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Preview: Adactio

Adactio: Journal

The online journal of Jeremy Keith, an author and web developer living and working in Brighton, England.


Looking beyond launch

Thu, 19 Jan 2017 15:35:07 GMT

It’s all go, go, go at Clearleft while we’re working on a new version of our website …accompanied by a brand new identity. It’s an exciting time in the studio, tinged with the slight stress that comes with any kind of unveiling like this.

I think it’s good to remember that this is the web. I keep telling myself that we’re not unveiling something carved in stone. Even after the launch we can keep making the site better. In fact, if we wait until everything is perfect before we launch, we’ll probably never launch at all.

On the other hand, you only get one chance to make a first impression, right? So it’s got to be good …but it doesn’t have to be done. A website is never done.

I’ve got to get comfortable with that. There’s lots of things that I’d like to be done in time for launch, but realistically it’s fine if those things are completed in the subsequent days or weeks.

Adding a service worker and making a nice offline experience? I really want to do that …but it can wait.

What about other performance tweaks? Yes, we’ll to try have every asset—images, fonts—optimised …but maybe not from day one.

Making sure that each page has good metadata—Open Graph? Twitter Cards? Microformats? Maybe even AMP? Sure …but not just yet.

Having gorgeous animations? Again, I really want to have them but as Val rightly points out, animations are an enhancement—a really, really great enhancement.

If anything, putting the site live before doing all these things acts as an incentive to make sure they get done.

So when you see the new site, if you view source or run it through Web Page Test and spot areas for improvement, rest assured we’re on it.

Making Resilient Web Design work offline

Wed, 11 Jan 2017 18:59:11 GMT

I’ve written before about taking an online book offline, documenting the process behind the web version of HTML5 For Web Designers. A book is quite a static thing so it’s safe to take a fairly aggressive offline-first approach. In fact, a static unchanging book is one of the few situations that AppCache works for. Of course a service worker is better, but until AppCache is removed from browsers (and until service worker is supported across the board), I’m using both. I wouldn’t recommend that for most sites though—for most sites, use a service worker to enhance it, and avoid AppCache like the plague. For Resilient Web Design, I took a similar approach to HTML5 For Web Designers but I knew that there was a good chance that some of the content would be getting tweaked at least for a while. So while the approach is still cache-first, I decided to keep the cache fairly fresh. Here’s my service worker. It starts with the usual stuff: when the service worker is installed, there’s a list of static assets to cache. In this case, that list is literally everything; all the HTML, CSS, JavaScript, and images for the whole site. Again, this is a pattern that works well for a book, but wouldn’t be right for other kinds of websites. The real heavy lifting happens with the fetch event. This is where the logic sits for what the service worker should do everytime there’s a request for a resource. I’ve documented the logic with comments: // Look in the cache first, fall back to the network // CACHE // Did we find the file in the cache? // If so, fetch a fresh copy from the network in the background // NETWORK // Stash the fresh copy in the cache // NETWORK // If the file wasn't in the cache, make a network request // Stash a fresh copy in the cache in the background // OFFLINE // If the request is for an image, show an offline placeholder // If the request is for a page, show an offline message So my order of preference is: Try the cache first, Try the network second, Fallback to a placeholder as a last resort. Leaving aside that third part, regardless of whether the response is served straight from the cache or from the network, the cache gets a top-up. If the response is being served from the cache, there’s an additional network request made to get a fresh copy of the resource that was just served. This means that the user might be seeing a slightly stale version of a file, but they’ll get the fresher version next time round. Again, I think this acceptable for a book where the tweaks and changes should be fairly minor, but I definitely wouldn’t want to do it on a more dynamic site where the freshness matters more. Here’s what it usually likes like when a file is served up from the cache: caches.match(request) .then( responseFromCache => { // Did we find the file in the cache? if (responseFromCache) { return responseFromCache; } I’ve introduced an extra step where the fresher version is fetched from the network. This is where the code can look a bit confusing: the network request is happening in the background after the cached file has already been returned, but the code appears before the return statement: caches.match(request) .then( responseFromCache => { // Did we find the file in the cache? if (responseFromCache) { // If so, fetch a fresh copy from the network in the background event.waitUntil( // NETWORK fetch(request) .then( responseFromFetch => { // Stash the fresh copy in the cache .then( cache => { cache.put(request, responseFromFetch); }); }) ); return responseFromCache; } It’s asynchronous, see? So even though all that network code appears before the return statement, it’s pretty much guaranteed to complete after the cache response has been retu[...]

