you start building applications with NestJS, you’ll dive deeper into more advanced concepts and features. The official NestJS documentation is an excellent resource for learning more about the framework and its capabilities.
Disclaimer: This content in generated by AI.
