Journal tags: ba



Coaching on the Clearleft podcast

Season three of the Clearleft podcast is here!

The first episode is a nice gentle one to ease into things. It’s about coaching …and training …and mentorship. Basically I wanted to find out what the differences are between those three things.

But I must confess, there’s a commercial reason why this episode is coming out now. There’s a somewhat salesy promotion of an upcoming coaching programme with Julia Whitney. This is definitely the most overt marketing I’ve done on the Clearleft podcast, but if you listen to the episode, I think you’ll agree that it fits well with the theme.

Fear not, future episodes will not feature this level of cross-promotion. Far from it. You can expect some very revealing podcast episodes that pull no punches in getting under the skin of design at Clearleft.

The stars of this episode are my colleagues Rebecca and Chris, who were an absolute joy to interview.

Have a listen and hear for yourself.

Upgrade paths

After I jotted down some quick thoughts last week on the disastrous way that Google Chrome rolled out a breaking change, others have posted more measured and incisive takes:

In fairness to Google, the Chrome team is receiving the brunt of the criticism because they were the first movers. Mozilla and Apple are on baord with making the same breaking change, but Google is taking the lead on this.

As I said in my piece, my issue was less to do with whether confirm(), prompt(), and alert() should be deprecated but more to do with how it was done, and the woeful lack of communication.

Thinking about it some more, I realised that what bothered me was the lack of an upgrade path. Considering that dialog is nowhere near ready for use, it seems awfully cart-before-horse-putting to first remove a feature and then figure out a replacement.

I was chatting to Amber recently and realised that there was a very different example of a feature being deprecated in web browsers…

We were talking about the KeyboardEvent.keycode property. Did you get the memo that it’s deprecated?

But fear not! You can use the KeyboardEvent.code property instead. It’s much nicer to use too. You don’t need to look up a table of numbers to figure out how to refer to a specific key on the keyboard—you use its actual value instead.

So the way that change was communicated was:

Hey, you really shouldn’t use the keycode property. Here’s a better alternative.

But with the more recently change, the communication was more like:

Hey, you really shouldn’t use confirm(), prompt(), or alert(). So go fuck yourself.


There was quite a kerfuffle recently about a feature being removed from Google Chrome. To be honest, the details don’t really matter for the point I want to make, but for the record, this was about removing alert and confirm dialogs from cross-origin iframes (and eventually everywhere else too).

It’s always tricky to remove a long-established feature from web browsers, but in this case there were significant security and performance reasons. The problem was how the change was communicated. It kind of wasn’t. So the first that people found out about it about was when things suddenly stopped working (like CodePen embeds).

The Chrome team responded quickly and the change has now been pushed back to next year. Hopefully there will be significant communication before that to let site owners know about the upcoming breakage.

So all’s well that ends well and we’ve all learned a valuable lesson about the importance of communication.

Or have we?

While this was going on, Emily Stark tweeted a more general point about breakage on the web:

Breaking changes happen often on the web, and as a developer it’s good practice to test against early release channels of major browsers to learn about any compatibility issues upfront.

Yikes! To me, this appears wrong on almost every level.

First of all, breaking changes don’t happen often on the web. They are—and should be—rare. If that were to change, the web would suffer massively in terms of predictability.

Secondly, the onus is not on web developers to keep track of older features in danger of being deprecated. That’s on the browser makers. I sincerely hope we’re not expected to consult a site called

I wasn’t the only one surprised by this message.

Simon says:

No, no, no, no! One of the best things about developing for the web is that, as a rule, browsers don’t break old code. Expecting every website and application to have an active team of developers maintaining it at all times is not how the web should work!

Edward Faulkner:

Most organizations and individuals do not have the resources to properly test and debug their website against Chrome canary every six weeks. Anybody who published a spec-compliant website should be able to trust that it will keep working.

Evan You:

This statement seriously undermines my trust in Google as steward for the web platform. When did we go from “never break the web” to “yes we will break the web often and you should be prepared for it”?!

It’s worth pointing out that the original tweet was not an official Google announcement. As Emily says right there on her Twitter account:

Opinions are my own.

Still, I was shaken to see such a cavalier attitude towards breaking changes on the World Wide Web. I know that removing dangerous old features is inevitable, but it should also be exceptional. It should not be taken lightly, and it should certainly not be expected to be an everyday part of web development.

It’s almost miraculous that I can visit the first web page ever published in a modern web browser and it still works. Let’s not become desensitised to how magical that is. I know it’s hard work to push the web forward, constantly add new features, while also maintaining backward compatibility, but it sure is worth it! We have collectively banked three decades worth of trust in the web as a stable place to build a home. Let’s not blow it.

If you published a website ten or twenty years ago, and you didn’t use any proprietary technology but only stuck to web standards, you should rightly expect that site to still work today …and still work ten and twenty years from now.

There was something else that bothered me about that tweet and it’s not something that I saw mentioned in the responses. There was an unspoken assumption that the web is built by professional web developers. That gave me a cold chill.

The web has made great strides in providing more and more powerful features that can be wielded in learnable, declarative, forgiving languages like HTML and CSS. With a bit of learning, anyone can make web pages complete with form validation, lazily-loaded responsive images, and beautiful grids that kick in on larger screens. The barrier to entry for all of those features has lowered over time—they used to require JavaScript or complex hacks. And with free(!) services like Netlify, you could literally drag a folder of web pages from your computer into a browser window and boom!, you’ve published to the entire world.

But the common narrative in the web development community—and amongst browser makers too apparently—is that web development has become more complex; so complex, in fact, that only an elite priesthood are capable of making websites today.

