Progressive Web Apps are easy to build, as developers need to be familiar with standard web technologies. It takes less time to develop than any mobile app. But it has a unique architecture than other traditional websites.
PWAs is not only a feature-rich technology to create applications but also four technical components that support features. They are:
- Web App Manifest File is a JSON file that gives progressive apps an appealing appearance. The manifest file controls the display of the app.
- Service Workersupports key features such as offline work mode, background syncs, and push notifications.
- Application Shell Architecture comprises core elements to make the application run without connection.
- Transport Security Layer (TSL) secures data transactions between two applications. TSL protocol installs an SSL certificate on a server for secure URLs.
Among all of them, the Service worker plays a vital role in the growth of PWA technology. To get familiar with Progressive web apps, you should first learn about service workers. This blog is a guide about service workers – what it is, how it works, and why it is vital for PWA?
Table of Contents
Understanding Service Worker
A service worker is a JavaScript file that runs independently from the browser. It can help manage PWA features, including offline mode, push notifications, etc. Service workers can control Websites and allow them to access hardware features.
How does it work?
Service workers respond when the user interacts with the application. It runs only on processing a specific event. It works as a middle layer between the browser and the server that handles the outgoing network requests.
However, the service worker receives the events when it is active. All the events (fetch, sync, and push) make progressive web app features available.
How do Service Workers help PWAs?
A service worker is the foundation of web applications. Without this, many PWA features will not work. Look at what a service worker provides:
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Offline Mode:
During registration, service workers cache the required content to be served later. This feature makes PWA websites capable of working offline. Also, users can browse and see all the cached content.
🔥 Previously, this offline access feature was not available for websites. Due to its many drawbacks, App cache was the issue behind this. The purpose of service workers is to eliminate this problem.
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Native Push Notifications
Push notifications help you gain customers by re-engaging them through your website content. PWA sites can use push notifications as an efficient tool to send prompt updates to users. Progressive web apps can send notifications even when they are offline. -
Background synchronization
The service worker supports all the advanced features of the PWA site. The website will not be able to process any user action until a stable internet connection is established. Suppose the user is downloading before the connection gets lost.
As soon as the service is restored, the required files will start downloading. It allows mobile web apps to update automatically when the Internet connection is back.
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Outstanding Performance
Service workers help to improve the PWA performances. It enhances the user experience with the caching process. Users can visit the PWA and browse the content even in critical network conditions. It increases web page conversions and boosts your website’s SERP rankings.
A service worker improves the caching performance of a website, giving developers complete control over the process. If you want to measure the real-world performance of service workers, look at this recent Google study.
Some Service Workers Limitations
Since you know that a service worker is an API that runs separately from the browser. Also, it has some constraints that may face during the PWA development process:
- HTTPS protocol: only HTTPS-encrypted websites can run service workers.
- LocalStorage, DOM, and the window are not accessible.
- Limited Scope: Service workers can access only the current directory (and sub-directories) where the service-worker.js is saved.
- Asynchronous Service workers use promise-based APIs.
How to use Service Worker in your browser?
You may get the knowledge that a Service worker is an event-based component of PWA. A service worker has its lifecycle. To activate service workers in apps, you need to follow these three steps:
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Register the Service Worker
This first step is crucial to installing a service worker in the backend. Otherwise, the browser can’t locate the service worker. If the browser supports the API, it will register the service worker quickly using the serviceworkerContainer.register () method. -
Install the Service Worker
After finding the Service worker API in the browser, the next step is installation. In this phase, the service worker does the caching process. You can use CacheAPI to cache the content when PWA is offline. -
Activate the Service Worker
If you successfully install the service worker, it is time for the activation process. You make sure that no service worker is currently controlling the web pages while activating them.
The Bottom Line
Now, you understand service worker is a crucial step for web apps to run smoothly. It avails all the app-like features for users to access. PWA is emerging as a powerful tool for creating mobile web apps. It is the right time to create your very first web app. To know more about PWA benefits, check out our previous article “ how can PWA help your business?”
