Tags: caching

Blog service workers and the chicken and the egg

This is a great little technique from Remy: when a service worker is being installed, you make sure that the page(s) the user is first visiting get added to a cache.

Offline listings

This is brilliant technique by Remy!

If you’ve got a custom offline page that lists previously-visited pages (like I do on my site), you don’t have to choose between localStorage or IndexedDB—you can read the metadata straight from the HTML of the cached pages instead!

This seems forehead-smackingly obvious in hindsight. I’m totally stealing this.

Self-Host Your Static Assets – CSS Wizardry

Trust no one! Harry enumerates the reason why you should be self-hosting your assets (and busts some myths along the way).

There really is very little reason to leave your static assets on anyone else’s infrastructure. The perceived benefits are often a myth, and even if they weren’t, the trade-offs simply aren’t worth it. Loading assets from multiple origins is demonstrably slower.

Distinguishing cached vs. network HTML requests in a Service Worker | Trys Mudford

Less than 24 hours after I put the call out for a solution to this gnarly service worker challenge, Trys has come up with a solution.

Tuning Performance for New and “Old” Friends | Filament Group, Inc., Boston, MA

This is a really clever technique from Scott that he unveiled at An Event Apart in Seattle. It uses a header sent by a service worker to distinguish between returning and new visitors—much neater than relying on a cookie. I’ve updated my service worker on The Session to use this technique now.

Cache-Control for Civilians – CSS Wizardry

Harry breaks down cache-control headers into steps that even I can understand. I’ll be using this a reference for sure.

Introducing Background Fetch  |  Web  |  Google Developers

I’m going to have to read through this article by Jake a few times before I begin to wrap my head around this background fetch thing, but it looks like it would be perfect for something like the dConstruct Audio Archive, where fairly large files can be saved for offline listening.

PushAPI without Notifications | Seblog

Remember when I wrote about using push without notifications? Sebastiaan has written up the details of the experiment he conducted at Indie Web Camp Berlin.

Push and ye shall receive | CSS-Tricks

Imagine a PWA podcast app that works offline and silently receives and caches new podcasts. Sweet. Now we need a permissions model that allows for silent notifications.

Inlining or Caching? Both Please! | Filament Group, Inc., Boston, MA

This just blew my mind! A fiendishly clever pattern that allows you to inline resources (like critical CSS) and cache that same content for later retrieval by a service worker.

Crazy clever!

Thoughts on Offline-first | Trys Mudford

Service Workers have such huge potential power, and I feel like we (developers on the web) have barely scratched the surface with what’s possible.

Needless to say, I couldn’t agree more!

Trys is thinking through some of the implicatons of service workers, like how we refresh stale content, and how we deal with slow networks—something that’s actually more of a challenge than dealing with no network connection at all.

There’s some good food for thought here.

I’m so excited to see how we can use Service Workers to improve the web.

Offline Content with Service Worker — Chris Ruppel

A step-by-step walkthrough of a really useful service worker pattern: allowing users to save articles for offline reading at the click of a button (kind of like adding the functionality of Instapaper or Pocket to your own site).

On HTTPS and Hard Questions - TimKadlec.com

A great post by Tim following on from the post by Eric I linked to last week.

Is a secure site you can’t access better than an insecure one you can?

He rightly points out that security without performance is exlusionary.

…we’ve made a move to increase the security of the web by doing everything we can to get everything running over HTTPS. It’s undeniably a vital move to make. However this combination—poor performance but good security—now ends up making the web inaccessible to many.

Security. Performance. Accessibility. All three matter.

Securing Web Sites Made Them Less Accessible – Eric’s Archived Thoughts

This is a heartbreaking observation by Eric. He’s not anti-HTTPS by any stretch, but he is pointing out that caching servers become a thing of the past on a more secure web.

Can we do anything? For users of up-to-date browsers, yes: service workers create a “good” man in the middle that sidesteps the HTTPS problem, so far as I understand. So if you’re serving content over HTTPS, creating a service worker should be one of your top priorities right now, even if it’s just to do straightforward local caching and nothing fancier.

When 7 KB Equals 7 MB - Cloud Four

I remember Jason telling me about this weird service worker caching behaviour a little while back. This piece is a great bit of sleuthing in tracking down the root causes of this strange issue, followed up with a sensible solution.

Fresher service workers, by default

“Ah, this is good news!”, I thought, reading this update about how service worker scripts won’t be cached.

And that was the moment when I realised what an utter nerd I had become.

Network Information API

It looks like this is landing in Chrome. The navigator.connection.type property will allow us to progressively enhance based on connection type:

A web application that makes use of a service worker to cache resources during installation might have different bundles of assets that it might cache: a list of crucial assets that are cached unconditionally, and a bundle of larger, optional assets that are only cached ahead of time when navigator.connection.type is 'ethernet' or 'wifi'.

There are potential security issues around fingerprinting that are addressed in this document.

How much storage space is my Progressive Web App using? | Dean Hume

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.

It’s not working! Should I blame caching?

Finally, the answer to one of the two hard questions in computer science.

Offline Web Applications | Udacity

This is a free online video course recorded by Jake a couple of years back. It’s got a really good step-by-step introduction to service workers, delivered in Jake’s typically witty way. Some of the details are a bit out of date, and I must admit that I bailed when it got to IndexedDB, but I highly recommend giving this a go.

There’s also a free course on web accessibility I’m planning to check out.