Absolute bollocks.

You can choose to make it really complicated. Convince yourself that “the modern web” is inherently complex and convoluted. But then look at what makes it complex and convoluted: toolchains, build tools, pipelines, frameworks, libraries, and abstractions. Please try to remember that none of those things are required to make a website.

This is for everyone. Not just for everyone to consume, but for everyone to make.

A Few Notes on A Few Notes on The Culture

When I post a link, I do it for two reasons.

First of all, it’s me pointing at something and saying “Check this out!”

Secondly, it’s a way for me to stash something away that I might want to return to. I tag all my links so when I need to find one again, I just need to think “Now what would past me have tagged it with?” Then I type the appropriate URL:

There are some links that I return to again and again.

Back in 2008, I linked to a document called A Few Notes on The Culture. It’s a copy of a post by Iain M Banks to a newsgroup back in 1994.

Alas, that link is dead. Linkrot, innit?

But in 2013 I linked to the same document on a different domain. That link still works even though I believe it was first published around twenty(!) years ago (view source for some pre-CSS markup nostalgia).

Anyway, A Few Notes On The Culture is a fascinating look at the world-building of Iain M Banks’s Culture novels. He talks about the in-world engineering, education, biology, and belief system of his imagined utopia. The part that sticks in my mind is when he talks about economics:

Let me state here a personal conviction that appears, right now, to be profoundly unfashionable; which is that a planned economy can be more productive - and more morally desirable - than one left to market forces.

The market is a good example of evolution in action; the try-everything-and-see-what-works approach. This might provide a perfectly morally satisfactory resource-management system so long as there was absolutely no question of any sentient creature ever being treated purely as one of those resources. The market, for all its (profoundly inelegant) complexities, remains a crude and essentially blind system, and is — without the sort of drastic amendments liable to cripple the economic efficacy which is its greatest claimed asset — intrinsically incapable of distinguishing between simple non-use of matter resulting from processal superfluity and the acute, prolonged and wide-spread suffering of conscious beings.

It is, arguably, in the elevation of this profoundly mechanistic (and in that sense perversely innocent) system to a position above all other moral, philosophical and political values and considerations that humankind displays most convincingly both its present intellectual immaturity and — through grossly pursued selfishness rather than the applied hatred of others — a kind of synthetic evil.

Those three paragraphs might be the most succinct critique of unfettered capitalism I’ve come across. The invisible hand as a paperclip maximiser.

Like I said, it’s a fascinating document. In fact I realised that I should probably store a copy of it for myself.

I have a section of my site called “extras” where I dump miscellaneous stuff. Most of it is unlinked. It’s mostly for my own benefit. That’s where I’ve put my copy of A Few Notes On The Culture.

Here’s a funny thing …for all the times that I’ve revisited the link, I never knew anything about the site is was hosted on——so this most recent time, I did a bit of clicking around. Clearly it’s the personal website of a sci-fi-loving college student from the early 2000s. But what came as a revelation to me was that the site belonged to …Adrian Hon!

I’m impressed that he kept his old website up even after moving over to the domain, founding Six To Start, and writing A History Of The Future In 100 Objects. That’s a great snackable book, by the way. Well worth a read.

Safari 15

If you download Safari Technology Preview you can test drive features that are on their way in Safari 15. One of those features, announced at Apple’s World Wide Developer Conference, is coloured browser chrome via support for the meta value of “theme-color.” Chrome on Android has supported this for a while but I believe Safari is the first desktop browser to add support. They’ve also added support for the media attribute on that meta element to handle “prefers-color-scheme.”

This is all very welcome, although it does remind me a bit of when Internet Explorer came out with the ability to make coloured scrollbars. I mean, they’re nice features’n’all, but maybe not the most pressing? Safari is still refusing to acknowledge progressive web apps.

That’s not quite true. In her WWDC video Jen demonstrates how you can add a progressive web app like Resilient Web Design to your home screen. I’m chuffed that my little web book made an appearance, but when you see how you add a site to your home screen in iOS, it’s somewhat depressing.

The steps to add a website to your home screen are:

  1. Tap the “share” icon. It’s not labelled “share.” It’s a square with an arrow coming out of the top of it.
  2. A drawer pops up. The option to “add to home screen” is nowhere to be seen. You have to pull the drawer up further to see the hidden options.
  3. Now you must find “add to home screen” in the list
  • Copy
  • Add to Reading List
  • Add Bookmark
  • Add to Favourites
  • Find on Page
  • Add to Home Screen
  • Markup
  • Print

It reminds of this exchange in The Hitchhiker’s Guide To The Galaxy:

“You hadn’t exactly gone out of your way to call attention to them had you? I mean like actually telling anyone or anything.”

“But the plans were on display…”

“On display? I eventually had to go down to the cellar to find them.”

“That’s the display department.”

“With a torch.”

“Ah, well the lights had probably gone.”

“So had the stairs.”

“But look you found the notice didn’t you?”

“Yes,” said Arthur, “yes I did. It was on display in the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying ‘Beware of The Leopard.’”

Safari’s current “support” for adding progressive web apps to the home screen feels like the minimum possible …just enough to use it as a legal argument if you happen to be litigated against for having a monopoly on app distribution. “Hey, you can always make a web app!” It’s true in theory. In practice it’s …suboptimal, to put it mildly.

Still, those coloured tab bars are very nice.

It’s a little bit weird that this stylistic information is handled by HTML rather than CSS. It’s similar to the meta viewport value in that sense. I always that the plan was to migrate that to CSS at some point, but here we are a decade later and it’s still very much part of our boilerplate markup.

