Aaron was kind enough to write the foreword to my new book Going Offline. Here it is in full.
In Going Offline, Jeremy Keith breaks down heady concepts into approachable prose and easy-to-follow code examples. He also points out service worker gotchas and shows you how to deftly avoid them. Invest a scant few hours with this book, and you’ll gain a solid understanding of how to put this new technology to work for you right away. No, really—within fifteen to twenty minutes of putting it down.
It’s so great to see the initial UX work that James and I prototyped in a design sprint come to fruition in the form of a progressive web app!
In the case of this web-app, if the tablets go offline, they will still store all the transactions that are made by customers. Once the tablet comes back online, it will sync it back up to the server. That is, essentially, what a Progressive Web App is — a kind of a website with a few more security and, most importantly, offline features.
A good hands-on introduction to service workers from Mariko.
Here’s a Github issue that turned into a good philosophical debate on how to build a progressive web app: should you enhance your existing site or creating a separate URL?
(For the record: I’m in favour of enhancing.)
Welcoming Progressive Web Apps to Microsoft Edge and Windows 10 - Microsoft Edge Dev BlogMicrosoft Edge Dev Blog
It’s really great to hear about how Microsoft will be promoting progressive web apps as first-class citizens …but it’s really unhelpful that they’re using this fudgy definition:
Progressive Web Apps are just great web sites that can behave like native apps—or, perhaps, Progressive Web Apps are just great apps, powered by Web technologies and delivered with Web infrastructure.
Although they also give a more technical definition:
Technologically speaking, PWAs are web apps, progressively enhanced with modern web technologies (Service Worker, Fetch networking, Cache API, Push notifications, Web App Manifest) to provide a more app-like experience.
Nice try, slipping notifications in there like that, but no. No, no, no. Let’s not fool ourselves into thinking that one of the most annoying “features” of native apps is even desirable on the web.
If you want to use notifications, fine. But they are absolutely not a requirement for a progressive web app.
(A responsive design, on the other hand, totally is.)
Here’s an interesting insight on how WebKit is going to handle the cleanup of unused service workers and caches:
Service worker and Cache API stored information will grow as a user is browsing content. To keep only the stored information that is useful to the user, WebKit will remove unused service worker registrations after a period of a few weeks. Caches that do not get opened after a few weeks will also be removed.
Squee! The next time there’s an update for OS X and iOS, Safari will magically have service worker support! Not only that, but Safari on iOS will start using the information in web app manifests for adding to home screen.
That’s an impressive turnaround.
Well, that escalated quickly! Service workers are now available in Safari’s Technology Preview, which means it won’t be long before it lands in Safari proper.
Everything offline’s coming up Milhouse!
This looks interesting—a new book by Dean Hume all about progressive web apps. A few chapters are available to download.
There’s a lot of misinformation on the internet as to how to build a PWA and how “appy” and SPA-y one must be.
This simply isn’t true. Disappointingly, It is what most of the documentation, blog posts and public discourse seem to imply.
I’m so, so happy to see some pushback against the misinformation that progressive web apps automatically imply client-side rendered single page apps built from scratch. There’s so much value to be had in turbo-charging an existing site into a progressive web app.
But what we don’t need is yet another TLA like Alien Web Apps.
You can use
navigator.storage.estimate() to get a (vague) idea of how much space is available on a device for your service worker caches.
Two of my favourite things together at last: pattern libraries and service workers. Infusion is a tool for generating pattern libraries that also work offline.
Thinking about it, it makes total sense that a pattern library should be a progressive web app.
There are some great service worker optimisation tips in these slides.
Along the lines of John’s recent post, Henrik makes the business case for progressive web apps.
He also points out how they can be much better than native apps for controlling hardware.
They can be up and running in a fraction of the time whether or not they were already “installed” and unlike “apps” can be saved as an app on the device at the user’s discretion!
Essentially they’re really great for creating “ad hoc” experiences that can be “cold started” on a whim nearly as fast as if it were already installed.
A fantastic piece by Aaron who—once again—articulates what I’ve been thinking:
Your site—every site—should be a PWA.
He clearly explains the building blocks of progressive web apps—HTTPS, a manifest file, and a service worker—before describing different scenarios for different kinds of sites:
Progressive Web Apps may seem overly technical or beyond the needs of your project, but they’re really not. They’re just a shorthand for quality web experiences—experiences that can absolutely make a difference in our users’ lives.
Jason lists the stages of gradually turning the Cloud Four site into a progressive web app:
And you can just keep incrementally adding and tweaking:
You don’t have to wait to bundle up a binary, submit it to an app store, and wait for approval before your customers benefit.
This is a smart way to queue up POST submissions for later if the user is offline. It’s not as powerful as background sync (because it requires the user to revisit your site) but it’s a good fallback for browsers that support service workers but don’t yet support background sync