Journal tags: progress

I must admit, when Jake told me he was leaving Google, I got very worried about the future of the View Transitions API.

To recap: Chrome shipped support for the API, but only for single page apps. That had me worried:

If the View Transitions API works across page navigations, it could be the single best thing to happen to the web in years.

If the View Transitions API only works for single page apps, it could be the single worst thing to happen to the web in years.

Well, the multi-page version still hasn’t yet shipped in Chrome stable, but it is available in Chrome Canary behind a flag, so it looks like it’s almost here!

Robin took the words out of my mouth:

Anyway, even this cynical jerk is excited about this thing.

Are you the kind of person who flips feature flags on in nightly builds to test new APIs?

Me neither.

But I made an exception for the View Transitions API. So did Dave:

I think the most telling predictor for the success of the multi-page View Transitions API – compared to all other proposals and solutions that have come before it – is that I actually implemented this one. Despite animations being my bread and butter for many years, I couldn’t be arsed to even try any of the previous generation of tools.

Dave’s post is an excellent step-by-step introduction to using view transitions on your website. To recap:

Enable these two flags in Chrome Canary:

chrome://flags#view-transition
chrome://flags#view-transition-on-navigation

Then add this meta element to the head of your website:

<meta name="view-transition" content="same-origin">

You could stop there. If you navigate around your site, you’ll see that the navigations now fade in and out nicely from one page to another.

But the real power comes with transitioning page elements. Basically, you want to say “this element on this page should morph into that element on that page.” And when I say morph, I mean morph. As Dave puts it:

Behind the scenes the browser is rasterizing (read: making an image of) the before and after states of the DOM elements you’re transitioning. The browser figures out the differences between those two snapshots and tweens between them similar to Apple Keynote’s “Magic Morph” feature, the liquid metal T-1000 from Terminator 2: Judgement Day, or the 1980s cartoon series Turbo Teen.

If those references are lost on you, how about the popular kids book series Animorphs?

Some classic examples would be:

• A thumbnail of a video on one page morphs into the full-size video on the next page.
• A headline and snippet of an article on one page morphs into the full article on the next page.

I’ve added view transitions to The Session. Where I’ve got index pages with lists of titles, each title morphs into the heading on the next page.

Again, Dave’s post was really useful here. Each transition needs a unique name, so I used Dave’s trick of naming each transition with the ID of the individual item being linked to.

In the recordings section, for example, there might be a link like this on the index page:

<a href="/recordings/7812" style="view-transition-name: recording-7812">The Banks Of The Moy</a>

Which, if you click on it, takes you to the page with this heading:

<h1><span style="view-transition-name: recording-7812">The Banks Of The Moy</span></h1>

Why the span? Well, like Dave, I noticed some weird tweening happening between block and inline elements. Dave solved the problem with width: fit-content on the block-level element. I just stuck in an extra inline element.

Anyway, the important thing is that the name of the view transition matches: recording-7812.

I also added a view transition to pages that have maps. The position of the map might change from page to page. Now there’s a nice little animation as you move from one page with a map to another page with a map.

That’s all good, but I found myself wishing that I could just have those enhancements. Every single navigation on the site was triggering a fade in and out—the default animation. I wondered if there was a way to switch off the default fading.

There is! That default animation is happening on a view transition named root. You can get rid of it with this snippet of CSS:

::view-transition-image-pair(root) {
  isolation: auto;
}
::view-transition-old(root),
::view-transition-new(root) {
  animation: none;
  mix-blend-mode: normal;
  display: block;
}

Voila! Now only the view transitions that you name yourself will get applied.

You can adjust the timing, the easing, and the animation properites of your view transitions. Personally, I was happy with the default morph.

In fact, that’s one of the things I like about this API. It’s another good example of declarative design. I say what I want to happen, but I don’t need to specify the details. I’ll let the browser figure all that out.

That’s what’s got me so excited about this API. Yes, it’s powerful. But just as important, it’s got a very low barrier to entry.

Chris has gathered a bunch of examples together in his post Early Days Examples of View Transitions. Have a look around to get some ideas.

If you like what you see, I highly encourage you to add view transitions to your website now.

“But wait,” I hear you cry, “this isn’t supported in any public-facing browser yet!”

To which, I respond “So what?” It’s a perfect example of progressive enhancement. Adding one meta element and a smidgen of CSS will do absolutely no harm to your website. And while no-one will see your lovely view transitions yet, once browsers do start shipping with support for the API, your site will automatically get better.

Your website will be enhanced. Progressively.

Update: Simon Pieters quite rightly warns against adding view transitions to live sites before the API is done:

in general, using features before they ship in a browser isn’t a great idea since it can poison the feature with legacy content that might break when the feature is enabled. This has happened several times and renames or so were needed.

Good point. I must temper my excitement with pragmatism. Let me amend my advice:

I highly encourage you to experiment with view transitions on your website now.

The most cartoonish misrepresentation of progressive enhancement is that it means making everything work without JavaScript.

No. Progressive enhancement means making sure your core functionality works without JavaScript.