Some people have remarked that the coloured browser chrome can make the URL bar look like part of the site so people might expect it to operate like a site-specific search.

I also wonder if it might blur “the line of death”; that point in the UI where the browser chrome ends and the website begins. Does the unified colour make it easier to spoof browser UI?

Probably not. You can already kind of spoof browser UI by using the right shade of grey. Although the removal any kind of actual line in Safari does give me pause for thought.

I tend not to think of security implications like this by default. My first thought tends to be more about how I can use the feature. It’s only after a while that I think about how bad actors might abuse the same feature. I should probably try to narrow the gap between those thoughts.

Broad Band

I like to alternate between reading fiction and non-fiction. The fiction is often of the science variety. Actually, so is the non-fiction.

There was a non-fiction book I had queued up for a while and I finally got around to reading. Broad Band by Claire L. Evans. Now I’m kicking myself that I didn’t read it earlier. I think I might’ve been remembering how I found Mar Hicks’s Programmed Inequality to be a bit of a slog—a fascinating topic, but written in a fairly academic style. Broad Band covers some similar ground, but wow, is the writing style in a class of its own!

This book is pretty much the perfect mix. The topic is completely compelling—a history of women in computing. The stories are rivetting—even when I thought I knew the history, this showed me how little I knew. And the voice of the book is pure poetry.

It’s not often that I read a book that I recommend wholeheartedly to everyone. I prefer to tailor my recommendations to individual situations. But in the case of Broad Band, I honesty think that anyone would enjoy it.

I absolutely loved it. So did Cory Doctorow:

Because she is a brilliant and lyrical writer she brings these women to life, turns them into fully formed characters, makes you see and feel their life stories, frustrations and triumphs.

Even the most celebrated women of tech history – Ada Lovelace, Grace Hopper – leap off the page as people, not merely historical personages or pioneers. Again, these are stories I thought I knew, and realized I didn’t.

Yes! That!

Read it for yourself and see what you think.

Principles and the English language

I work with words. Sometimes they’re my words. Sometimes they’re words that my colleagues have written:

One of my roles at Clearleft is “content buddy.” If anyone is writing a talk, or a blog post, or a proposal and they want an extra pair of eyes on it, I’m there to help.

I also work with web technologies, usually front-of-the-front-end stuff. HTML, CSS, and JavaScript. The technologies that users experience directly in web browsers.

I think a lot about design principles for the web. The two principles I keep coming back to are the robustness principle and the principle of least power.

When it comes to words, the guide that I return to again and again is George Orwell, specifically his short essay, Politics and the English Language.

Towards the end, he offers some rules for writing.

  1. Never use a metaphor, simile, or other figure of speech which you are used to seeing in print.
  2. Never use a long word where a short one will do.
  3. If it is possible to cut a word out, always cut it out.
  4. Never use the passive where you can use the active.
  5. Never use a foreign phrase, a scientific word, or a jargon word if you can think of an everyday English equivalent.
  6. Break any of these rules sooner than say anything outright barbarous.

These look a lot like design principles. Not only that, but some of them look like specific design principles. Take the robustness principle:

Be conservative in what you send, be liberal in what you accept.

That first part applies to Orwell’s third rule:

If it is possible to cut a word out, always cut it out.

Be conservative in what words you send.

Then there’s the principle of least power:

Choose the least powerful language suitable for a given purpose.

Compare that to Orwell’s second rule:

Never use a long word where a short one will do.

That could be rephrased as:

Choose the shortest word suitable for a given purpose.

Or, going in the other direction, the principle of least power could be rephrased in Orwell’s terms as:

Never use a powerful language where a simple language will do.

Oh, I like that! I like that a lot.

Season two of the Clearleft podcast

Season two of the Clearleft podcast is in the can. Taking a step back and looking at the six episodes, I think it turned out very well indeed.

Episode One

Design Leadership. Lots of smart people in this one. And I like that the source material is a real mix: conference talks, a roundtable discussion, and an interview.

Episode Two

Employee Experience Design. More of a deep dive than a broad overview. It’s pretty much a two-hander from Chris and Katie.

Episode Three

Accessibility. This one got a lot of attention, and rightly so in my opinion. It’s got three excellent contributors: Laura, Léonie, and Cassie. My job was to get out of the way and string their knowledge bombs together.

Episode Four

Prototyping. I had three good stories to work with from Benjamin, Lorenzo, and Trys. Then at the last minute I was able to add an interview with Adekunle which ties the whole thing up nicely.

Episode Five

Diversity and Inclusion. I think this might be the highlight of the season. Again, it’s got a mix of source material from conference talks and interviews. The quality of the contributions is exceptionally good. Once again, I found my job was to mostly get out of the way and line things up so they flowed well.

Episode Six

Remote Work. I wish I could see that it was my perfect planning that led to this episode being released exactly one year on from the start of lockdown. But really it was just a very fortunate coincidence. It did give this episode some extra resonance though. And I like that the final episode of the season has the widest range of contributors. It’s like the whole cast came back for the season finale.

I also wrote a bit about what I did behind the scenes for each episode of this season:

  1. Design Leadership
  2. Employee Experience Design
  3. Accessibility
  4. Prototyping
  5. Diversity and Inclusion
  6. Remote Work

My sincerest thanks to everyone who contributed to this season of the Clearleft podcast, especially everyone outside Clearleft who kindly agreed to be interviewed: Temi, Laura, Léonie, Adekunle, Rifa, and Elaine.

