Tags: web



Wednesday, May 24th, 2017

The Apophenic Machine — Real Life

To navigate the web is to beat a path through a labyrinth of links left by others, and to thereby create associative links yourself, unspooling them like a guiding thread onto a floor already carpeted with such connections. Each thread of connection is unique, individualized: everyone draws their own map of the network as they navigate it.

Tuesday, May 23rd, 2017

Going offline at Indie Web Camp Düsseldorf

I’ve just come back from a ten-day trip to Germany. The trip kicked off with Indie Web Camp Düsseldorf over the course of a weekend.

IndieWebCamp Düsseldorf 2017

Once again the wonderful people at Sipgate hosted us in their beautiful building, and once again myself and Aaron helped facilitate the two days.

IndieWebCamp Düsseldorf 2017

Saturday was the BarCamp-like discussion day. Plenty of interesting topics were covered. I led a session on service workers, and that’s also what I decided to work on for the second day—that’s when the talking is done and we get down to making.

IndieWebCamp Düsseldorf 2017 IndieWebCamp Düsseldorf 2017 IndieWebCamp Düsseldorf 2017 IndieWebCamp Düsseldorf 2017

I like what Ethan is doing on his offline page. He shows a list of pages that have been cached, but instead of just listing URLs, he shows a title and description for each page.

I’ve already got a separate cache for pages that gets added to as the user browses around my site. I needed to figure out a way to store the metadata for those pages so that I could then display it on the offline page. I came up with a workable solution, and interestingly, it involved no changes to the service worker script at all.

When you visit any blog post, I put metadata about the page into localStorage (after first checking that there’s an active service worker):

if (navigator.serviceWorker && navigator.serviceWorker.controller) {
  window.addEventListener('load', function() {
    var data = {
      "title": "A minority report on artificial intelligence",
      "description": "Revisiting Spielberg’s films after a decade and a half.",
      "published": "May 7th, 2017",
      "timestamp": "1494171049"

In my case, I’m outputting the metadata from the server, but you could just as easily grab some from the DOM like this:

var data = {
  "title": document.querySelector("title").innerText,
  "description": document.querySelector("meta[name='description']").getAttribute("contents")

Meanwhile in my service worker, when you visit that same page, it gets added to a cache called “pages”. Both localStorage and the cache API are using URLs as keys. I take advantage of that on my offline page.

The nice thing about writing JavaScript on my offline page is that I know the page will only be seen by modern browsers that support service workers, so I can use all sorts of fancy from ES6, or whatever we’re calling it now.

I start by looping through the keys of the “pages” cache (that’s right—the cache API isn’t just for service workers; you can access it from any script). Then I check to see if there is a corresponding localStorage key with the same string (a URL). If there is, I pull the metadata out of local storage and add it to an array called browsingHistory:

const browsingHistory = [];
.then( cache => {
  .then(keys => {
    keys.forEach( request => {
      let data = JSON.parse(localStorage.getItem(request.url));
        if (data) {
          data['url'] = request.url;

Then I sort the list of pages in reverse chronological order:

browsingHistory.sort( (a,b) => {
  return b.timestamp - a.timestamp;

Now I loop through each page in the browsing history list and construct a link to each URL, complete with title and description:

let markup = '';
browsingHistory.forEach( data => {
  markup += `
<h2><a href="${ data.url }">${ data.title }</a></h2>
<p>${ data.description }</p>
<p class="meta">${ data.published }</p>

Finally I dump the constructed markup into a waiting div in the page with an ID of “history”:

let container = document.getElementById('history');
container.insertAdjacentHTML('beforeend', markup);

All those steps need to be wrapped inside the then clause attached to caches.open("pages") because the cache API is asynchronous.

There you have it. Now if you’re browsing adactio.com and your network connection drops (or my server goes offline), you can choose from a list of pages you’ve previously visited.

The current situation isn’t ideal though. I’ve got a clean-up operation in my service worker to limit the number of items stored in my “pages” cache. The cache never gets bigger than 35 items. But there’s no corresponding clean-up of metadata stored in localStorage. So there could be a lot more bits of metadata in local storage than there are pages in the cache. It’s not harmful, but it’s a bit wasteful.

