Book Image

Progressive Web Application Development by Example

By : Love
Book Image

Progressive Web Application Development by Example

By: Love

Overview of this book

Are you a developer that wants to create truly cross-platform user experiences with a minimal footprint, free of store restrictions and features customers want? Then you need to get to grips with Progressive Web Applications (PWAs), a perfect amalgamation of web and mobile applications with a blazing-fast response time. Progressive Web Application Development by Example helps you explore concepts of the PWA development by enabling you to develop three projects, starting with a 2048 game. In this game, you will review parts of a web manifest file and understand how a browser uses properties to define the home screen experience. You will then move on to learning how to develop and use a podcast client and be introduced to service workers. The application will demonstrate how service workers are registered and updated. In addition to this, you will review a caching API so that you have a firm understanding of how to use the cache within a service worker, and you'll discover core caching strategies and how to code them within a service worker. Finally, you will study how to build a tickets application, wherein you’ll apply advanced service worker techniques, such as cache invalidation. Also, you'll learn about tools you can use to validate your applications and scaffold them for quality and consistency. By the end of the book, you will have walked through browser developer tools, node modules, and online tools for creating high-quality PWAs.
Table of Contents (12 chapters)

How the service worker cache works

The service worker sits between the browser and the network. By adding a fetch event handler, you can determine how the request is handled. All network requests pass through the service worker's fetch event handler:

This gives you a hook, or way to inject logic into the workflow, to intercept requests and determine how and where the response is returned.

With the service worker, you can do the following:

  • Pass the request to the network, the traditional method
  • Return a cached response, bypassing the network altogether
  • Create a custom response

When the network fails, you can program the service worker to return a response from the cache, even if it is a fallback response. Because the service worker can return responses from the cache, your pages can load instantly if they are cached:

In the preceding diagram, the service worker is programmed...