The Clearleft podcast will take a little break now and so will I. But I’m already thinking about topics for the next season. I feel like I’m starting to get a feel for what’s working so you can another six-episode season down the line.

To make sure you don’t miss the next season, I recommend subscribing to the RSS feed, or you can subscribe on Apple, Spotify, Google, and anywhere else that dispenses podcasts.

Remote work on the Clearleft podcast

The sixth episode of season two of the Clearleft podcast is available now. The last episode of the season!

The topic is remote work. The timing is kind of perfect. It was exactly one year ago today that Clearleft went fully remote. Having a podcast episode to mark the anniversary seems fitting.

I didn’t interview anyone specifically for this episode. Instead, whenever I was chatting to someone about some other topic—design systems, prototyping, or whatever—I’d wrap up by asking them to describe their surroundings and ask them how they were adjusting to life at home. After two season’s worth of interviews, I had a decent library of responses. So this episode includes voices you last heard from back in season one: Paul, Charlotte, Amy, and Aarron.

Then the episode shifts. I’ve got excerpts from a panel discussion we held a while back on the future of work. These panel discussions used to happen up in London, but this one was, obviously, online. It’s got a terrific line-up: Jean, Holly, Emma, and Lola, all dialing in from different countries and all sharing their stories openly and honestly. (Fun fact: I first met Lola three years ago at the Pixel Up conference in South Africa and on this day in 2018 we were out on Safari together.)

I’m happy with how this episode turned out. It’s a fitting finish to the season. It’s just seventeen and a half minutes long so take a little time out of your day to have a listen.

As always, if you like what you hear, please spread the word.

Employee experience design on the Clearleft podcast

The second episode of the second season of the Clearleft podcast is out. It’s all about employee experience design.

This topic came out of conversations with Katie. She really enjoys getting stuck into to the design challenges of the “backstage” tools that are often neglected. This is an area that Chris has been working in recently too, so I quized him on this topic.

They’re both super smart people which makes for a thoroughly enjoyable podcast episode. I usually have more guests on a single episode but it was fun to do a two-hander for once.

The whole thing comes in at just under seventeen minutes and there are some great stories and ideas in there. Have a listen.

And if you’re enjoying listening to the Clearleft podcast as much as I’m enjoying making it, be sure to spread the word wherever you share your recommnedations: Twitter, LinkedIn, Slack, your own website, the rooftop.

Web Audio API weirdness on iOS

I told you about how I’m using the Web Audio API on The Session to generate synthesised audio of each tune setting. I also said:

Except for some weirdness on iOS that I had to fix.

Here’s that weirdness…

Let me start by saying that this isn’t anything to do with requiring a user interaction (the Web Audio API insists on some kind of user interaction to prevent developers from having auto-playing sound on websites). All of my code related to the Web Audio API is inside a click event handler. This is a different kind of weirdness.

First of all, I noticed that if you pressed play on the audio player when your iOS device is on mute, then you don’t hear any audio. Seems logical, right? Except if using the same device, still set to mute, you press play on a video or audio element, the sound plays just fine. You can confirm this by going to Huffduffer and pressing play on any of the audio elements there, even when your iOS device is set on mute.

So it seems that iOS has different criteria for the Web Audio API than it does for audio or video. Except it isn’t quite that straightforward.

On some pages of The Session, as well as the audio player for tunes (using the Web Audio API) there are also embedded YouTube videos (using the video element). Press play on the audio player; no sound. Press play on the YouTube video; you get sound. Now go back to the audio player and suddenly you do get sound!

It’s almost like playing a video or audio element “kicks” the browser into realising it should be playing the sound from the Web Audio API too.

This was happening on iOS devices set to mute, but I was also getting reports of it happening on devices with the sound on. But it’s that annoyingly intermittent kind of bug that’s really hard to reproduce consistently. Sometimes the sound doesn’t play. Sometimes it does.

Following my theory that the browser needs a “kick” to get into the right frame of mind for the Web Audio API, I resorted to a messy little hack.

In the event handler for the audio player, I generate the “kick” by playing a second of silence using the JavaScript equivalent of the audio element:

var audio = new Audio('1-second-of-silence.mp3');;

I’m not proud of that. It’s so hacky that I’ve even wrapped the code in some user-agent sniffing on the server, and I never do user-agent sniffing!

Still, if you ever find yourself getting weird but inconsistent behaviour on iOS using the Web Audio API, this nasty little hack could help.


I spent the last couple of weekends rolling out a new feature on The Session. It involves playing audio in a web page. No big deal these days, right? But the history involves some old file formats…

The first venerable format is ABC notation. File extension: .abc, mime type: text/ It’s an ingenious text format for musical notation using ASCII. The metadata of the piece of music is defined in JSON-like key/value pairs. Then the contents are encoded with letters: A, B, C, etc. Uppercase and lowercase denote different octaves. Numbers can be used for note lengths.

The format was created by Chris Walshaw in 1997 when dial-up was the norm. With ABC, people were able to swap tunes on email lists or bulletin boards without transferring weighty image or sound files. If you had ABC software on your computer, you could convert that lightweight text file into sheet music …or audio.

That brings me to the second old format: midi files. File extension: .mid, mime-type: audio/midi. Like ABC, it’s a lightweight format for encoding the instructions for music instead of the music itself.

Think of it like SVG: instead of storing the final pixels of an image, SVG stores the instructions for drawing the image instead. The instructions in a midi file are like “play this note for this long on this instrument.” Again, as with ABC, you need some software to turn the instructions into sound.

There was a time when lots of software could play midi files. Quicktime on the Mac, for example. You could even embed midi files in web pages. I mean literally embed them …with the embed element. No Geocities page was complete without an autoplaying midi file.