In my book Resilient Web Design, I quoted Wilto:

Lots of cool features on the Boston Globe don’t work when JS breaks; “reading the news” is not one of them.

That’s an example where the core functionality is readily identifiable. It’s a newspaper. The core functionality is reading the news.

It isn’t always so straightforward though. A lot of services that self-identify as “apps” will claim that even their core functionality requires JavaScript.

Surely I don’t expect Gmail or Google Docs to provide core functionality without JavaScript?

In those particular cases, I actually do. I believe that a textarea in a form would do the job nicely. But I get it. That might take a lot of re-engineering.

So how about this compromise…

Your app should work in a read-only mode without JavaScript.

Without JavaScript I should still be able to read my email in Gmail, even if you don’t let me compose, reply, or organise my messages.

Without JavaScript I should still be able to view a document in Google Docs, even if you don’t let me comment or edit the document.

Even with something as interactive as Figma or Photoshop, I think I should still be able to view a design file without JavaScript.

Making this distinction between read-only mode and read/write mode could be very useful, especially at the start of a project.

Begin by creating the read-only mode that doesn’t require JavaScript. That alone will make for a solid foundation to build upon. Now you’ve built a fallback for any unexpected failures.

Now start adding the read/write functionally. You’re enhancing what’s already there. Progressively.

Heck, you might even find some opportunities to provide some read/write functionality that doesn’t require JavaScript. But if JavaScript is needed, that’s absolutely fine.

So if you’re about to build a web app and you’re pretty sure it requires JavaScript, why not pause and consider whether you can provide a read-only version.

Robin penned a little love letter to the details element. I agree. It is a joyous piece of declarative power.

That said, don’t go overboard with it. It’s not a drop-in replacement for more complex widgets. But it is a handy encapsulation of straightforward progressive disclosure.

Just last week I added a couple of more details elements to The Session …kind of. There’s a bit of server-side conditional logic involved to determine whether details is the right element.

When you’re looking at a tune, one of the pieces of information you see is how many recordings there of that tune. Now if there are a lot of recordings, then there’s some additional information about which other tunes this one gets recorded with. That information is extra. Mere details, if you will.

You can see it in action on this tune listing. Thanks to the details element, the extra information is available to those who want it, but by default that information is tucked away—very handy for not clogging up that part of the page.

<details>
<summary>There are 181 recordings of this tune.</summary>
This tune has been recorded together with
<ul>
<li>…</li>
<li>…</li>
<li>…</li>
</ul>
</details>

Likewise, each tune page includes any aliases for the tune (in Irish music, the same tune can have many different titles—and the same title can be attached to many different tunes). If a tune has just a handful of aliases, they’re displayed in situ. But once you start listing out more than twenty names, it gets overwhelming.

The details element rides to the rescue once again.

Compare the tune I mentioned above, which only has a few aliases, to another tune that is known by many names.

Again, the main gist is immediately available to everyone—how many aliases are there? But if you want to go through them all, you can toggle that details element open.

You can effectively think of the summary element as the TL;DR of HTML.

<details>
<summary>There are 31 other names for this tune.</summary>
<p>Also known as…</p>
</details>

There’s another classic use of the details element: frequently asked questions. In the case of The Session, I’ve marked up the house rules and FAQs inside details elements, with the rule or question as the summary.

But there’s one house rule that’s most important (“Be civil”) so that details element gets an additional open attribute.

<details open>
<summary>Be civil</summary>
<p>Contributions should be constructive and polite, not mean-spirited or contributed with the intention of causing trouble.</p>
</details>

Push notifications are finally arriving on iOS—hallelujah! Like I said last year, this is my number one wish for the iPhone, though not because I personally ever plan to use the feature:

When I’m evangelising the benefits of building on the open web instead of making separate iOS and Android apps, I inevitably get asked about notifications. As long as mobile Safari doesn’t support them—even though desktop Safari does—I’m somewhat stumped. There’s no polyfill for this feature other than building an entire native app, which is a bit extreme as polyfills go.

With push notifications in mobile Safari, the arguments for making proprietary apps get weaker. That’s good.

The announcement post is a bit weird though. It never uses the phrase “progressive web apps”, even though clearly the entire article is all about progressive web apps. I don’t know if this down to Not-Invented-Here syndrome by the Apple/Webkit team, or because of genuine legal concerns around using the phrase.

Instead, there are repeated references to “Home Screen apps”. This distinction makes some sense though. In order to use web push on iOS, your website needs to be added to the home screen.

I think that would be fair enough, if it weren’t for the fact that adding a website to the home screen remains such a hidden feature that even power users would be forgiven for not knowing about it. I described the steps here:

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

As long as this remains the case, we can expect usage of web push on iOS to be vanishingly low. Hardly anyone is going to add a website to their home screen when their web browser makes it so hard.

If you’d like to people to install your progressive web app, you’ll almost certainly need to prompt people to do so. Here’s the page I made on thesession.org with instructions on how to add to home screen. I link to it from the home page of the site.