Going rogue

Thu, 05 Jan 2017 17:33:30 GMT

As soon as tickets were available for the Brighton premiere of Rogue One, I grabbed some—two front-row seats for one minute past midnight on December 15th. No problem. That was the night after the Clearleft end-of-year party on December 14th. Then I realised how dates work. One minute past midnight on December 15th is the same night as December 14th. I had double-booked myself. It’s a nice dilemma to have; party or Star Wars? I decided to absolve myself of the decision by buying additional tickets for an evening showing on December 15th. That way, I wouldn’t feel like I had to run out of the Clearleft party before midnight, like some geek Cinderella. In the end though, I did end up running out of the Clearleft party. I had danced and quaffed my fill, things were starting to get messy, and frankly, I was itching to immerse myself in the newest Star Wars film ever since Graham strapped a VR headset on me earlier in the day and let me fly a virtual X-wing. So, somewhat tired and slightly inebriated, I strapped in for the midnight screening of Rogue One: A Star Wars Story. I thought it was okay. Some of the fan service scenes really stuck out, and not in a good way. On the whole, I just wasn’t that gripped by the story. Ah, well. Still, the next evening, I had those extra tickets I had bought as psychological insurance. “Why not?” I thought, and popped along to see it again. This time, I loved it. It wasn’t just me either. Jessica was equally indifferent the first time ‘round, and she also enjoyed it way more the second time. I can’t recall having such a dramatic swing in my appraisal of a film from one viewing to the next. I’m not quite sure why it didn’t resonate the first time. Maybe I was just too tired. Maybe I was overthinking it too much, unable to let myself get caught up in the story because I was over-analysing it as a new Star Wars film. Anyway, I’m glad that I like it now. Much has been made of its similarity to classic World War Two films, which I thought worked really well. But the aspect of the film that I found most thought-provoking was the story of Galen Erso. It’s the classic tale of an apparently good person reluctantly working in service to evil ends. This reminded me of Mother Night, perhaps my favourite Kurt Vonnegut book (although, let’s face it, many of his books are interchangeable—you could put one down halfway through, and pick another one up, and just keep reading). Mother Night gives the backstory of Howard W. Campbell, who appears as a character in Slaughterhouse Five. In the introduction, Vonnegut states that it’s the one story of his with a moral: We are what we pretend to be, so we must be careful about what we pretend to be. If Galen Erso is pretending to work for the Empire, is there any difference to actually working for the Empire? In this case, there’s a get-out clause for this moral dilemma: by sabotaging the work (albeit very, very subtly) Galen’s soul appears to be absolved of sin. That’s the conclusion of the excellent post on the Sci-fi Policy blog, Rogue One: an ‘Engineering Ethics’ Story: What Galen Erso does is not simply watch a system be built and then whistleblow; he actively shaped the design from its earliest stages considering its ultimate societal impacts. These early design decisions are proactive rather than reactive, which is part of the broader engineering ethics lesson of Rogue One. I know I’m Godwinning myself with the WWII comparisons, but there are some obvious historical precedents for Erso’s dilemma. The New York Review of Books has an in-depth look at Werner Heisenberg and his “did he/didn’t he?” legacy with Germany’s stalled atom bomb project. One generous reading of his actions is that he kept the project going in order to keep scientists from being sent to the front, but made sure that the project was never ambitious enough to actually achieve destructive ends: What the letters reveal are glimpses of Heisenberg’s inner[...]