On The Session, people submit tunes in ABC format. Then, using the amazing ABCJS JavaScript library, the ABC is turned into SVG on the fly! For years I’ve also offered midi files, generated on the server from the ABC notation.

But times have changed. These days it’s hard to find software that plays midi files. Quicktime doesn’t do it anymore. And you’d need to go to the app store on iOS to find a midi file player. It’s time to phase out the midi files on The Session.

I still want to provide automatically-generated audio though. Fortunately ABCJS gives me a way to do this. But instead of using the old technology of midi files, it uses a more modern browser feature: the Web Audio API.

The end result sounds like a midi file, but the underlying technique is more like a synthesiser. There’s a separate mp3 file for each note. The JavaScript figures out how long each “sample” needs to be played for, strings them all together, and outputs them with Web Audio. So you’ve got cutting-edge browser technology recreating a much older file format. Paul Rosen—the creator of ABCJS—has a presentation explaining how it all works under the hood.

Not only is there a separate short mp3 file for each note in seven octaves, but if you want the sound of a different instrument, you need samples for all seven octaves in that instrument. They’re called soundfonts.

Paul provides soundfonts for ABCJS. It’s a repo that was forked from this repo from Benjamin Gleitzman. And here’s where it gets small worldy…

The reason why Benjamin has a repo of soundfonts is because he needed to create midi-like audio in the browser. He wanted to do this for a project on September 28th and 29th, 2013 …at Science Hack Day San Francisco!

I was there too—working on my own audio-related hack—and I remember the excellent (and winning) hack that Benjamin worked on. It was called Symphony of Satellites and it’s still online along with the promo video. Here’s Benjamin’s post-hackday write-up from seven years ago.

It’s rare that the worlds of the web and Irish music cross over. When I got to meet Paul—creator of ABCJS—at a web conference a couple of years ago it kind of blew my mind. Last weekend when I set out to dabble with a feature on The Session, I certainly didn’t expect to stumble on a connection to Science Hack Day! (Aside: the first Science Hack Day was ten years ago—yowzers!)

Anyway, I was able to get that audio playback working on The Session. Except for some weirdness on iOS that I had to fix. But that’s a hack for another day.

Unobtrusive feedback

Ten years ago I gave a talk at An Event Apart all about interaction design. It was called Paranormal Interactivity. You can watch the video, listen to the audio or read the transcript if you like.

I think it holds up pretty well. There’s one interaction pattern in particular that I think has stood the test of time. In the talk, I introduce this pattern as something you can see in action on Huffduffer:

I was thinking about how to tell the user that something’s happened without distracting them from their task, and I thought beyond the web. I thought about places that provide feedback mechanisms on screens, and I thought of video games.

So we all know Super Mario, right? And if you think about when you’re collecting coins in Super Mario, it doesn’t stop the game and pop up an alert dialogue and say, “You have just collected ten points, OK, Cancel”, right? It just does it. It does it in the background, but it does provide you with a feedback mechanism.

The feedback you get in Super Mario is about the number of points you’ve just gained. When you collect an item that gives you more points, the number of points you’ve gained appears where the item was …and then drifts upwards as it disappears. It’s unobtrusive enough that it won’t distract you from the gameplay you’re concentrating on but it gives you the reassurance that, yes, you have just gained points.

I think this a neat little feedback mechanism that we can borrow for subtle Ajax interactions on the web. These are actions that don’t change much of the content. The user needs to be able to potentially do lots of these actions on a single page without waiting for feedback every time.

On Huffduffer, for example, you might be looking at a listing of people that you can choose to follow or unfollow. The mechanism for doing that is a button per person. You might potentially be clicking lots of those buttons in quick succession. You want to know that each action has taken effect but you don’t want to be interrupted from your following/unfollowing spree.

You get some feedback in any case: the button changes. Maybe the text updates from “follow” to “unfollow” accompanied by a change in colour (this is what you’ll see on Twitter). The Super Mario style feedback is in addition to that, rather than instead of.

I’ve made a Codepen so you can see a reduced test case of the Super Mario feedback in action.

See the Pen Unobtrusive feedback by Jeremy Keith (@adactio) on CodePen.

Here’s the code available as a gist.

It’s a function that takes two arguments: the element that the feedback originates from (pass in a DOM node reference for this), and the contents of the feedback (this can be a string of text or it can be HTML …or SVG). When you call the function with those two arguments, this is what happens:

  1. The JavaScript generates a span element and puts the feedback contents inside it.
  2. Then it positions that element right over the element that the feedback originates from.
  3. Then there’s a CSS transform. The feedback gets a translateY applied so it drifts upward. At the same time it gets its opacity reduced from 1 to 0 so it’s fading away.
  4. Finally there’s a transitionend event that fires when the animation is over. Once that event fires, the generated span is destroyed.

When I first used this pattern on Huffduffer, I’m pretty sure I was using jQuery. A few years later I rewrote it in vanilla JavaScript. That was four years ago so I wonder if the code could be improved. Have a go if you fancy it.

Still, even if the code could benefit from an update, I’m pleased that the underlying pattern still holds true. I used it recently on The Session and it’s working a treat for a new Ajax interaction there (bookmarking or unbookbarking an item).

If you end up using this unobtrusive feedback pattern anyway, please let me know—I’d love to see more examples of it in the wild.

Netlify redirects and downloads

Making the Clearleft podcast is a lot of fun. Making the website for the Clearleft podcast was also fun.

