Tags: rel



Monday, August 7th, 2023

Relative times

Last week Phil posted a little update about his excellent site, ooh.directory:

If you’re in the habit of visiting the Recently Updated Blogs page, and leaving it open, the times when each blog was updated will now keep up with the relentless passing of time.

Does that make sense? “3 minutes ago” will change to “4 minutes ago” and so on and on and on, until you refresh the page.

I thought that was a nice little addition, and I immediately thought of The Session. There are time elements all over the site with relative times as the text content: 2 minutes ago, 7 hours ago, 1 year ago, and so on. Those strings of text are generated on the server. But I figured it would be nice enhancement to periodically update them in the browser after the page has loaded.

I viewed source to see how Phil was doing it. The code is nice and short, using a library called Day.js with a plug-in for relative time.

“Hang on”, I thought, “isn’t there some web standard for doing this kind of thing?” I had a vague memory of some JavaScript API for formatting dates and times.

Sure enough, we’ve now got the Intl.RelativeTimeFormat object. It’s got browser support across the board.

Here’s the code I wrote.

I’ve got a function that loops through all the time elements with datetime attributes. It compares the current timestamp to that value to get the elapsed time. Then that’s formatted using the format() method and output as innerText.

You need to tell the format() method which units you want to use: seconds, minutes, hours, days, etc. So there’s a little bit of looping to figure out which unit is most appropriate. If the elapsed time is less than a minute, use seconds. If the elapsed time is less than an hour, use minutes. If the elapsed time is less than a day, use hours. You get the idea.

It’s a pity there isn’t some kind of magic unit like “auto” to do this, but it’s not much extra code to figure it out.

Anyway, that function runs periodically using setInterval(). I’ve set it to run every 30 seconds in my gist. On The Session I’ve set it to one minute.

You’ll notice that I’m grabbing all the relevant time elements—using document.querySelector('time[datetime]')—every time the function is run. That may seem inefficient. Couldn’t I just grab them once and then keep them stored as an array? But I want this to work even if the page contents have been updated with Ajax. (Do people even say “Ajax” any more? Get off my lawn, you pesky kids!)

I think I’ve written this code in an abstract way so that you should be able to drop it into any web page. For the calculations to work, you’ll need to either make sure that your datetime attributes are using timezones. Or, if there’s no timezone info, UTC is assumed.

This was a fun little piece of functionality to play around with. Now I know a little more about this Intl.RelativeTimeFormat object. The way I’m using it as a classic example of progressive enhancement. If a browser doesn’t support it, or if my code breaks, it’s no big deal. The funtionality is a little bonus that almost nobody will notice anyway. Just a small delighter …if you’re the kind of person who finds it delightful when relative time strings automatically update.

Sunday, June 11th, 2023


Today was a good day. The weather was beautiful.

Jessica and I did a little bit of work in the garden—nothing too sweaty. Then Jessica cut my hair. It looks good. And it feels good to have my neck freed up.

We went for a Sunday roast at the nearest pub, which does a most excellent carvery. It was tasty and plentiful so after strolling home, I wanted to do nothing more than sit around.

I sat outside in the back garden under the dappled shade offered by the overhanging trees. I had a good book. I had my mandolin to hand. I’d reach for it occassionally to play a tune or two.

Coco the cat—not our cat—sat nearby, stretching her paws out lazily in the warm muggy air.

It was a good day.

Tuesday, January 24th, 2023

In between

I was chatting with my new colleague Alex yesterday about a link she had shared in Slack. It was the Nielsen Norman Group’s annual State of Mobile User Experience report.

There’s nothing too surprising in there, other than the mention of Apple’s app clips and Google’s instant apps.

Remember those?

Me neither.

Perhaps I lead a sheltered existence, but as an iPhone user, I don’t think I’ve come across a single app clip in the wild.

I remember when they were announced. I was quite worried about them.

See, the one thing that the web can (theoretically) offer that native can’t is instant access to a resource. Go to this URL—that’s it. Whereas for a native app, the flow is: go to this app store, find the app, download the app.

(I say that the benefit is theoretical because the website found at the URL should download quickly—the reality is that the bloat of “modern” web development imperils that advantage.)

