Why controllers handle incoming requests in NestJS - See It in Action

Why Controllers Handle Incoming Requests in NestJS

📖 Scenario: You are building a simple web server using NestJS. You want to organize your code so that it can respond to users' requests properly.

🎯 Goal: Learn how to create a controller in NestJS that handles incoming HTTP GET requests and sends back a response.

📋 What You'll Learn

Create a controller class named AppController

Add a method named getHello inside AppController

Use the @Controller() decorator on the class

Use the @Get() decorator on the getHello method

Return the string 'Hello World!' from getHello

💡 Why This Matters

🌍 Real World

Web servers use controllers to respond to user requests like loading pages or submitting forms.

💼 Career

Understanding controllers is essential for backend developers working with NestJS or similar frameworks to build APIs and web services.

1

Create the Controller Class

Create a class called AppController and decorate it with @Controller().

NestJS

@Controller()
// Your code here

Need a hint?

The @Controller() decorator marks the class as a controller that can handle requests.

2

Add a Method to Handle GET Requests

Inside AppController, add a method named getHello and decorate it with @Get().

NestJS

import { Controller, Get } from '@nestjs/common';

@Controller()
export class AppController {
  // Your code here
}

Need a hint?

The @Get() decorator tells NestJS this method handles GET requests.

3

Return a Response String

Make the getHello method return the string 'Hello World!'.

NestJS

import { Controller, Get } from '@nestjs/common';

@Controller()
export class AppController {
  @Get()
  getHello() {
    // Your code here
  }
}

Need a hint?

Returning a string sends it as the HTTP response body.

4

Complete the Controller Setup

Ensure the AppController class is exported and properly decorated with @Controller() and the getHello method is decorated with @Get() returning 'Hello World!'.

NestJS

import { Controller, Get } from '@nestjs/common';

// Your code here to complete the controller

Need a hint?

This is the complete controller that handles incoming GET requests and returns a response.