I can’t do a clean-up of localStorage from my service worker because service workers can’t access localStorage. There’s a very good reason for that: the localStorage API is synchronous, and everything that happens in a service worker needs to be asynchronous.

Service workers can access indexedDB: it’s asynchronous. I could use indexedDB instead of localStorage, but I’m not a masochist. My best bet would be to use the localForage library, which wraps indexedDB in the simple syntax of localStorage.

Maybe I’ll do that at the next Homebrew Website Club here in Brighton.

Amber Wilson: IndieWebCamp

Amber’s report from Indie Web Camp Nuremberg last week. I was blown away by how much she got done in one day.

Thursday, May 11th, 2017

Programming Design Systems

This is a really intriguing book that combines design theory and programming—learn about contrast, colour, and shapes, with each lesson supported by code examples.

It’s still a work in progress but the whole thing is online for free. Yay for web books!

Saturday, May 6th, 2017

ongoing by Tim Bray · Still Blogging in 2017

This really resonates with me. Tim Bray duly notes that people are writing on Medium, and being shunted towards native apps, and that content is getting centralised at Facebook and other hubs, and then he declares:

But I don’t care.


Any­how, I’m not go­ing away.


Friday, April 28th, 2017

A Case for Progressive Web Applications in 2017

If your company is or is planning on doing business in emerging markets, architecting your web applications for performance through progressive enhancements is one easy way to drastically improve accessibility, retention, and user experience.

This article uses “progressive enhancement” and “progressive web app” interchangeably, which would be true in an ideal world. This is the first of a three part series, and it sounds like it will indeed document how to take an existing site and enhance it into a progressive web app—a strategy I much prefer to creating a separate silo that only works for a subset of devices (the app-shell model being pushed by Google).

Thursday, April 27th, 2017


This is a great free service for doing a bit of performance monitoring on your site. It uses WebPageTest and you do all the set up via a Github repo that then displays the results using Github Pages.

It won’t give you the power or control of Calibre but it’s a handy option for smaller sites. Here are the results for adactio.com running on a Moto G over 3G.

Obrigado, Eduardo!

Tuesday, April 18th, 2017

Progressive Web Apps - ILT  |  Web  |  Google Developers

A step-by-step guide to building progressive web apps. It covers promises, service workers, fetch, and cache, but seeing as it’s from Google, it also pushes the app-shell model.

This is a handy resource but I strongly disagree with some of the advice in the section on architectures (the same bit that gets all swoonsome for app shells):

Start by forgetting everything you know about conventional web design, and instead imagine designing a native app.

Avoid overly “web-like” design.

What a horribly limiting vision for the web! After all that talk about being progressive and responsive, we’re told to pretend we’re imitating native apps on one device type.

What’s really disgusting is the way that the Chrome team are withholding the “add to home screen” prompt from anyone who dares to make progressive web apps that are actually, y’know …webby.

Sunday, April 16th, 2017

@Mentions from Twitter to My Website

Chris gives a step-by-step walkthrough of enabling webmentions on a Wordpress site.

Tuesday, April 11th, 2017

Reflections on Resilient Web Design - Scott Dawson

I’m genuinely touched that my little web book could inspire someone like this. I absolutely love reading about what people thought of the book, especially when they post on their own site like this.

This book has inspired me to approach web site building in a new way. By focusing on the core functionality and expanding it based on available features, I’ll ensure the most accessible site I can. Resilient web sites can give a core experience that’s meaningful, but progressively enhance that experience based on technical capabilities.

Monday, April 10th, 2017

Recommended Reading: Resilient Web Design, a Free e-Book from Jeremy Keith – WordPress Tavern

A jolly nice review of Resilient Web Design.

After just a few pages in, I could see why so many have read Resilient Web Design all in one go. It lives up to all the excellent reviews.

Tuesday, April 4th, 2017

A bit more on container queries. — Ethan Marcotte

Ethan wrote about container queries on his website. Paul wrote his counter-argument on his website. Now Ethan responds. It’s fun to watch two gentlemen engage in civilised discourse.

