Controller decorator in NestJS - Mini Project: Build & Apply

Building a Simple NestJS Controller with @Controller Decorator

📖 Scenario: You are creating a simple web server using NestJS. You want to organize your routes by creating a controller that handles HTTP requests for a specific path.

🎯 Goal: Build a NestJS controller class using the @Controller decorator to define a route prefix.

📋 What You'll Learn

Create a controller class named AppController

Use the @Controller decorator with the path 'app'

Add a method named getHello inside the controller

Use the @Get decorator on the getHello method with no path argument

Return the string 'Hello World!' from the getHello method

💡 Why This Matters

🌍 Real World

Controllers in NestJS organize routes and handle HTTP requests in web applications and APIs.

💼 Career

Understanding controllers and decorators is essential for backend development with NestJS, a popular Node.js framework.

1

Create the controller class

Create a class named AppController in your file.

NestJS

# Create a class named AppController
# Your code here

Need a hint?

Use the class keyword followed by AppController and curly braces.

2

Add the @Controller decorator with path 'app'

Add the @Controller('app') decorator above the AppController class definition. Also import Controller from @nestjs/common.

NestJS

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

// Add @Controller('app') decorator below
export class AppController {
}
# Your code here

Need a hint?

Remember to import Controller and place @Controller('app') right before the class.

3

Add a getHello method with @Get decorator

Import Get from @nestjs/common. Inside AppController, add a method named getHello decorated with @Get() that returns the string 'Hello World!'.

NestJS

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

@Controller('app')
export class AppController {
  // Add getHello method with @Get decorator
  // Your code here
}

Need a hint?

Use @Get() above the method and return the exact string 'Hello World!'.

4

Complete the controller export

Ensure the AppController class is exported as default export by adding export default AppController; at the end of the file.

NestJS

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

@Controller('app')
export class AppController {
  @Get()
  getHello(): string {
    return 'Hello World!';
  }
}

// Export AppController as default
# Your code here

Need a hint?

Use export default AppController; at the end of the file to complete the export.