I wish that pages like that weren’t necessary. It’s not the best user experience. But as long as mobile Safari continues to bury the home screen option, we don’t have much choice but to tackle this ourselves.

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.

It’s been almost two years since I added audio playback on The Session. The interface is quite straightforward. For any tune setting, there’s a button that says “play audio”. When you press that button, audio plays and the button’s text changes to “pause audio.”

By updating the button’s text like this, I’m updating the button’s accessible name. In other situations, where the button text doesn’t change, you can indicate whether a button is active or not by toggling the aria-pressed attribute. I’ve been doing that on the “share” buttons that act as the interface for a progressive disclosure. The label on the button—“share”—doesn’t change when the button is pressed. For that kind of progressive disclosure pattern, the button also has an aria-controls and aria-expanded attribute.

From all the advice I’ve read about button states, you should either update the accessible name or change the aria-pressed attribute, but not both. That would lead to the confusing situation of having a button labelled “pause audio” as having a state of “pressed” when in fact the audio is playing.

That was all fine until I recently added some more functionality to The Session. As well as being able to play back audio, you can now adjust the tempo of the playback speed. The interface element for this is a slider, input type="range".

But this means that the “play audio” button now does two things. It plays the audio, but it also acts as a progressive disclosure control, revealing the tempo slider. The button is simultaneously a push button for playing and pausing music, and a toggle button for showing and hiding another interface element.

So should I be toggling the aria-pressed attribute now, even though the accessible name is changing? Or is it enough to have the relationship defined by aria-controls and the state defined by aria-expanded?

Based on past experience, my gut feeling is that I’m probably using too much ARIA. Maybe it’s an anti-pattern to use both aria-expanded and aria-pressed on a progressive disclosure control.

I’m kind of rubber-ducking here, and now that I’ve written down what I’m thinking, I’m pretty sure I’m going to remove the toggling of aria-pressed in any situation where I’m already toggling aria-expanded.

What I really need to do is enlist the help of actual screen reader users. There are a number of members of The Session who use screen readers. I should get in touch and see if the new functionality makes sense to them.

I’ve mentioned before that I don’t enable notifications on my phone. Text messages are the only exception. I don’t want to get notified if a new email arrives (I avoid email on my phone completely) and I certainly don’t want some social media app telling me somebody liked or faved something.

But the number one feature I’d like to see in Safari on iOS is web notifications.

It’s not for me personally, see. It’s because it’s the number one reason why people are choosing not to go all in progressive web apps.

Safari on iOS is the last holdout. But that equates to enough marketshare that many companies feel they can’t treat notifications as a progressive enhancement. While I may not agree with that decision myself, I get it.

When I’m evangelising the benefits of building on the open web instead of making separate iOS and Android apps, I inevitably get asked about notifications. As long as mobile Safari doesn’t support them—even though desktop Safari does—I’m somewhat stumped. There’s no polyfill for this feature other than building an entire native app, which is a bit extreme as polyfills go.

And of course, unlike on your Mac, you don’t have the option of using a different browser on your iPhone. As long as mobile Safari doesn’t support web notifications, nothing on iOS can support web notifications.

I’ve got progressive web apps on the home screen of my phone that match their native equivalents feature-for-feature. Twitter. Instagram. They’re really good. In some ways they’re superior to the native apps; the Twitter website is much calmer, and the Instagram website has no advertising. But if I wanted to get notifications from any of those sites, I’d have to keep the native apps installed just for that one feature.

So in the spirit of complaining about web browsers in a productive way, I just want to throw this plea out there: Apple, please support web notifications in mobile Safari!

The good news is that web notifications on iOS might be on their way. Huzzah!

Alas, we’re reliant on Maximiliano’s detective work to even get a glimpse of a future feature like this. Apple has no public roadmap for Safari. There’s this status page on the Webkit blog but it’s incomplete—web notifications don’t appear at all. In any case, WebKit and Safari aren’t the same thing. The only way of knowing if a feature might be implemented in Safari is if it shows up in Safari Technology Preview, at which point it’s already pretty far along.

So while my number one feature request for mobile Safari is web notifications, a close second would be a public roadmap.

It only seems fair. If Apple devrels are asking us developers what features we’d like to see implemented—as they should!—then shouldn’t those same developers also be treated with enough respect to share a roadmap with them? There’s not much point in us asking for features if, unbeknownst to us, that feature is already being worked on.

But, like I said, my number one request remains: web notifications on iOS …please!

Dave recently wrote some good advice about what to do—and what not to do—when it comes to complaining about web browsers. I wrote something on this topic a little while back:

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

To summarise Dave’s advice, avoid conspiracy theories and snark; stick to specifics instead.

It’s very good advice that I should heed (especially the bit about avoiding snark). In that spirit, I’d like to document what I think is a bug on iOS.

I don’t need to name the specific browser, because there is basically only one browser allowed on iOS. That’s not snark; that’s a statement of fact.

This bug involves navigating from a progressive web app that has been installed on your home screen to an external web view.