Blogs, man. They’re gonna big, I tells ya.

Monday, April 3rd, 2017

Cascading HTML Style Sheets — A Proposal

It’s fascinating to look back at this early proposal for CSS from 1994 and see what the syntax might have been:

A one-statement style sheet that sets the font size of the h1 element:

h1.font.size = 24pt 100%

The percentage at the end of the line indicates what degree of influence that is requested (here 100%).

Thursday, March 30th, 2017

The Analog Web | Jim Nielsen’s Blog

This is wonderful meditation on the history of older technologies that degrade in varied conditions versus newer formats that fall of a “digital cliff”, all tied in to working on the web.

When digital TV fails, it fails completely. Analog TV, to use parlance of the web, degrades gracefully. The web could be similar, if we choose to make it so. It could be “the analog” web in contrast to “the digital” platforms. Perhaps in our hurry to replicate and mirror native platforms, we’re forgetting the killer strength of the web: universal accessibility.

Thursday, March 23rd, 2017

Need to Catch Up on the AMP Debate? | CSS-Tricks

Funnily enough, I led a brown bag lunch discussion about AMP at work just the other day. A lot of it mirrored Chris’s thoughts here. It’s a complicated situation that has lots of people worried.

The Road To Resilient Web Design – Smashing Magazine

Chapter 3 of Resilient Web Design, republished in Smashing Magazine:

In the world of web design, we tend to become preoccupied with the here and now. In “Resilient Web Design“, Jeremy Keith emphasizes the importance of learning from the past in order to better prepare ourselves for the future. So, perhaps we should stop and think more beyond our present moment? The following is an excerpt from Jeremy’s web book.

Wednesday, March 22nd, 2017

Writing on the web

Some people have been putting Paul’s crazy idea into practice.

  • Mike revived his site a while back and he’s been posting gold dust ever since. I enjoy his no-holds-barred perspective on his time in San Francisco.
  • Garrett’s writing goes all the way back to 2005. The cumulative result is two fascinating interweaving narratives—one about his health, another about his business.
  • Charlotte has been documenting her move from Brighton to Sydney. Much as I love her articles about front-end development, I’m liking the slice-of-life updates on life down under even more.
  • Amber has a great way with words. As well as regularly writing on her blog, she’s two-thirds of the way through writing 100 words every day for 100 days.
  • Ethan has been writing about responsive design—of course—but it’s his more personal posts that make me really grateful for his site.
  • Jeffrey and Eric never stopped writing on their own sites. Sure, there’s good stuff on their about web design and development, but it’s the writing about their non-web lives that’s so powerful.

There are more people I could mention …but, to be honest, not that many more. Seems like most people are happy to only publish on Ev’s blog or not at all.

I know not everybody wants to write on the web, and that’s fine. But it makes me sad when people choose not to publish their thoughts because they think no-one will be interested, or that it’s all been said before. I understand where those worries come from, but I believe—no, I know—that they are unfounded.

It’s a world wide web out there. There’s plenty of room for everyone. And I, for one, love reading the words of others.

Monday, March 20th, 2017

Tim Berners-Lee ~ The World Wide Web - YouTube

There’s something very endearing about this docudrama retelling of the story of the web.

Wednesday, March 15th, 2017

Progressive Web App questions

I got a nice email recently from Colin van Eenige. He wrote:

For my graduation project I’m researching the development of Progressive Web Apps and found your offline book called resilient web design. I was very impressed by the implementation of the website and it really was a nice experience.

I’m very interested in your vision on progressive web apps and what capabilities are waiting for us regarding offline content. Would it be fine if I’d send you some questions?

I said that would be fine, although I couldn’t promise a swift response. He sent me four questions. I finally got ‘round to sending my answers…

1. https://resilientwebdesign.com/ is an offline web book (progressive web app). What was the primary reason make it available like this (besides the other formats)?

Well, given the subject matter, it felt right that the canonical version of the book should be not just online, but made with the building blocks of the web. The other formats are all nice to have, but the HTML version feels (to me) like the “real” book.

