Angular 14 : How to Enable HMR in Your Development Server

Angular is a popular framework for building web applications, and its development server provides features for fast iteration during development. One such feature is Hot Module Replacement (HMR), which allows for fast reloading of components in your application without having to refresh the entire page. This can greatly speed up the development process and make it more enjoyable.

In this tutorial, we’ll go over how to enable HMR in your Angular development server, and what it can do for your development workflow. Whether you’re a seasoned Angular developer or just starting out, you’ll find this guide helpful in getting the most out of HMR in your Angular projects.

Step 1: Install the @angular/hot-loader package:

The first step is to install the @angular/hot-loader package. This package provides the necessary tools to enable HMR in your Angular development server. You can install it by running the following command in your terminal:

npm install @angular/hot-loader

Step 2: Update the scripts in your package.json file

Next, you need to update the scripts in your package.json file to include the HMR flag. You should add the following line to your start script:

"start": "ng serve --hmr"

Step 3: Update the code in your main.ts file

In order for HMR to work, you need to update the code in your main.ts file. Replace the existing code with the following:

import { enableProdMode } from '@angular/core';
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';

import { AppModule } from './app/app.module';
import { environment } from './environments/environment';

if (environment.production) {
  enableProdMode();
}

platformBrowserDynamic().bootstrapModule(AppModule)
  .catch(err => console.error(err));

if (module['hot']) {
  module['hot'].accept();
}

Step 4: Start the development server

Finally, you can start the development server by running the following command in your terminal:

npm run start

Conclusion:

By following these steps, you can enable HMR in your Angular development server and speed up your development process. With HMR, you can see changes to your application in real-time without having to reload the entire page, making it easier to make and test updates.

Category: Angular