To illustrate the bug, I’ll use the example of The Session. If you want to recreate the bug, you’ll need to have an account on The Session. Let me know if you want to set up a temporary account—I can take care of deleting it afterwards.

Here are the steps:

1. Navigate to thesession.org in Safari on an iOS device.
2. Add the site to your home screen.
3. Open the installed site from your home screen—it will launch in standalone mode.
4. Log in with your username and password.
5. Using the site menu, navigate to the links section of the site.
6. Click on any external link.
7. After the external link opens in a web view, tap on “Done” to close the web view.

Expected behaviour: you are returned to the page you were on with no change of state.

Actual behaviour: you are returned to the page you were on but you are logged out.

So the act of visiting an external link in a web view while in a progressive web app in standalone mode seems to cause a loss of cookie-based authentication.

This isn’t permanent. Clicking on any internal link restores the logged-in state.

It is surprising though. My mental model for opening an external link in a web view is that it sits “above” the progressive web app, which remains in stasis “behind” it. But the page must actually be reloading, either when the web view is opened or when the web view is closed. And that reload is behaving like a fetch event without credentials.

Anyway, that’s my bug report. It may already be listed somewhere on the WebKit Bugzilla but I lack the deductive skills to find it. I’m not even sure if that’s the right place for this kind of bug. It might be specific to the operating system rather than the rendering engine.

This isn’t a high priority bug, but it is one of those cumulatively annoying software paper cuts.

Hope this helps!

I wrote about how I created a page on The Session with instructions for installing the site to your home screen. When I said that I included screenshots on that page, I may have underplayed the effort involved. It was real faff.

I’ve got an iPhone so generating screenshots (and video) from that wasn’t too bad. But I don’t have access to an Android phone. I found myself scouring the web for templates that I could use to mockup a screenshot of the address bar.

That got me thinking…

Wouldn’t it be cool if there were a service that generated those screenshots for you? You give it a URL, and it spits out screenshots of the site complete with overlays showing the installation flow on Android and iOS. It could even generate the img markup, complete with differently-scaled images for the srcset attribute.

Download the images. Copy that markup. Paste it into a page on your site. Boom! Now you’ve got somewhere to point your visitors to if you’d like them to install your progressive web app.

There are already some services out there for generating screenshots of mobile phones but they’re missing is the menu overlays for adding to home screen.

The devrels at both Google and Microsoft have been doing a great job of promoting progressive web apps. They’ve built tools to help you with tasks like generating icons or creating your web app manifest. It would be sooooo nifty if those tools also generated instructional screenshots for adding to home screen!

I don’t know about you, but it seems like everyone I follow on Twitter is playing Wordle. Although I don’t play the game myself, I think it’s pretty great.

Not only does Wordle have a very sweet backstory, but it’s also unashamedly on the web. If you want to play, you go to the URL powerlanguage.co.uk/wordle. That’s it. No need to download an app.

That hasn’t stopped some nefarious developers trying to trick people into downloading their clones of Wordle from app stores. App stores, which are meant to be curated and safe, are in fact filled with dodgy knock-offs and scams. Contrary to popular belief, the web is quite literally a safer bet.

Wordle has a web app manifest, which means you can add it to your home screen and it will behave just like a native app (although I don’t believe it has offline support). That’s great, but the process of adding a web app to your home screen on iOS is ludicrously long-winded.

Macworld published an article detailing how to get the real Wordle app on your iPhone or iPad. On the one hand it’s great to see this knowledge being spread. On the other hand it’s dispiriting that it’s even necessary to tell people that they can do this, like it’s a hidden nerdy secret just for power users.

At this point I’ve pretty much given up on Apple ever doing anything about this pathetic situation. So what can I do instead?

Well, taking my cue from that Macworld article, the least I can do is inform people how they can add a progressive web app to their home screen.

That’s what I’ve done on thesession.org. I’ve published a page on how to install The Session to your home screen.

On both Android and iPhone the journey to installing a progressive web app begins with incomprehensible iconography. On Android you must first tap on the unlabeled kebab icon—three vertical dots. On iOS you must first tap on the unlabeled share icon—a square with an arrow coming out of it.

When it comes to mobile operating systems, consumer choice means you choose which kind of mystery meat to eat.

I’ve included screenshots to help people identify these mysterious portals. For iOS I’ve also included a video to illustrate the quest to find the secret menu item buried beneath the share icon.

I’ve linked to the page with the installation instructions from the site’s “help” page and the home page.

Handy tip: when you’re adding a start_url value to your web app manifest, it’s common to include a query string like this:

start_url: "/?homescreen"

I’m guessing most people to that so they can get analytics on how many people are starting from an icon tap. I don’t do analytics on The Session but I’m still using that query string in my start_url. On the home page of the site, I check for the existence of the query string. If it exists, I don’t show the link to the installation page. So once someone has installed the site to their home screen, they shouldn’t see that message when they launch The Session.

If you’ve got a progressive web app, it might be worth making a page with installation instructions rather than relying on browsers to proactively inform your site’s visitors. You’d still need to figure out the right time and place to point people to that page, but at least the design challenge would be in your hands.