Design wise, it’s a riff on the main Clearleft site in terms of typography and general layout. On the development side, it was an opportunity to try out an exciting tech stack. The workflow goes something like this:

  • Open a text editor and type out HTML and CSS.

Comparing this to other workflows I’ve used in the past, this is definitely the most productive way of working. Some stats:

  • Time spent setting up build tools: 00:00
  • Time spent wrangling the pipeline to do exactly what you want: 00:00
  • Time spent trying to get the damn build tools to work again when you return to the project after leaving it alone for more than a few months: 00:00:00

I have some files. Some images, three font files, a few pages of HTML, one RSS feed, one style sheet, and one minimal service worker script. I don’t need a web server to do anything more than serve up those files. No need for any dynamic server-side processing.

I guess this is JAMstack. Though, given that the J stands for JavaScript, the A stands for APIs, and I’m not using either, technically it’s Mstack.

Netlify suits my hosting needs nicely. It also provides the added benefit that, should I need to update my CSS, I don’t need to add a query string or anything to the link elements in the HTML that point to the style sheet: Netlify does cache invalidation for you!

The mp3 files of the actual podcast episodes are stored on S3. I link to those mp3 files from enclosure elements in the RSS feed, which is what makes it a podcast. I also point to the mp3 files from audio elements on the individual episode pages—just above the transcript of each episode. Here’s the page for the most recent episode.

I also want people to be able to download the mp3 file directly if they want (or if they want to huffduff an episode). So I provide a link to the mp3 file with a good ol’-fashioned a element with an href attribute.

I throw in one more attribute on that link. The download attribute tells the browser that the URL in the href attribute should be downloaded instead of visited. If you give a value for the download attribute, it will over-ride the file name:

<a href="/files/" download="">download</a>

Or you can use it as a Boolean attribute without any value if you’re happy with the file name:

<a href="/files/" download>download</a>

There’s one catch though. The download attribute only works for files on the same origin. That’s an issue for me. My site is but my audio files are hosted on—the download attribute will be ignored and the mp3 files will play in the browser instead of downloading.

Trys pointed me to the solution. It turns out that Netlify can do some server-side processing. It can do redirects.

I added a file called _redirects to the root of my project. It contains one line:

/download/*  200

That says that any URLs beginning with /download/ should redirect to Everything after the closing slash is captured with that wild card asterisk. That’s then passed along to the redirect URL as :splat. That’s a new one on me. I hadn’t come across that terminology, but as someone who can never remember the syntax of regular expressions, it works for me.

Oh, and the 200at the end is the status code: okay.

Now I can use this /download/ path in my link:

<a href="/download/season01episode06.mp3" download>Download mp3</a>

Because this URL on the same origin, the download attribute works just fine.


Back in February, I wrote about an excellent proposal by Jake for how browsers could display URLs in a safer way. Crucially, this involved highlighting the important part of the URL, but didn’t involve hiding any part. It’s a really elegant solution.

Turns out it was a Trojan horse. Chrome are now running an experiment where they will do the exact opposite: they will hide parts of the URL instead of highlighting the important part.

You can change this behaviour if you’re in the less than 1% of people who ever change default settings in browsers.

I’m really disappointed to see that Jake’s proposal isn’t going to be implemented. It was a much, much better solution.

No doubt I will hear rejoinders that the “solution” that Chrome is experimenting with is pretty similar to what Jake proposed. Nothing could be further from the truth. Jake’s solution empowered users with knowledge without taking anything away. What Chrome will be doing is the opposite of that, infantalising users and making decisions for them “for their own good.”

Seeing a complete URL is going to become a power-user feature, like View Source or user style sheets.

I’m really sad about that because, as Jake’s proposal demonstrates, it doesn’t have to be that way.

CSS custom properties and the cascade

When I wrote about programming CSS to perform Sass colour functions I said this about the brilliant Lea Verou:

As so often happens when I’m reading something written by Lea—or seeing her give a talk—light bulbs started popping over my head (my usual response to Lea’s knowledge bombs is either “I didn’t know you could do that!” or “I never thought of doing that!”).

Well, it happened again. This time I was reading her post about hybrid positioning with CSS variables and max() . But the main topic of the post wasn’t the part that made go “Huh! I never knew that!”. Towards the end of her article she explained something about the way that browsers evaluate CSS custom properties:

The browser doesn’t know if your property value is valid until the variable is resolved, and by then it has already processed the cascade and has thrown away any potential fallbacks.

I’m used to being able to rely on the cascade. Let’s say I’m going to set a background colour on paragraphs:

p {
  background-color: red;
  background-color: color(display-p3 1 0 0);

First I’ve set a background colour using a good ol’ fashioned keyword, supported in browsers since day one. Then I declare the background colour using the new-fangled color() function which is supported in very few browsers. That’s okay though. I can confidently rely on the cascade to fall back to the earlier declaration. Paragraphs will still have a red background colour.

But if I store the background colour in a custom property, I can no longer rely on the cascade.

:root {
  --myvariable: color(display-p3 1 0 0);
p {
  background-color: red;
  background-color: var(--myvariable);

All I’ve done is swapped out the hard-coded color() value for a custom property but now the browser behaves differently. Instead of getting a red background colour, I get the browser default value. As Lea explains:

…it will make the property invalid at computed value time.

The spec says:

When this happens, the computed value of the property is either the property’s inherited value or its initial value depending on whether the property is inherited or not, respectively, as if the property’s value had been specified as the unset keyword.

So if a browser doesn’t understand the color() function, it’s as if I’ve said:

background-color: unset;

This took me by surprise. I’m so used to being able to rely on the cascade in CSS—it’s one of the most powerful and most useful features in this programming language. Could it be, I wondered, that the powers-that-be have violated the principle of least surprise in specifying this behaviour?

