Using NestJS for Server-Side Rendering (SSR)

In the rapidly evolving landscape of web development, Server-Side Rendering (SSR) has proven to be a powerful strategy to enhance the performance and SEO capabilities of web applications. While frameworks like Next.js and Nuxt.js are often top of mind for SSR in React and Vue.js applications respectively, it’s essential to note that NestJS, a progressive Node.js framework, also provides robust support for server-side rendering, particularly with Angular applications.

In this article, we’ll explore how you can leverage NestJS for SSR. We’ll cover the integration with Angular Universal and touch on why you might opt to use NestJS for rendering your front-end from the server side.

Why Server-Side Rendering?

Before diving into implementation, let’s understand why SSR can be beneficial:

1. Improved Performance: By rendering pages on the server-side, users receive fully rendered pages straight from the server, leading to faster initial load times.
2. SEO Benefits: Search engine bots can better index content that is pre-rendered on the server, enhancing the SEO of your application.
3. Improved Accessibility: Users experience quicker load times and less flicker, creating a smoother user experience.

Prerequisites

To follow this guide, you’ll need:

• Basic knowledge of NestJS and Angular
• Node.js installed on your machine
• An Angular application that you wish to render from the server

Setting Up NestJS for SSR

Step 1: Create a New NestJS Project

Start by creating a new NestJS project (if you haven’t already). You can do this using the Nest CLI:

npm i -g @nestjs/cli
nest new server-side-rendering-example
cd server-side-rendering-example

Step 2: Integrate Angular Universal

Angular Universal is a technology that allows Angular applications to be server-rendered. Adding it is straightforward:

ng add @nguniversal/express-engine

This command modifies the existing Angular application to support SSR using Express. Since NestJS can integrate with Express, we’ll be able to leverage this setup.

Step 3: Modify Your NestJS Application

NestJS applications are built around modules and are highly pluggable. Here’s how you can modify your NestJS app to use SSR:

1. Install Node Package

Ensure you install @nguniversal/express-engine via ng add as shown above. This command modifies the Angular project by adding necessary dependencies and files such as a server module and a server.ts file used to bootstrap your application.

1. Set Up Express Engine

Ensure that your NestJS main entry file (main.ts) uses the Express engine to serve the Angular application:

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { join } from 'path';
import { ngExpressEngine } from '@nguniversal/express-engine';
import * as express from 'express';

async function bootstrap() {
  const server = express();

  server.engine('html', ngExpressEngine({
    bootstrap: AppModule,
  }));

  server.set('view engine', 'html');
  server.set('views', join(__dirname, '../browser'));

  const app = await NestFactory.create(AppModule, { express: server });

  await app.listen(4000);
}

bootstrap();

1. Build the Application

You need to build both the client and server parts of your application. Use Angular CLI to achieve this:

npm run build:ssr

This will generate a dist folder containing both the server and client builds.

Step 4: Serve the Application

With both the client and server built, you can now serve your application:

node dist/<your-server-file>.js

This will start your server on the specified port, rendering Angular pages server-side before sending them to the client.

Advantages of Using NestJS for SSR

Using NestJS for SSR provides several benefits:

• Unified Backend and Frontend Development: By using NestJS with Angular Universal, both your client and server share a cohesive architecture.
• Modular Architecture: NestJS’s modular approach makes it easy to manage complex applications and promotes scalable practices.
• Strongly Typed: Written in TypeScript, NestJS enables strong typing, reducing bugs and improving IDE support.
• Decorator-based Syntax: The use of decorators in NestJS and Angular makes it easy to read and maintain code.

Final Thoughts

NestJS’s ability to integrate with Angular Universal provides a great way to implement server-side rendering in a type-safe and modular fashion. While frameworks like Next.js are leading in terms of community size and plugins for SSR with frameworks like React, the combination of NestJS and Angular should not be overlooked, especially if your team is already invested in Angular for frontend development.

As a developer, understanding different SSR solutions can equip you to make informed choices for your projects, potentially improving your web application’s load times, SEO, and overall user experience. Give NestJS with SSR a try on your next project and experience its powerful features firsthand.