Should you decide to take a leaf out of the Android and iOS playbooks and use mystery meat navigation to link to such a page, there’s an emoji you could potentially use: 📲

It’s still worse than using actual words, but it might be better than some random combination of dots, squares and arrows.

(I’m not really serious about using that emoji, but if you do, be sure to use a sensible aria-label value on the enclosing a element.)

It’s said that the best way to learn about something is to teach it. I certainly found that to be true when I was writing the web.dev course on responsive design.

I felt fairly confident about some of the topics, but I felt somewhat out of my depth when it came to some of the newer modern additions to browsers. The last few modules in particular were unexplored areas for me, with topics like screen configurations and media features. I learned a lot about those topics by writing about them.

Best of all, I got to put my new-found knowledge to use! Here’s how…

The Session is a progressive web app. If you add it to the home screen of your mobile device, then when you launch the site by tapping on its icon, it behaves just like a native app.

In the web app manifest file for The Session, the display-mode property is set to “standalone.” That means it will launch without any browser chrome: no address bar and no back button. It’s up to me to provide the functionality that the browser usually takes care of.

So I added a back button in the navigation interface. It only appears on small screens.

Do you see the assumption I made?

I figured that the back button was most necessary in the situation where the site had been added to the home screen. That only happens on mobile devices, right?

Nope. If you’re using Chrome or Edge on a desktop device, you will be actively encourged to “install” The Session. If you do that, then just as on mobile, the site will behave like a standalone native app and launch without any browser chrome.

So desktop users who install the progressive web app don’t get any back button (because in my CSS I declare that the back button in the interface should only appear on small screens).

I was alerted to this issue on The Session:

It downloaded for me but there’s a bug, Jeremy - there doesn’t seem to be a way to go back.

Luckily, this happened as I was writing the module on media features. I knew exactly how to solve this problem because now I knew about the existence of the display-mode media feature. It allows you to write media queries that match the possible values of display-mode in a web app manifest:

.goback {
  display: none;
}
@media (display-mode: standalone) {
  .goback {
    display: inline;
  }
}

Now the back button shows up if you “install” The Session, regardless of whether that’s on mobile or desktop.

Previously I made the mistake of inferring whether or not to show the back button based on screen size. But the display-mode media feature allowed me to test the actual condition I cared about: is this user navigating in standalone mode?

If I hadn’t been writing about media features, I don’t think I would’ve been able to solve the problem. It’s a really good feeling when you’ve just learned something new, and then you immediately find exactly the right use case for it!

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.

I’m subscribed to a lot of blogs in my RSS reader. I follow some people because what they write about is very different to what I know about. But I also follow lots of people who have similar interests and ideas to me. So I’m not exactly in an echo chamber, but I do have the reverb turned up pretty high.

Sometimes these people post thoughts that are eerily similar to what I’ve been thinking about. Ethan has been known to do this. Get out of my head, Marcotte!

But even if Ethan wasn’t some sort of telepath, he’d still be in my RSS reader. We’re friends. Lots of the people in my RSS reader are my friends. When I read their words, I can hear their voices.

Then there are the people I’ve never met. Like Desirée García, Piper Haywood, or Jim Nielsen. Never met them, don’t know them, but damn, do I enjoy reading their blogs. Last year alone, I ended up linking to Jim’s posts ten different times.

Or Baldur Bjarnason. I can’t remember when I first came across his writing, but it really, really resonates with me. I probably owe him royalties for the amount of times I’ve cited his post Over-engineering is under-engineering.

His latest post is postively Marcottian in how it exposes what’s been fermenting in my own mind. But because he writes clearly, it really helps clarify my own thinking. It’s often been said that you should write to figure out what you think, and I can absolutely relate to that. But here’s a case where somebody else’s writing really helps to solidify my own thoughts.

Which type of novelty-seeking web developer are you?

It starts with some existentialist stock-taking. I can relate, what with the whole five decades thing. But then it turns the existential questioning to the World Wide Web itself, or rather, the people building the web.

In a way, it’s like taking the question of the great divide (front of the front end and back of the front end), and then turning it 45 degrees to reveal an entirely hidden dimension.

In examining the nature of the web, he hits on the litmus of how you view encapsulation:

I mention this first as it’s the aspect of the web that modern web developers hate the most without even giving it a label. Single-Page-Apps and GraphQL are both efforts to eradicate the encapsulation that’s baked into the foundation of every layer of the web.

Most modern devs are trying to get rid of it but it’s one of the web’s most strategic advantages.

I hadn’t thought of this before.

By default, if you don’t go against the grain of the web, each HTTP endpoint is encapsulated from each other.

Moreover, all of this can happen really fast if you aren’t going overboard with your CSS and JS.

He finishes with a look at another of the web’s most powerful features: distribution. In between are the things that make the web webby: hypertext and flexibility (The Dao of the Web).

It’s the idea that the web isn’t a single fixed thing but a fluid multitude whose shape is dictated by its surroundings.