But a note in the spec explains further:

Note: The invalid at computed-value time concept exists because variables can’t “fail early” like other syntax errors can, so by the time the user agent realizes a property value is invalid, it’s already thrown away the other cascaded values.

Ah, right! So first of all browsers figure out the cascade and then they evaluate custom properties. If a custom property evaluates to gobbledygook, it’s too late to figure out what the cascade would’ve fallen back to.

Thinking about it, this makes total sense. Remember that CSS custom properties aren’t like Sass variables. They aren’t evaluated once and then set in stone. They’re more like let than const. They can be updated in real time. You can update them from JavaScript too. It’s entirely possible to update CSS custom properties rapidly in response to events like, say, the user scrolling or moving their mouse. If the browser had to recalculate the cascade every time a custom property didn’t evaluate correctly, I imagine it would be an enormous performance bottleneck.

So even though this behaviour surprised me at first, it makes sense on reflection.

I’ve probably done a terrible job explaining the behaviour here, so I’ve made a Codepen. Although that may also do an equally terrible job.

(Thanks to Amber for talking through this with me and encouraging me to blog about it. And thanks to Lea for expanding my mind. Again.)


Do you have a favourite non-personal photograph?

By non-personal, I mean one that isn’t directly related to your life; photographs of family members, friends, travel (remember travel?).

Even discounting those photographs, there’s still a vast pool of candidates. There are all the amazing pictures taken by photojournalists like Lee Miller. There’s all the awe-inspiring wildlife photography out there. Then there are the kind of posters that end up on bedroom walls, like Robert Doisneau’s The Kiss.

One of my favourite photographs of all time has music as its subject matter. No, not Johnny Cash flipping the bird, although I believe this picture to be just as rock’n’roll.

In the foreground, Séamus Ennis sits with his pipes. In the background, Jean Ritchie is leaning intently over her recording equipment.

This is a photograph of Séamus Ennis and Jean Ritchie. It was probably taken around 1952 or 1953 by Ritchie’s husband, George Pickow, when Jean Ritchie and Alan Lomax were in Ireland to do field recordings.

I love everything about it.

Séamus Ennis looks genuinely larger than life (which, by all accounts, he was). And just look at the length of those fingers! Meanwhile Jean Ritchie is equally indominatable, just as much as part of the story as the musician she’s there to record.

Both of them have expressions that convey how intent they are on their machines—Ennis’s uilleann pipes and Ritchie’s tape recorder. It’s positively steampunk!

What a perfect snapshot of tradition and technology meeting slap bang in the middle of the twentieth century.

Maybe that’s why I love it so much. One single photograph is filled with so much that’s dear to me—traditional Irish music meets long-term archival preservation.

Future Sync 2020

I was supposed to be in Plymouth yesterday, giving the opening talk at this year’s Future Sync conference. Obviously, that train journey never happened, but the conference did.

The organisers gave us speakers the option of pre-recording our talks, which I jumped on. It meant that I wouldn’t be reliant on a good internet connection at the crucial moment. It also meant that I was available to provide additional context—mostly in the form of a deluge of hyperlinks—in the chat window that accompanied the livestream.

The whole thing went very smoothly indeed. Here’s the video of my talk. It was The Layers Of The Web, which I’ve only given once before, at Beyond Tellerrand Berlin last November (in the Before Times).

As well as answering questions in the chat room, people were also asking questions in But rather than answering those questions there, I was supposed to respond in a social medium of my choosing. I chose my own website, with copies syndicated to Twitter.

Here are those questions and answers…

The first few questions were about last years’s CERN project, which opens the talk:

Based on what you now know from the CERN 2019 WorldWideWeb Rebuild project—what would you have done differently if you had been part of the original 1989 Team?

I responded:

Actually, I think the original WWW project got things mostly right. If anything, I’d correct what came later: cookies and JavaScript—those two technologies (which didn’t exist on the web originally) are the source of tracking & surveillance.

The one thing I wish had been done differently is I wish that JavaScript were a same-origin technology from day one:

Next question:

How excited were you when you initially got the call for such an amazing project?

My predictable response:

It was an unbelievable privilege! I was so excited the whole time—I still can hardly believe it really happened!

Later in the presentation, I talked about service workers and progressive web apps. I got a technical question about that:

Is there a limit to the amount of local storage a PWA can use?

I answered:

Great question! Yes, there are limits, but we’re generally talking megabytes here. It varies from browser to browser and depends on the available space on the device.

But files stored using the Cache API are less likely to be deleted than files stored in the browser cache.

More worrying is the announcement from Apple to only store files for a week of browser use:

Finally, there was a question about the over-arching theme of the talk…

Great talk, Jeremy. Do you encounter push-back when using the term “Progressive Enhancement”?

My response:

Yes! …And that’s why I never once used the phrase “progressive enhancement” in my talk. 🙂

There’s a lot of misunderstanding of the term. Rather than correct it, I now avoid it:

Instead of using the phrase “progressive enhancement”, I now talk about the benefits and effects of the technique: resilience, universality, etc.

Future Sync Distributed 2020

A reading of The Enormous Space by J.G. Ballard

Staying at home triggered a memory for me. I remembered reading a short story many years ago. It was by J.G. Ballard, and it described a man who makes the decision not to leave the house.

Being a J.G. Ballard story, it doesn’t end there. Over the course of the story, the house grows and grows in size, forcing the protaganist into ever-smaller refuges within his own home. It really stuck with me.