App clips—and instant apps—looked like a way to route around the convoluted install process of native apps. That’s why I was nervous when they were announced. They sounded like a threat to the web.

In reality, the potential was never fulfilled (if my own experience is anything to go by). I wonder why people didn’t jump on app clips and instant apps?

Perhaps it’s because what they promise isn’t desirable from a business perspective: “here’s a way for users to accomplish their tasks without downloading your app.” Even though app clips can in theory be a stepping stone to installing the full app, from a user’s perspective, their appeal is the exact opposite.

Or maybe they’re just too confusing to understand. I think there’s an another technology that suffers from the same problem: progressive web apps.

Hear me out. Progressive web apps are—if done well—absolutely amazing. You get all of the benefits of native apps in terms of UX—they even work offline!—but you retain the web’s frictionless access model: go to a URL; that’s it.

So what are they? Are they websites? Yes, sorta. Are they apps? Yes, sorta.

That’s confusing, right? I can see how app clips and instant apps sound equally confusing: “you can use them straight away, like going to a web page, but they’re not web pages; they’re little bits of apps.”

I’m mostly glad that app clips never took off. But I’m sad that progressive web apps haven’t taken off more. I suspect that their fates are intertwined. Neither suffer from technical limitations. The problem they both face is inertia:

The technologies are the easy bit. Getting people to re-evaluate their opinions about technologies? That’s the hard part.

True of progressive web apps. Equally true of app clips.

But when I was chatting to Alex, she made me look at app clips in a different way. She described a situation where somebody might need to interact with some kind of NFC beacon from their phone. Web NFC isn’t supported in many browsers yet, so you can’t rely on that. But you don’t want to make people download a native app just to have a quick interaction. In theory, an app clip—or instant app—could do the job.

In that situation, app clips aren’t a danger to the web—they’re polyfills for hardware APIs that the web doesn’t yet support!

I love having my perspective shifted like that.

The specific situations that Alex and I were discussing were in the context of museums. Musuems offer such interesting opportunities for the physical and the digital to intersect.

Remember the pen from Cooper Hewitt? Aaron spoke about it at dConstruct 2014—a terrific presentation that’s well worth revisiting and absorbing.

The other dConstruct talk that’s very relevant to this liminal space between the web and native apps is the 2012 talk from Scott Jenson. I always thought the physical web initiative had a lot of promise, but it may have been ahead of its time.

I loved the thinking behind the physical web beacons. They were deliberately dumb, much like the internet itself. All they did was broadcast a URL. That’s it. All the smarts were to be found at the URL itself. That meant a service could get smarter over time. It’s a lot easier to update a website than swap out a piece of hardware.

But any kind of technology that uses Bluetooth, NFC, or other wireless technology has to get over the discovery problem. They’re invisible technologies, so by default, people don’t know they’re even there. But if you make them too discoverable— intrusively announcing themselves like one of the commercials in Minority Report—then they’re indistinguishable from spam. There’s a sweet spot of discoverability right in the middle that’s hard to get right.

Over the past couple of years—accelerated by the physical distancing necessitated by The Situation—QR codes stepped up to the plate.

They still suffer from some discoverability issues. They’re not human-readable, so you can’t be entirely sure that the URL you’re going to go to isn’t going to be a Rick Astley video. But they are visible, which gives them an advantage over hidden wireless technologies.

They’re cheaper too. Printing a QR code sticker costs less than getting a plastic beacon shipped from China.

QR codes turned out to be just good enough to bridge the gap between the physical and digital for those one-off interactions like dining outdoors during a pandemic:

I can see why they chose the web over a native app. Online ordering is the only way to place your order at this place. Telling people “You have to go to this website” …that seems reasonable. But telling people “You have to download this app” …that’s too much friction.

Ironically, the nail in the coffin for app clips and instant apps might’ve been hammered in by Apple and Google when they built QR-code recognition into their camera software.

Tuesday, December 27th, 2022

How We Verified Ourselves on Mastodon — and How You Can Too – The Markup

It gives me warm fuzzies to see an indie web building block like rel="me" getting coverage like this.

Monday, November 21st, 2022

Why you should never use px to set font-size in CSS - Josh Collinsworth blog


em and rem work with the user’s font size; px completely overrides it.