This resonates with me because it highlights two different ways of viewing the web.

On the one hand, you can see the web purely as a distribution channel. In the past you might have been distributing a Flash movie. These days you might be distributing a single page app. Either way, the web is there as a low-friction way of getting your creation in front of other people.

The other way of building for the web is to go with the web’s grain, embracing flexibility and playing to the strengths of the medium through progressive enhancement. This is the distinction I was getting at when I talked about something being not just on the web, but of the web.

With that mindset, Baldur then takes us through some of the technologies that he’s excited about, like SvelteKit and Hotwire. I think it’s the same mindset that got me excited about service workers. As Baldur says:

They are helping the web become better at being its own thing.

That’s my tagline right there.

I’ve been thinking some more about the technical experience of booking a vaccination apointment and how much joy it brought me.

I’ve written before about how I’ve got a blind spot for the web so it’s no surprise that I was praising the use of a well marked-up form, styled clearly, and unencumbered by unnecessary JavaScript. But other technologies were in play too: Short Message Service (SMS) and email.

All of those technologies are platform-agnostic.

No matter what operating system I’m using, or what email software I’ve chosen, email works. It gets more complicated when you introduce HTML email. My response to that is the same as the old joke; you know the one: “Doctor, it hurts when I do this.” (“Well, don’t do that.”)

No matter what operating system my phone is using, SMS works. It gets more complicated when you introduce read receipts, memoji, or other additions. See my response to HTML email.

Then there’s the web. No matter what operating system I’m using on a device that could be a phone or a tablet or a laptop or desktop tower, and no matter what browser I’ve chosen to use, the World Wide Web works.

I originally said:

It feels like the principle of least power in action.

But another way of rephrasing “least power” is “most availability.” Technologies that are old, simple, and boring tend to be more widely available.

I remember when software used to come packaged in boxes and displayed on shelves. The packaging always had a list on the side. It looked like the nutritional information on a food product, but this was a list of “system requirements”: operating system, graphics card, sound card, CPU. I never liked the idea of system requirements. It felt so …exclusionary. And for me, the promise of technology was liberation and freedom to act on my own terms.

Hence my soft spot for the boring and basic technologies like email, SMS, and yes, web pages. The difference with web pages is that you can choose to layer added extras on top. As long as the fundamental functionality is using universally-supported technology, you’re free to enhance with all the latest CSS and JavaScript. If any of it fails, that’s okay: it falls back to a nice solid base.

Alas, many developers don’t build with this mindset. I mean, I understand why: it means thinking about users with the most boring, least powerful technology. It’s simpler and more exciting to assume that everyone’s got a shared baseline of newer technology. But by doing that, you’re missing out on one of the web’s superpowers: that something served up at the same URL with the same underlying code can simultaneously serve people with older technology and also provide a whizz-bang experience to people with the latest and greatest technology.

Anyway, I’ve been thinking about the kind of communication technologies that are as universal as email, SMS, and the web.

QR codes are kind of heading in that direction, although I still have qualms because of their proprietary history. But there’s something nice and lo-fi about them. They’re like print stylesheets in reverse (and I love print stylesheets). A funky little bridge between the physical and the digital. I just wish they weren’t so opaque: you never know if scanning that QR code will actually take you to the promised resource, or if you’re about to rickroll yourself.

Telephone numbers kind of fall into the same category as SMS, but with the added option of voice. I’ve always found the prospect of doing something with, say, Twilio’s API more interesting than building something inside a walled garden like Facebook Messenger or Alexa.

I know very little about chat apps or voice apps, but I don’t think there’s a cross-platform format that works with different products, right? I imagine it’s like the situation with native apps which require a different codebase for each app store and operating system. And so there’s a constant stream of technologies that try to fulfil the dream of writing once and running everywhere: React Native, Flutter.

They’re trying to solve a very clear and obvious problem: writing the same app more than once is really wasteful. But that’s the nature of the game when it comes to runtime-specific apps. The only alternative is to either deliberately limit your audience …or apply the principle of least power/most availability.

The wastefulness of having to write the same app for multiple platforms isn’t the only thing that puts me off making native apps. The exclusivity works in two directions. There’s the exclusive nature of the runtime that requires a bespoke codebase. There’s also the exclusive nature of the app store. It feels like a return to shelves of packaged software with strict system requirements. You can’t just walk in and put your software on the shelf. That’s the shopkeeper’s job.

There is no shopkeeper for the World Wide Web.

I started getting some emails recently from people having issues using The Session. The issues sounded similar—an interactive component that wasn’t, well …interacting.

When I asked what device or browser they were using, the answer came back the same: Safari on iPad. But not a new iPad. These were older iPads running older operating systems.

Now, remember, even if I wanted to recommend that they use a different browser, that’s not an option:

Safari is the only browser on iOS devices.

I don’t mean it’s the only browser that ships with iOS devices. I mean it’s the only browser that can be installed on iOS devices.

