service workers

I stumbled upon this site the other day from Mozilla that’s a collection of recipes to get started with a Service Worker — from caching strategies and notifications to providing an offline fallback to your users, this little cookbook has it all.

You can also check out our guide to making a simple site work offline and the offline site that resulted from it.

Jeremy Keith has written a new book all about service workers and offline functionality that releases at the end of the month. The first chapter is posted on A List Apart. Now that the latest versions of iOS and macOS Safari support service workers, I can’t think of a better time to learn about how progressive web apps work under the hood. In fact, here's an example of a simple offline site and a short series on making web apps work offline.

News of Jeremy's book had me going back through his previous book, Resilient Web Design, where I half-remembered this super interesting quote from Chapter 4:

If you build something using web technologies, and someone visits with a web browser, you can’t be sure how many of the web technologies will be supported. It probably won’t be 100%. But it’s also unlikely to be 0%. Some people will visit with iOS devices. Others will visit with Android devices. Some people will get 80% or 90% of what you’ve designed. Others will get just 20%, 30%, or 50%. The web isn’t a platform. It’s a continuum.

I love this idea of the web as a continuum that’s constantly improving and growing over time and so I’m sure Jeremy’s latest book will be just as fun and interesting.

I hadn't considered the fact that if you're fingerprinting your assets (e.g. style.987987090897.css) to take advantage of browser cache, you'll need to update your Service Worker every time you do that. But I guess you've got a build step anyway, so it can be updated in both places:

... we used a NodeJS module called Stacify to automatically create new version numbers in all the places when a file is changed.

A straightforward tutorial by Una Kravets on caching assets and individually requested articles with Service Workers for offline reading.

I'm curious what the best practice will become. It's possible that asking users to click something is it. Also possible: passively caching articles based on recently published, currently viewing, or related to currently viewing.

Mariko Kosaka:

I finally figured out, it's an alien you can invite to live on user's browser.