Thursday, September 8th, 2022

How To Improve Largest Contentful Paint for Faster Load Times - Calibre

A no-nonsense checklist of good performance advice from Karolina.

Tuesday, August 23rd, 2022

Work ethics

If you’re travelling around Ireland, you may come across some odd pieces of 19th century architecture—walls, bridges, buildings and roads that serve no purpose. They date back to The Great Hunger of the 1840s. These “famine follies” were the result of a public works scheme.

The thinking went something like this: people are starving so we should feed them but we can’t just give people food for nothing so let’s make people do pointless work in exchange for feeding them (kind of like an early iteration of proof of work for cryptobollocks on blockchains …except with a blockchain, you don’t even get a wall or a road, just ridiculous amounts of wasted energy).

This kind of thinking seems reprehensible from today’s perspective. But I still see its echo in the work ethic espoused by otherwise smart people.

Here’s the thing: there’s good work and there’s working hard. What matters is doing good work. Often, to do good work you need to work hard. And so people naturally conflate the two, thinking that what matters is working hard. But whether you work hard or not isn’t actually what’s important. What’s important is that you do good work.

If you can do good work without working hard, that’s not a bad thing. In fact, it’s great—you’ve managed to do good work and do it efficiently! But often this very efficiency is treated as laziness.

Sensible managers are rightly appalled by so-called productivity tracking because it measures exactly the wrong thing. Those instruments of workplace surveillance measure inputs, not outputs (and even measuring outputs is misguided when what really matters are outcomes).

They can attempt to measure how hard someone is working, but they don’t even attempt to measure whether someone is producing good work. If anything, they actively discourage good work; there’s plenty of evidence to show that more hours equates to less quality.

I used to think that must be some validity to the belief that hard work has intrinsic value. It was a position that was espoused so often by those around me that it seemed a truism.

But after a few decades of experience, I see no evidence for hard work as an intrinsically valuable activity, much less a useful measurement. If anything, I’ve seen the real harm that can be caused by tying your self-worth to how much you’re working. That way lies burnout.

We no longer make people build famine walls or famine roads. But I wonder how many of us are constructing little monuments in our inboxes and calendars, filling those spaces with work to be done in an attempt to chase the rewards we’ve been told will result from hard graft.

I’d rather spend my time pursuing the opposite: the least work for the most people.

Tuesday, August 16th, 2022

Alternative stylesheets

My website has different themes you can choose from. I don’t just mean a dark mode. These themes all look very different from one another.

I assume that 99.99% of people just see the default theme, but I keep the others around anyway. Offering different themes was originally intended as a way of showcasing the power of CSS, and specifically the separation of concerns between structure and presentation. I started doing this before the CSS Zen Garden was created. Dave really took it to the next level by showing how the same HTML document could be styled in an infinite number of ways.

Each theme has its own stylesheet. I’ve got a very simple little style switcher on every page of my site. Selecting a different theme triggers a page refresh with the new styles applied and sets a cookie to remember your preference.

I also list out the available stylesheets in the head of every page using link elements that have rel values of alternate and stylesheet together. Each link element also has a title attribute with the name of the theme. That’s the standard way to specify alternative stylesheets.

In Firefox you can switch between the specified stylesheets from the View menu by selecting Page Style (notice that there’s also a No style option—very handy for checking your document structure).

Other browsers like Chrome and Safari don’t do anything with the alternative stylesheets. But they don’t ignore them.

Every browser makes a network request for each alternative stylesheet. The request is non-blocking and seems to be low priority, which is good, but I’m somewhat perplexed by the network request being made at all.

I get why Firefox is requesting those stylesheets. It’s similar to requesting a print stylesheet. Even if the network were to drop, you still want those styles available to the user.

But I can’t think of any reason why Chrome or Safari would download the alternative stylesheets.

Thursday, June 30th, 2022


I no longer have Covid. I am released from isolation.

Alas, my negative diagnosis came too late for me to make it to UX London. But that’s okay—by the third and final day of the event, everything was running smooth like buttah! Had I shown up, I would’ve just got in the way. The Clearleft crew ran the event like a well-oiled machine.

I am in the coronaclear just in time to go away for a week. My original thinking was this would be my post-UX-London break to rest up for a while, but it turns out I’ve been getting plenty of rest during UX London.