You can install something called Chrome. You can install something called Firefox. Those aren’t different web browsers. Under the hood they’re using Safari’s rendering engine. They have to.

It gets worse. Not only is there no choice when it comes to rendering engines on iOS, but the rendering engine is also tied to the operating system.

If you’re on an old Apple laptop, you can at least install an up-to-date version of Firefox or Chrome. But you can’t install an up-to-date version of Safari. An up-to-date version of Safari requires an up-to-date version of the operating system.

It’s the same on iOS devices—you can’t install a newer version of Safari without installing a newer version of iOS. But unlike the laptop scenario, you can’t install any version of Firefox of Chrome.

It’s disgraceful.

It’s particularly frustrating when an older device can’t upgrade its operating system. Upgrades for Operating system generally have some hardware requirements. If your device doesn’t meet those requirements, you can’t upgrade your operating system. That wouldn’t matter so much except for the Safari issue. Without an upgraded operating system, your web browsing experience stagnates unnecessarily.

For want of a nail…

• A website feature isn’t working so
• you need to upgrade your browser which means
• you need to upgrade your operating sytem but
• you can’t upgrade your operating system so
• you need to buy a new device.

Apple doesn’t allow other browsers to be installed on iOS devices so people have to buy new devices if they want to use the web. Handy for Apple. Bad for users. Really bad for the planet.

It’s particularly galling when it comes to iPads. Those are exactly the kind of casual-use devices that shouldn’t need to be caught in the wasteful cycle of being used for a while before getting thrown away. I mean, I get why you might want to have a relatively modern phone—a device that’s constantly with you that you use all the time—but an iPad is the perfect device to just have lying around. You shouldn’t feel pressured to have the latest model if the older version still does the job:

An older tablet makes a great tableside companion in your living room, an effective e-book reader, or a light-duty device for reading mail or checking your favorite websites.

Hang on, though. There’s another angle to this. Why should a website demand an up-to-date browser? If the website has been built using the tried and tested approach of progressive enhancement, then everyone should be able to achieve their goals regardless of what browser or device or operating system they’re using.

On The Session, I’m using progressive enhancement and feature detection everywhere I can. If, for example, I’ve got some JavaScript that’s going to use querySelectorAll and addEventListener, I’ll first test that those methods are available.

if (!document.querySelectorAll || !window.addEventListener) {
  // doesn't cut the mustard.
  return;
}

I try not to assume that anything is supported. So why was I getting emails from people with older iPads describing an interaction that wasn’t working? A JavaScript error was being thrown somewhere and—because of JavaScript’s brittle error-handling—that was causing all the subsequent JavaScript to fail.

I tracked the problem down to a function that was using some DOM methods—matches and closest—as well as the relatively recent JavaScript forEach method. But I had polyfills in place for all of those. Here’s the polyfill I’m using for matches and closest. And here’s the polyfill I’m using for forEach.

Then I spotted the problem. I was using forEach to loop through the results of querySelectorAll. But the polyfill works on arrays. Technically, the output of querySelectorAll isn’t an array. It looks like an array, it quacks like an array, but it’s actually a node list.

So I added this polyfill from Chris Ferdinandi.

That did the trick. I checked with the people with those older iPads and everything is now working just fine.

For the record, here’s the small collection of polyfills I’m using. Polyfills are supposed to be temporary. At some stage, as everyone upgrades their browsers, I should be able to remove them. But as long as some people are stuck with using an older browser, I have to keep those polyfills around.

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.

Apple may argue that their browser rendering engine and their operating system are deeply intertwingled. That line of defence worked out great for Microsoft in the ‘90s.

Vendor prefixes didn’t work. The theory was sound. It was a way of marking CSS and JavaScript features as being experimental. Developers could use the prefixed properties as long as they understood that those features weren’t to be relied upon.

That’s not what happened though. Developers used vendor-prefixed properties as though they were stable. Tutorials were published that basically said “Go ahead and use these vendor-prefixed properties and ship it!” There were even tools that would add the prefixes for you so you didn’t have to type them out for yourself.

Browsers weren’t completely blameless either. Long after features were standardised, they would only be supported in their prefixed form. Apple was and is the worst for this. To this day, if you want to use the clip-path property in your CSS, you’ll need to duplicate your declaration with -webkit-clip-path if you want to support Safari. It’s been like that for seven years and counting.

Like capitalism, vendor prefixes were one of those ideas that sounded great in theory but ended up being unworkable in practice.

Still, developers need some way to get their hands on experiment features. But we don’t want browsers to ship experimental features without some kind of safety mechanism.

The current thinking involves something called origin trials. Here’s the explainer from Microsoft Edge and here’s Google Chrome’s explainer:

• Developers are able to register for an experimental feature to be enabled on their origin for a fixed period of time measured in months. In exchange, they provide us their email address and agree to give feedback once the experiment ends.
• Usage of these experiments is constrained to remain below Chrome’s deprecation threshold (< 0.5% of all Chrome page loads) by a system which automatically disables the experiment on all origins if this threshold is exceeded.

