Sessions
In NestJS, session management is implemented by integrating third-party libraries such as express-session. Session management is a critical component of web development, used to track user activity and maintain user state across multiple requests.
Installing Dependencies
First, install express-session and its related dependencies.
npm install express-sessionConfiguring Sessions
Next, configure the session middleware in your NestJS application.
import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import * as session from 'express-session';
async function bootstrap() {
const app = await NestFactory.create(AppModule);
// Configure session middleware
app.use(session({
secret: 'your-secret-key',
resave: false,
saveUninitialized: false,
cookie: {
maxAge: 1000 * 60 * 60 * 24 * 7, // One week
httpOnly: true,
secure: false, // Set to true for HTTPS only
sameSite: 'strict', // Or 'lax' or 'none'
},
}));
await app.listen(3000);
}
bootstrap();Using Sessions
Once the session middleware is configured, you can use req.session in controllers to read and set session data.
import { Controller, Get, Req } from '@nestjs/common';
@Controller()
export class AppController {
@Get('/set-session')
setSession(@Req() req) {
req.session.views = (req.session.views || 0) + 1;
return { views: req.session.views };
}
@Get('/get-session')
getSession(@Req() req) {
return { views: req.session.views };
}
}Session Storage
By default, express-session stores session data in the client’s cookie. For persistent session storage, you can use external storage services like Redis or MongoDB.
import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import * as session from 'express-session';
import RedisStore from 'connect-redis';
import redis from 'redis';
const client = redis.createClient();
async function bootstrap() {
const app = await NestFactory.create(AppModule);
// Use Redis to store session data
app.use(session({
store: new RedisStore({ client }),
secret: 'your-secret-key',
resave: false,
saveUninitialized: false,
cookie: {
maxAge: 1000 * 60 * 60 * 24 * 7, // One week
httpOnly: true,
secure: false, // Set to true for HTTPS only
sameSite: 'strict', // Or 'lax' or 'none'
},
}));
await app.listen(3000);
}
bootstrap();Cookies
In NestJS, handling cookies is typically achieved by integrating third-party libraries such as express and cookie-parser. Cookies are a common technique for storing small amounts of data on the client side for use in subsequent requests.
Installing Dependencies
First, install cookie-parser.
npm install cookie-parserConfiguring Cookies
Next, configure the cookie-parser middleware in your NestJS application.
import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import * as cookieParser from 'cookie-parser';
async function bootstrap() {
const app = await NestFactory.create(AppModule);
// Configure cookie-parser middleware
app.use(cookieParser());
await app.listen(3000);
}
bootstrap();Setting Cookies
Once the cookie-parser middleware is configured, you can use the res object in controllers to set cookies.
import { Controller, Get, Res } from '@nestjs/common';
@Controller()
export class AppController {
@Get('/set-cookie')
setCookie(@Res() res) {
res.cookie('username', 'john_doe', { maxAge: 900000, httpOnly: true });
res.send('Cookie has been set!');
}
}Reading Cookies
You can also use the req object in controllers to read cookies.
import { Controller, Get, Req } from '@nestjs/common';
@Controller()
export class AppController {
@Get('/get-cookie')
getCookie(@Req() req) {
const username = req.cookies.username;
return { username };
}
}Deleting Cookies
To delete a cookie, set its expiration date to a past time.
import { Controller, Get, Res } from '@nestjs/common';
@Controller()
export class AppController {
@Get('/delete-cookie')
deleteCookie(@Res() res) {
res.clearCookie('username');
res.send('Cookie has been deleted!');
}
}Additional Configuration Options
Cookies offer various configuration options, such as maxAge, httpOnly, secure, etc. Here are some common options:
maxAge: The maximum lifetime of the cookie (in milliseconds).httpOnly: If set totrue, the cookie cannot be accessed by JavaScript (enhances security).secure: If set totrue, the cookie is only sent over secure connections (HTTPS).sameSite: Controls whether the cookie is sent with cross-site requests. Can be set to'strict','lax', or'none'.
import { Controller, Get, Res } from '@nestjs/common';
@Controller()
export class AppController {
@Get('/set-cookie')
setCookie(@Res() res) {
res.cookie('username', 'john_doe', {
maxAge: 900000,
httpOnly: true,
secure: true, // Should be true in production
sameSite: 'strict',
});
res.send('Cookie has been set!');
}
}HTTP Module
In NestJS, the HTTP module (@nestjs/axios) provides a convenient way to make HTTP requests. This is commonly used to fetch data from external services or interact with other microservices.
Installing Dependencies
First, install @nestjs/axios.
npm install --save @nestjs/axiosImporting the HTTP Module
Next, import the HttpModule in your module file.
import { Module } from '@nestjs/common';
import { HttpModule } from '@nestjs/axios';
import { CatsController } from './cats.controller';
import { CatsService } from './cats.service';
@Module({
imports: [HttpModule],
controllers: [CatsController],
providers: [CatsService],
})
export class CatsModule {}Using HttpService
Inject the HttpService into a service and use it to make HTTP requests.
import { Injectable } from '@nestjs/common';
import { HttpService } from '@nestjs/axios';
@Injectable()
export class CatsService {
constructor(private readonly httpService: HttpService) {}
async fetchCats(): Promise<any> {
const { data } = await this.httpService.get('https://api.example.com/cats').toPromise();
return data;
}
}Calling the Service in a Controller
Call the service method in a controller to fetch data and return it to the client.
import { Controller, Get } from '@nestjs/common';
import { CatsService } from './cats.service';
@Controller('cats')
export class CatsController {
constructor(private readonly catsService: CatsService) {}
@Get()
async getCats() {
return await this.catsService.fetchCats();
}
}Additional Configuration Options
@nestjs/axios provides various configuration options to customize HTTP request behavior, such as setting timeouts or adding default headers.
import { Module } from '@nestjs/common';
import { HttpModule } from '@nestjs/axios';
import { CatsController } from './cats.controller';
import { CatsService } from './cats.service';
@Module({
imports: [
HttpModule.register({
timeout: 5000,
maxRedirects: 5,
}),
],
controllers: [CatsController],
providers: [CatsService],
})
export class CatsModule {}Error Handling
When making HTTP requests, you may need to handle errors. This can be achieved by catching exceptions.
import { Injectable } from '@nestjs/common';
import { HttpService } from '@nestjs/axios';
@Injectable()
export class CatsService {
constructor(private readonly httpService: HttpService) {}
async fetchCats(): Promise<any> {
try {
const { data } = await this.httpService.get('https://api.example.com/cats').toPromise();
return data;
} catch (error) {
console.error('Error fetching cats:', error);
throw new Error('Failed to fetch cats');
}
}
}