I’m heading to the west coast of Ireland for The Willie Clancy Summer School, a trad music pilgrimage.

Jessica and I last went to Willie Week in 2019. We had a great time and I distinctly remember thinking “I’m definitely coming back next year!”

Well, a global pandemic put paid to that. The event ran online for the past two years. But now that it’s back for real, I wouldn’t miss it for the world.

My mandolin and I are bound for Miltown Malbay!

Monday, April 4th, 2022

Understanding Layout Algorithms

Josh is great at explaining tricky concepts and here he’s really set himself a challenge: explaining layout modes in CSS.

Monday, January 17th, 2022

A Quick History of Digital Communication Before the Internet - Eager Blog

A potted history of communication networks from the pony express and the telegraph to ethernet and wi-fi.

Thursday, December 2nd, 2021


Now you can play a demo of Townscaper right in your browser.

There goes your productivity.

Tuesday, October 19th, 2021

Software developers have stopped caring about reliability

My web browser has been perfectly competent at submitting HTML forms for the past 28 years, but for some stupid reason some asshole developer decided to reimplement all of the form semantics in JavaScript, and now I can’t pay my electricity bill without opening up the dev tools. Imagine what it’s like to not know how to do that. Imagine if you were blind.

Folks, this is not okay. Our industry is characterized by institutional recklessness and a callous lack of empathy for our users.

Monday, September 20th, 2021

An Idea from Computer Science That Can Change Your Life – Jorge Arango

Applying Postel’s Law to relationships:

I aspire to be conservative in what and how I share (i.e., avoid drama) while understanding that other people will say all sorts of unmindful things.

Thursday, August 19th, 2021

Is Safari the new Internet Explorer?

The transcript from the latest episode of the HTTP 203 podcast is well worth perusing.

  • Internet Explorer halted development, no innovation. Would you say Safari is the new IE?
  • There was loads of stuff missing. Is Safari the new IE?
  • My early career was built on knowing the bugs in IE6 and how to solve them. Is Safari the new IE?
  • Internet Explorer 6, it had a really slow JavaScript engine, performance was bad in that browser. Is Safari the new IE?
  • Internet Explorer had a fairly cavalier attitude towards web standards. Is Safari the new IE?
  • Back in the day that we had almost no communication whatsoever. Is Safari the new IE?
  • Slow-release cycle. Is Safari the new IE?

Tuesday, August 17th, 2021


I was moaning about Safari recently. Specifically I was moaning about the ridiculous way that browser updates are tied to operating system updates.

But I felt bad bashing Safari. It felt like a pile-on. That’s because a lot of people have been venting their frustrations with Safari recently:

I think it’s good that people share their frustrations with browsers openly, although I agree with Baldur Bjarnason that’s good to avoid Kremlinology and the motivational fallacy when blogging about Apple.

It’s also not helpful to make claims like “Safari is the new Internet Explorer!” Unless, that is, you can back up the claim.

On a recent episode of the HTTP 203 podcast, Jake and Surma set out to test the claim that Safari is the new IE. They did it by examining Safari according to a number of different measurements and comparing it to the olden days of Internet Explorer. The result is a really fascinating trip down memory lane along with a very nuanced and even-handed critique of Safari.

And the verdict? Well, you’ll just to have to listen to the podcast episode.

If you’d rather read the transcript, tough luck. That’s a real shame because, like I said, it’s an excellent and measured assessment. I’d love to add it to the links section of my site, but I can’t do that in good conscience while it’s inaccessible to the Deaf community.

When I started the Clearleft podcast, it was a no-brainer to have transcripts of every episode. Not only does it make the content more widely available, but it also makes it easier for people to copy and paste choice quotes.

Still, I get it. A small plucky little operation like Google isn’t going to have the deep pockets of a massive corporation like Clearleft. But if Jake and Surma were to open up a tip jar, I’d throw some money in to get HTTP 203 transcribed (I recommend getting Tina Pham to do it—she’s great!).

I apologise for my note of sarcasm there. But I share because I care. It really is an excellent discussion; one that everyone should be able to access.