Wed, 04 Jan 2017 18:27:31 GMT

I left the office one evening a few weeks back, and while I was walking up the street, James Box cycled past, waving a hearty good evening to me. I didn’t see him at first. I was in a state of maximum distraction. For one thing, there was someone walking down the street with a magnificent Irish wolfhound. If that weren’t enough to dominate my brain, I also had headphones in my ears through which I was listening to an audio version of a TED talk by Donald Hoffman called Do we really see reality as it is?

It’s fascinating—if mind-bending—stuff. It sounds like the kind of thing that’s used to justify Deepak Chopra style adventures in la-la land, but Hoffman is deliberately taking a rigorous approach. He knows his claims are outrageous, but he welcomes all attempts to falsify his hypotheses.

I’m not noticing this just from a short TED talk. It’s been one of those strange examples of synchronicity where his work has been popping up on my radar multiple times. There’s an article in Quanta magazine that was also republished in The Atlantic. And there’s a really good interview on the You Are Not So Smart podcast that I huffduffed a while back.

But the most unexpected place that Hoffman popped up was when I was diving down a SETI (or METI) rabbit hole. There I was reading about the Cosmic Call project and Lincos when I came across this article: Why ‘Arrival’ Is Wrong About the Possibility of Talking with Space Aliens, with its subtitle “Human efforts to communicate with extraterrestrials are doomed to failure, expert says.” The expert in question pulling apart the numbers in the Drake equation turned out to be none other than Donald Hoffmann.

A few years ago, at a SETI Institute conference on interstellar communication, Hoffman appeared on the bill after a presentation by radio astronomer Frank Drake, who pioneered the search for alien civilizations in 1960. Drake showed the audience dozens of images that had been launched into space aboard NASA’s Voyager probes in the 1970s. Each picture was carefully chosen to be clearly and easily understood by other intelligent beings, he told the crowd.

After Drake spoke, Hoffman took the stage and “politely explained how every one of the images would be infinitely ambiguous to extraterrestrials,” he recalls.

I’m sure he’s quite right. But let’s face it, the Voyager golden record was never really about communicating with an alien intelligence …it was about how we present ourself.

Vertical limit

Tue, 03 Jan 2017 12:23:31 GMT

When I was first styling Resilient Web Design, I made heavy use of vh units. The vertical spacing between elements—headings, paragraphs, images—was all proportional to the overall viewport height. It looked great! Then I tested it on real devices. Here’s the problem: when a page loads up in a mobile browser—like, say, Chrome on an Android device—the URL bar is at the top of the screen. The height of that piece of the browser interface isn’t taken into account for the viewport height. That makes sense: the viewport height is the amount of screen real estate available for the content. The content doesn’t extend into the URL bar, therefore the height of the URL bar shouldn’t be part of the viewport height. But then if you start scrolling down, the URL bar scrolls away off the top of the screen. So now it’s behaving as though it is part of the content rather than part of the browser interface. At this point, the value of the viewport height changes: now it’s the previous value plus the height of the URL bar that was previously there but which has now disappeared. I totally understand why the URL bar is squirrelled away once the user starts scrolling—it frees up some valuable vertical space. But because that necessarily means recalculating the viewport height, it effectively makes the vh unit in CSS very, very limited in scope. In my initial implementation of Resilient Web Design, the one where I was styling almost everything with vh, the site was unusable. Every time you started scrolling, things would jump around. I had to go back to the drawing board and remove almost all instances of vh from the styles. I’ve left it in for one use case and I think it’s the most common use of vh: making an element take up exactly the height of the viewport. The front page of the web book uses min-height: 100vh for the title. But as soon as you scroll down from there, that element changes height. The content below it suddenly moves. Let’s say the overall height of the browser window is 600 pixels, of which 50 pixels are taken up by the URL bar. When the page loads, 100vh is 550 pixels. But as soon as you scroll down and the URL bar floats away, the value of 100vh becomes 600 pixels. (This also causes problems if you’re using vertical media queries. If you choose the wrong vertical breakpoint, then the media query won’t kick in when the page loads but will kick in once the user starts scrolling …or vice-versa.) There’s a mixed message here. On the one hand, the browser is declaring that the URL bar is part of its interface; that the space is off-limits for content. But then, once scrolling starts, that is invalidated. Now the URL bar is behaving as though it is part of the content scrolling off the top of the viewport. The result of this messiness is that the vh unit is practically useless for real-world situations with real-world devices. It works great for desktop browsers if you’re grabbing the browser window and resizing, but that’s not exactly a common scenario for anyone other than web developers. I’m sure there’s a way of solving it with JavaScript but that feels like using an atomic bomb to crack a walnut—the whole point of having this in CSS is that we don’t need to use JavaScript for something related to styling. It’s such a shame. A piece of CSS that’s great in theory, and is really well supported, just falls apart where it matters most. Update: There’s a two-year old bug report on this for Chrome, and it looks like it might actually get fixed in February. [...]

