How to Build a PWA With Angular Service Worker

Progressive Web Apps (PWAs) are web applications that offer a native app-like experience on the web. They allow users to install apps on their devices, work offline, and provide notifications. One of the key components of building a PWA is implementing a Service Worker. In this article, we will walk through the steps to build a PWA using Angular's Service Worker.

Step 1: Setting Up Your Angular Project

Begin by creating a new Angular project if you haven't already. You can use the Angular CLI to set this up. Open your terminal and run:

ng new my-pwa-app

Once your project is created, navigate to the project directory:

cd my-pwa-app

Step 2: Adding the Angular Service Worker

Next, you’ll need to add the Angular Service Worker package to your project. Use the following command:

ng add @angular/pwa

This command will automatically configure your application as a PWA. It will add a Service Worker, along with configurations in the angular.json file and a manifest file for your app.

Step 3: Configuring the Manifest File

The manifest file is essential for defining how your app appears on users’ devices. Open the manifest.webmanifest file, and customize the following properties:

name: The name of your application.
short_name: A shorter version of your app's name.
icons: Provide various sizes of your app's icons.
start_url: The URL that should open when the app is launched.
display: Set it to standalone for a full-screen experience.

Step 4: Implementing the Service Worker

The Service Worker file is automatically generated at src/ngsw-config.json. This file allows you to control the caching of your application’s assets. You can define the behavior for assets like HTML, CSS, JS, and images. Here's a basic example:

{
  "index": "/index.html",
  "assetGroups": [{
    "name": "app",
    "installMode": "prefetch",
    "resources": {
      "files": [
        "/favicon.ico",
        "/index.html",
        "/*.css",
        "/*.js"
      ]
    }
  }]
}

Step 5: Building and Serving Your Application

To see your PWA in action, build your application for production:

ng build --prod

Once the build is complete, serve your application using a local server, such as http-server:

http-server -p 8080 -o

Navigate to http://localhost:8080 in your browser, and you should see your PWA running.

Step 6: Testing the PWA Features

To test the PWA capabilities, you can use Google Chrome. Open the Developer Tools (F12 or right-click and select "Inspect"), then go to the "Application" tab. Here, you should see that your Service Worker is registered and the manifest is being recognized. Additionally, you can test offline capabilities by disconnecting from the internet and refreshing the page.

Step 7: Deploying Your PWA

Finally, deploy your PWA to a web hosting service that supports HTTPS, as Service Workers require secure origins. Services like Firebase Hosting, Vercel, or Netlify are great options for hosting your PWA.

By following these steps, you can successfully build and deploy a Progressive Web App using Angular Service Worker, enhancing user experience with a fast, reliable, and installable web application.

How to Build a PWA With Angular Service Worker