Update: the bug with that episode of the HTTP 203 podcast has been fixed. Here’s the transcript! And all future episodes will have transcripts too:

Sunday, August 8th, 2021


I mentioned recently that there might be quite a difference in tone between my links and my journal here on my website:

’Sfunny, when I look back at older journal entries they’re often written out of frustration, usually when something in the dev world is bugging me. But when I look back at all the links I’ve bookmarked the vibe is much more enthusiastic, like I’m excitedly pointing at something and saying “Check this out!” I feel like sentiment analyses of those two sections of my site would yield two different results.

My journal entries have been even more specifically negative of late. I’ve been bitchin’ and moanin’ about web browsers. But at least I’m an equal-opportunities bitcher and moaner.

I wish my journal weren’t so negative, but my mithering behaviour has been been encouraged. On more than one occasion, someone I know at a browser company has taken me aside to let me know that I should blog about any complaints I might have with their browser. It sounds counterintuitive, I know. But these blog posts can give engineers some ammunition to get those issues prioritised and fixed.

So my message to you is this: if there’s something about a web browser that you’re not happy with (or, indeed, if there’s something you’re really happy with), take the time to write it down and publish it.

Publish it on your website. You could post your gripes on Twitter but whinging on Jack’s website is just pissing in the wind. And I suspect you also might put a bit more thought into a blog post on your own site.

I know it’s a cliché to say that browser makers want to hear from developers—and I’m often cynical about it myself—but they really do want to know what we think. Share your thoughts. I’ll probably end up linking to what you write.

Thursday, August 5th, 2021

Updating Safari

Safari has been subjected to a lot of ire recently. Most of that ire has been aimed at the proposed changes to the navigation bar in Safari on iOS—moving it from a fixed top position to a floaty bottom position right over the content you’re trying to interact with.


It remains to be seen whether this change will actually ship. That’s why it’s in beta—to gather all the web’s hot takes first.

But while this very visible change is dominating the discussion, invisible changes can be even more important. Or in the case of Safari, the lack of changes.

Compared to other browsers, Safari lags far behind when it comes to shipping features. I’m not necessarily talking about cutting-edge features either. These are often standards that have been out for years. This creates a gap—albeit an invisible one—between Safari and other browsers.

Jorge Arango has noticed this gap:

I use Safari as my primary browser on all my devices. I like how Safari integrates with the rest of the OS, its speed, and privacy features. But, alas, I increasingly have issues rendering websites and applications on Safari.

That’s the perspective of an end-user. Developers who have to deal with the gap in features are more, um, strident in their opinions. Perry Sun wrote For developers, Apple’s Safari is crap and outdated:

Don’t get me wrong, Safari is very good web browser, delivering fast performance and solid privacy features.

But at the same time, the lack of support for key web technologies and APIs has been both perplexing and annoying at the same time.

Alas, that post also indulges in speculation about Apple’s motives which always feels a bit too much like a conspiracy theory to me. Baldur Bjarnason has more to say on that topic in his post Kremlinology and the motivational fallacy when blogging about Apple. He also points to a good example of critiquing Safari without speculating about motives: Dave’s post One-offs and low-expectations with Safari, which documents all the annoying paper cuts inflicted by Safari’s “quirks.”

Another deep dive that avoids speculating about motives comes from Tim Perry: Safari isn’t protecting the web, it’s killing it. I don’t agree with everything in it. I think that Apple—and Mozilla’s—objections to some device APIs are informed by a real concern about privacy and security. But I agree with his point that it’s not enough to just object; you’ve got to offer an alternative vision too.

That same post has a litany of uncontroversial features that shipped in Safari looong after they shipped in other browsers:

Again: these are not contentious features shipping by only Chrome, they’re features with wide support and no clear objections, but Safari is still not shipping them until years later. They’re also not shiny irrelevant features that “bloat the web” in any sense: each example I’ve included above primarily improving core webpage UX and performance. Safari is slowing that down progress here.

But perhaps most damning of all is how Safari deals with bugs.

A recent release of Safari shipped with a really bad Local Storage bug. The bug was fixed within a day. Yay! But the fix won’t ship until …who knows?

This is because browser updates are tied to operating system updates. Yes, this is just like the 90s when Microsoft claimed that Internet Explorer was intrinsically linked to Windows (a tactic that didn’t work out too well for them in the subsequent court case).