2016 reading list

Mon, 02 Jan 2017 10:32:38 GMT

I was having a think back over 2016, trying to remember which books I had read during the year. To the best of my recollection, I think that this is the final tally…


  • Endurance by Alfred Lansing
  • The Rational Optimist by Matt Ridley
  • The Real World of Technology by Ursula Franklin
  • Design For Real Life by Eric Meyer and Sara Wachter-Boettcher
  • Practical SVG by Chris Coyier
  • Demystifying Public Speaking by Lara Hogan
  • Working The Command Line by Remy Sharp


  • The Revenant by Michael Punke
  • The Adjacent by Christopher Priest
  • Helliconia Spring by Brian Aldiss
  • High Rise by J.G. Ballard
  • The Affirmation by Christopher Priest
  • Brodeck’s Report by Philippe Claudel
  • Greybeard by Brian Aldiss
  • Fictions by Jorge Luis Borges
  • The Long Way to a Small Angry Planet by Becky Chambers
  • The Dark Forest by Cixin Liu
  • Death’s End by Cixin Liu
  • The First Fifteen Lives of Harry August by Claire North

Seems kinda meagre to me. Either I need to read more books or I need to keep better track of what books I’m reading when. Starting now.

Twenty sixteen

Sun, 01 Jan 2017 14:51:14 GMT

When I took a look at back at 2015, it was to remark on how nicely uneventful it was. I wish I could say the same about 2016. Instead, this was the year that too damned much kept happening. The big picture was dominated by Brexit and Trump, disasters that are sure to shape events for years to come. I try to keep the even bigger picture in perspective and remind myself that our species is doing well, and that we’re successfully battling poverty, illiteracy, violence, pollution, and disease. But it’s so hard sometimes. I still think the overall trend for this decade will be two steps forward, but the closing half is almost certain to be one step back. Some people close to me have had a really shitty year. More than anything, I wish I could do more to help them. Right now I’m thinking that one of the best things I could wish for 2017 is for it to be an uneventful year. I’d really like it if the end-of-year round-up in 365 days time had no world-changing events. But for me personally? 2016 was fine. I didn’t accomplish any big goals—although I’m very proud to have published Resilient Web Design—but I’ve had fun at work, and as always, I’m very grateful for all the opportunities that came my way. I ate some delicious food… I went to beautiful places… And I got to hang out with some lovely doggies… Have a happy—and uneventful—new year! [...]

The many formats of Resilient Web Design

Wed, 28 Dec 2016 21:57:10 GMT

If you don’t like reading in a web browser, you might like to know that Resilient Web Design is now available in more formats.

Jiminy Panoz created a lovely EPUB version. I tried it out in Apple’s iBooks app and it looks great. I tried to submit it to the iBooks store too, but that process threw up a few too many roadblocks.

Oliver Williams has created a MOBI version. That’s means you can read it on a Kindle. I plugged my old Kindle into my computer, dragged that file onto its disc image, and it worked a treat.