Interestingly, it wasn’t too much trouble for people to generate other formats from the HTML (ePub, MOBI, PDF), whereas I think trying to go in the other direction would be trickier.

As for the offline part, that felt like a natural fit. I had already done that with a previous book of mine, HTML5 For Web Designers, which I put online a year or two after its print publication. In that case, I used AppCache for the offline functionality. AppCache is horrible, but this use case might be one of the few where it works well: a static book that’s never going to change. Cache invalidation is one of the worst parts of using AppCache so by not having any kinds of updates at all, I dodged that bullet.

But when it came time for Resilient Web Design, a service worker was definitely the right technology. Still, I’ve got AppCache in there as well for the browsers that don’t yet support service workers.

2. What effect you you think Progressive Web Apps will have on content consuming and do you think these will take over the purpose of some Native Apps?

The biggest effect that service workers could have is to change the expectations that people have about using the web, especially on mobile devices. Right now, people associate the web on mobile with long waits and horrible spammy overlays. Service workers can help solve that first part.

If people then start adding sites to their home screen, that will be a great sign that the web is really holding its own. But I don’t think we should get too optimistic about that: for a user, there’s no difference between a prompt on their screen saying “add to home screen” and a prompt on their screen saying “download our app”—they’re equally likely to be dismissed because we’ve trained people to dismiss anything that covers up the content they actually came for.

It’s entirely possible that websites could start taking over much of the functionality that previously was only possible in a native app. But I think that inertia and habit will keep people using native apps for quite some time.

The big exception is in markets where storage space on devices is in short supply. That’s where the decision to install a native app isn’t taken likely (given the choice between your family photos and an app, most people will reject the app). The web can truly shine here if we build lightweight, performant services.

Even in that situation, I’m still not sure how many people will end up adding those sites to their home screen (it might feel so similar to installing a native app that there may be some residual worry about storage space) but I don’t think that’s too much of a problem: if people get to a site via search or typing, that’s fine.

I worry that the messaging around “progressive web apps” is perhaps over-fetishising the home screen. I don’t think that’s the real battleground. The real battleground is in people’s heads; how they perceive the web and how they perceive native.

After all, if the average number of native apps installed in a month is zero, then that’s not exactly a hard target to match. :-)

3. What is your vision regarding Progressive Web Apps?

For me, progressive web apps don’t feel like a separate thing from making websites. I worry that the marketing of them might inflate expectations or confuse people. I like the idea that they’re simply websites that have taken their vitamins.

So my vision for progressive web apps is the same as my vision for the web: something that people use every day for all sorts of tasks.

I find it really discouraging that progressive web apps are becoming conflated with single page apps and the app shell model. Those architectural decisions have nothing to do with service workers, HTTPS, and manifest files. Yet I keep seeing the concepts used interchangeably. It would be a real shame if people chose not to use these great technologies just because they don’t classify what they’re building as an “app.”

If anything, it’s good ol’ fashioned content sites (newspapers, wikipedia, blogs, and yes, books) that can really benefit from the turbo boost of service worker+HTTPS+manifest.

I was at a conference recently where someone was given a talk encouraging people to build progressive web apps but discouraging people from doing it for their own personal sites. That’s a horrible, elitist attitude. I worry that this attitude is being codified in the term “progressive web app”.

4. What is the biggest learning you’ve had since working on Progressive Web Apps?

Well, like I said, I think that some people are focusing a bit too much on the home screen and not enough on the benefits that service workers can provide to just about any website.

My biggest learning is that these technologies aren’t for a specific subset of services, but can benefit just about anything that’s on the web. I mean, just using a service worker to explicitly cache static assets like CSS, JS, and some images is a no-brainer for almost any project.

So there you go—I’m very excited about the capabilities of these technologies, but very worried about how they’re being “sold”. I’m particularly nervous that in the rush to emulate native apps, we end up losing the very thing that makes the web so powerful: URLs.

Sunday, March 12th, 2017

WebPonize - webponize.github.io

A Mac app for converting PNGs and JPEGs to WebP.