I don’t get it. I’m pretty sure that other Apple products ship updates and fixes independentally of OS releases. I’m sure I’ve received software updates for Keynote, Garage Band, and other pieces of software made by Apple.

And yet, of all the applications that need a speedy update cycle—a user agent for the World Wide Web—Apple’s version is needlessly delayed by the release cycle of the entire operating system.

I don’t want to speculate on why this might be. I don’t know the technical details. But I suspect that the root cause might not be technical in nature. Apple have always tied their browser updates to OS releases. If Google’s cardinal sin is avoiding anything “Not Invented Here”, Apple’s downfall is “We’ve always done it this way.”

Evergreen browsers update in the background, usually at regular intervals. Firefox is an evergreen browser. Chrome is an evergreen browser. Edge is an evergreen browser.

Safari is not an evergreen browser.

That’s frustrating when it comes to new features. It’s unforgivable when it comes to bugs.

At least on Apple’s desktop computers, users have the choice to switch to a different browser. But on Apple’s mobile devices, users have no choice but to use Safari’s rendering engine, bugs and all.

As I wrote when I had to deal with one of Safari’s bugs:

I wish that Apple would allow other rendering engines to be installed on iOS devices. But if that’s a hell-freezing-over prospect, I wish that Safari updates weren’t tied to operating system updates.

Tuesday, March 23rd, 2021

Service worker weirdness in Chrome

I think I’ve found some more strange service worker behaviour in Chrome.

It all started when I was checking out the very nice new redesign of WebPageTest. I figured while I was there, I’d run some of my sites through it. I passed in a URL from The Session. When the test finished, I noticed that the “screenshot” tab said that something was being logged to the console. That’s odd! And the file doing the logging was the service worker script.

I fired up Chrome (which isn’t my usual browser), and started navigating around The Session with dev tools open to see what appeared in the console. Sure enough, there was a failed fetch attempt being logged. The only time my service worker script logs anything is in the catch clause of fetching pages from the network. So Chrome was trying to fetch a web page, failing, and logging this error:

The service worker navigation preload request failed with a network error.

But all my pages were loading just fine. So where was the error coming from?

After a lot of spelunking and debugging, I think I’ve figured out what’s happening…

First of all, I’m making use of navigation preloads in my service worker. That’s all fine.

Secondly, the website is a progressive web app. It has a manifest file that specifies some metadata, including start_url. If someone adds the site to their home screen, this is the URL that will open.

Thirdly, Google recently announced that they’re tightening up the criteria for displaying install prompts for progressive web apps. If there’s no network connection, the site still needs to return a 200 OK response: either a cached copy of the URL or a custom offline page.

So here’s what I think is happening. When I navigate to a page on the site in Chrome, the service worker handles the navigation just fine. It also parses the manifest file I’ve linked to and checks to see if that start URL would load if there were no network connection. And that’s when the error gets logged.

I only noticed this behaviour because I had specified a query string on my start URL in the manifest file. Instead of a start_url value of /, I’ve set a start_url value of /?homescreen. And when the error shows up in the console, the URL being fetched is /?homescreen.

Crucially, I’m not seeing a warning in the console saying “Site cannot be installed: Page does not work offline.” So I think this is all fine. If I were actually offline, there would indeed be an error logged to the console and that start_url request would respond with my custom offline page. It’s just a bit confusing that the error is being logged when I’m online.

I thought I’d share this just in case anyone else is logging errors to the console in the catch clause of fetches and is seeing an error even when everything appears to be working fine. I think there’s nothing to worry about.

Update: Jake confirmed my diagnosis and agreed that the error is a bit confusing. The good news is that it’s changing. In Chrome Canary the error message has already been updated to:

DOMException: The service worker navigation preload request failed due to a network error. This may have been an actual network error, or caused by the browser simulating offline to see if the page works offline: see https://w3c.github.io/manifest/#installability-signals

Much better!

Saturday, December 12th, 2020

Kevin Kelly on Why Technology Has a Will | Palladium Magazine

Technologies are always coming out of networks that require other related ideas to have the next one. The fact that we have simultaneous independent invention as a norm works against the idea of the heroic inventor, that we’re dependent on them for inventions. These things will come when all the other pieces are ready.