And there’s always the PDF versions; one in portrait and another in landscape format. Those were generated straight from the print styles.

Oh, and there’s the podcast. I’ve only released two chapters so far. The Christmas break and an untimely cold have slowed down the release schedule a little bit.

I’d love to make a physical, print-on-demand version of Resilient Web Design available—maybe through Lulu—but my InDesign skills are non-existent.

If you think the book should be available in any other formats, and you fancy having a crack at it, please feel free to use the source files.

Deep linking with fragmentions

Mon, 19 Dec 2016 12:57:36 GMT

When I was marking up Resilient Web Design I wanted to make sure that people could link to individual sections within a chapter. So I added IDs to all the headings. There’s no UI to expose that though—like the hover pattern that some sites use to show that something is linkable—so unless you know the IDs are there, there’s no way of getting at them other than “view source.”

But if you’re reading a passage in Resilient Web Design and you highlight some text, you’ll notice that the URL updates to include that text after a hash symbol. If that updated URL gets shared, then anyone following it should be sent straight to that string of text within the page. That’s fragmentions in action:

Fragmentions find the first matching word or phrase in a document and focus its closest surrounding element. The match is determined by the case-sensitive string following the # (or ## double-hash)

It’s a similar idea to Eric and Simon’s proposal to use CSS selectors as fragment identifiers, but using plain text instead. You can find out more about the genesis of fragmentions from Kevin. I’m using Jonathon Neal’s script with some handy updates from Matthew.

I’m using the fragmention support to power the index of the book. It relies on JavaScript to work though, so Matthew has come to the rescue again and created a version of the site with IDs for each item linked from the index (I must get around to merging that).

The fragmention functionality is ticking along nicely with one problem…

I’ve tweaked the typography of Resilient Web Design to within an inch of its life, including a crude but effective technique to avoid widowed words at the end of a paragraph. The last two words of every paragraph are separated by a UTF-8 no-break space character instead of a regular space.

That solves the widowed words problem, but it confuses the fragmention script. Any selected text that includes the last two words of a paragraph fails to match. I’ve tried tweaking the script, but I’m stumped. If you fancy having a go, please have at it.

Update: And fixed! Thanks to Lee.

Print styles

Fri, 16 Dec 2016 16:53:13 GMT

I really wanted to make sure that the print styles for Resilient Web Design were pretty good—or at least as good as they could be given the everlasting lack of support for many print properties in browsers.

Here’s the first thing I added:

@media print {
  @page {
    margin: 1in 0.5in 0.5in;
    orphans: 4;
    widows: 3;

That sets the margins of printed pages in inches (I could’ve used centimetres but the numbers were nice and round in inches). The orphans: 4 declaration says that if there’s less than 4 lines on a page, shunt the text onto the next page. And widows: 3 declares that there shouldn’t be less than 3 lines left alone on a page (instead more lines will be carried over from the previous page).

I always get widows and orphans confused so I remind myself that orphans are left alone at the start; widows are left alone at the end.

I try to make sure that some elements don’t get their content split up over page breaks:

@media print {
  p, li, pre, figure, blockquote {
    page-break-inside: avoid;

I don’t want headings appearing at the end of a page with no content after them:

@media print {
  h1,h2,h3,h4,h5 {
    page-break-after: avoid;

But sections should always start with a fresh page:

@media print {
  section {
    page-break-before: always;

There are a few other little tweaks to hide some content from printing, but that’s pretty much it. Using print preview in browsers showed some pretty decent formatting. In fact, I used the “Save as PDF” option to create the PDF versions of the book. The portrait version comes from Chrome’s preview. The landscape version comes from Firefox, which offers more options under “Layout”.

For some more print style suggestions, have a look at the article I totally forgot about print style sheets. There’s also tips and tricks for print style sheets on Smashing Magazine. That includes a clever little trick for generating QR codes that only appear when a document is printed. I’ve used that technique for some page types over on The Session.