I tried tracking it down with some Duck Duck Going. Searching for “j.g. ballard weird short story” doesn’t exactly narrow things down, but eventually I spotted the book that I had read the story in. It was called War Fever. I think I read it back when I was living in Germany, so that would’ve been in the ’90s. I certainly don’t have a copy of the book any more.

But I was able to look up a table of contents and find a title for the story that was stuck in my head. It’s called The Enormous Space.

Alas, I couldn’t find any downloadable versions—War Fever doesn’t seem to be available for the Kindle.

Then I remembered the recent announcement from the Internet Archive that it was opening up the National Emergency Library. The usual limits on “checking out” books online are being waived while physical libraries remain closed.

I found The Complete Stories of J.G. Ballard and borrowed it just long enough to re-read The Enormous Space.

If anything, it’s creepier and weirder than I remembered. But it’s laced with more black comedy than I remembered.

I thought you might like to hear this story, so I made a recording of myself reading The Enormous Space.

Apple’s attack on service workers

Apple aren’t the best at developer relations. But, bad as their communications can be, I’m willing to cut them some slack. After all, they’re not used to talking with the developer community.

John Wilander wrote a blog post that starts with some excellent news: Full Third-Party Cookie Blocking and More. Safari is catching up to Firefox and disabling third-party cookies by default. Wonderful! I’ve had third-party cookies disabled for a few years now, and while something occassionally breaks, it’s honestly a pretty great experience all around. Denying companies the ability to track users across sites is A Good Thing.

In the same blog post, John said that client-side cookies will be capped to a seven-day lifespan, as previously announced. Just to be clear, this only applies to client-side cookies. If you’re setting a cookie on the server, using PHP or some other server-side language, it won’t be affected. So persistent logins are still doable.

Then, in an audacious example of burying the lede, towards the end of the blog post, John announces that a whole bunch of other client-side storage technologies will also be capped to seven days. Most of the technologies are APIs that, like cookies, can be used to store data: Indexed DB, Local Storage, and Session Storage (though there’s no mention of the Cache API). At the bottom of the list is this:

Service Worker registrations

Okay, let’s clear up a few things here (because they have been so poorly communicated in the blog post)…

The seven day timer refers to seven days of Safari usage, not seven calendar days (although, given how often most people use their phones, the two are probably interchangable). So if someone returns to your site within a seven day period of using Safari, the timer resets to zero, and your service worker gets a stay of execution. Lucky you.

This only applies to Safari. So if your site has been added to the home screen and your web app manifest has a value for the “display” property like “standalone” or “full screen”, the seven day timer doesn’t apply.

That piece of information was missing from the initial blog post. Since the blog post was updated to include this clarification, some people have taken this to mean that progressive web apps aren’t affected by the upcoming change. Not true. Only progressive web apps that have been added to the home screen (and that have an appropriate “display” value) will be spared. That’s a vanishingly small percentage of progressive web apps, especially on iOS. To add a site to the home screen on iOS, you need to dig and scroll through the share menu to find the right option. And you need to do this unprompted. There is no ambient badging in Safari to indicate that a site is installable. Chrome’s install banner isn’t perfect, but it’s better than nothing.

Just a reminder: a progressive web app is a website that

  • runs on HTTPS,
  • has a service worker,
  • and a web manifest.

Adding to the home screen is something you can do with a progressive web app (or any other website). It is not what defines progressive web apps.

In any case, this move to delete service workers after seven days of using Safari is very odd, and I’m struggling to find the connection to the rest of the blog post, which is about technologies that can store data.

As I understand it, with the crackdown on setting third-party cookies, trackers are moving to first-party technologies. So whereas in the past, a tracking company could tell its customers “Add this script element to your pages”, now they have to say “Add this script element and this script file to your pages.” That JavaScript file can then store a unique idenitifer on the client. This could be done with a cookie, with Local Storage, or with Indexed DB, for example. But I’m struggling to understand how a service worker script could be used in this way. I’d really like to see some examples of this actually happening.

The best explanation I can come up with for this move by Apple is that it feels like the neatest solution. That’s neat as in tidy, not as in nifty. It is definitely not a nifty solution.

If some technologies set by a specific domain are being purged after seven days, then the tidy thing to do is purge all technologies from that domain. Service workers are getting included in that dragnet.

Now, to be fair, browsers and operating systems are free to clean up storage space as they see fit. Caches, Local Storage, Indexed DB—all of those are subject to eventually getting cleaned up.

So I was curious. Wanting to give Apple the benefit of the doubt, I set about trying to find out how long service worker registrations currently last before getting deleted. Maybe this announcement of a seven day time limit would turn out to be not such a big change from current behaviour. Maybe currently service workers last for 90 days, or 60, or just 30.


There was no time limit previously.

This is not a minor change. This is a crippling attack on service workers, a technology specifically designed to improve the user experience for return visits, whether it’s through improved performance or offline access.

I wouldn’t be so stunned had this announcement come with an accompanying feature that would allow Safari users to know when a website is a progressive web app that can be added to the home screen. But Safari continues to ignore the existence of progressive web apps. And now it will actively discourage people from using service workers.

If you’d like to give feedback on this ludicrous development, you can file a bug (down in the cellar in the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying “Beware of the Leopard”).

No doubt there will still be plenty of Apple apologists telling us why it’s good that Safari has wished service workers into the cornfield. But make no mistake. This is a terrible move by Apple.

I will say this though: given The Situation we’re all living in right now, some good ol’ fashioned Hot Drama by a browser vendor behaving badly feels almost comforting.