I think it works pretty well. If you’re really interested in kicking the tyres on an experimental feature, you can opt in to the origin trial. But it’s very clear that you wouldn’t want to ship it to production.

That said…

You could ship something that’s behind an origin trial, but you’d have to make sure you’re putting safeguards in place. At the very least, you’d need to do feature detection. You certainly couldn’t use an experimental feature for anything mission critical …but you could use it as an enhancement.

And that is a pretty great way to think about all web features, experimental or otherwise. Don’t assume the feature will be supported. Use feature detection (or @supports in the case of CSS). Try to use the feature as an enhancement rather than a dependency.

If you treat all browser features as though they’re behind an origin trial, then suddenly the landscape of browser support becomes more navigable. Instead of looking at the support table for something on caniuse.com and thinking, “I wish more browsers supported this feature so that I could use it!”, you can instead think “I’m going to use this feature today, but treat it as an experimental feature.”

You can also do it for well-established features like querySelector, addEventListener, and geolocation. Instead of assuming that browser support is universal, it doesn’t hurt to take a more defensive approach. Assume nothing. Acknowledge and embrace unpredictability.

The debacle with vendor prefixes shows what happens if we treat experimental features as though they’re stable. So let’s flip that around. Let’s treat stable features as though they’re experimental. If you cultivate that mindset, your websites will be more robust and resilient.

I added a long-overdue enhancement to The Session recently. Here’s the scenario…

You’re on a web page with a comment form. You type your well-considered thoughts into a textarea field. But then something happens. Maybe you accidentally navigate away from the page or maybe your network connection goes down right when you try to submit the form.

This is a textbook case for storing data locally on the user’s device …at least until it has safely been transmitted to the server. So that’s what I set about doing.

My first decision was choosing how to store the data locally. There are multiple APIs available: sessionStorage, IndexedDB, localStorage. It was clear that sessionStorage wasn’t right for this particular use case: I needed the data to be saved across browser sessions. So it was down to IndexedDB or localStorage. IndexedDB is the more versatile and powerful—because it’s asynchronous—but localStorage is nice and straightforward so I decided on that. I’m not sure if that was the right decision though.

Alright, so I’m going to store the contents of a form in localStorage. It accepts key/value pairs. I’ll make the key the current URL. The value will be the contents of that textarea. I can store other form fields too. Even though localStorage technically only stores one value, that value can be a JSON object so in reality you can store multiple values with one key (just remember to parse the JSON when you retrieve it).

Now I know what I’m going to store (the textarea contents) and how I’m going to store it (localStorage). The next question is when should I do it?

I could play it safe and store the comment whenever the user presses a key within the textarea. But that seems like overkill. It would be more efficient to only save when the user leaves the current page for any reason.

Alright then, I’ll use the unload event. No! Bad Jeremy! If I use that then the browser can’t reliably add the current page to the cache it uses for faster back-forwards navigations. The page life cycle is complicated.

So beforeunload then? Well, maybe. But modern browsers also support a pagehide event that looks like a better option.

In either case, just adding a listener for the event could screw up the caching of the page for back-forwards navigations. I should only listen for the event if I know that I need to store the contents of the textarea. And in order to know if the user has interacted with the textarea, I’m back to listening for key presses again.

But wait a minute! I don’t have to listen for every key press. If the user has typed anything, that’s enough for me. I only need to listen for the first key press in the textarea.

Handily, addEventListener accepts an object of options. One of those options is called “once”. If I set that to true, then the event listener is only fired once.

So I set up a cascade of event listeners. If the user types anything into the textarea, that fires an event listener (just once) that then adds the event listener for when the page is unloaded—and that’s when the textarea contents are put into localStorage.

I’ve abstracted my code into a gist. Here’s what it does:

1. Cut the mustard. If this browser doesn’t support localStorage, bail out.
2. Set the localStorage key to be the current URL.
3. If there’s already an entry for the current URL, update the textarea with the value in localStorage.
4. Write a function to store the contents of the textarea in localStorage but don’t call the function yet.
5. The first time that a key is pressed inside the textarea, start listening for the page being unloaded.
6. When the page is being unloaded, invoke that function that stores the contents of the textarea in localStorage.
7. When the form is submitted, remove the entry in localStorage for the current URL.

That last step isn’t something I’m doing on The Session. Instead I’m relying on getting something back from the server to indicate that the form was successfully submitted. If you can do something like that, I’d recommend that instead of listening to the form submission event. After all, something could still go wrong between the form being submitted and the data being received by the server.

Still, this bit of code is better than nothing. Remember, it’s intended as an enhancement. You should be able to drop it into any project and improve the user experience a little bit. Ideally, no one will ever notice it’s there—it’s the kind of enhancement that only kicks in when something goes wrong. A little smidgen of resilient web design. A defensive enhancement.

I’m a big fan of HTML5’s datalist element and its elegant design. It’s a way to progressively enhance any input element into a combobox.

You use the list attribute on the input element to point to the ID of the associated datalist element.

<label for="homeworld">Your home planet</label>
<input type="text" name="homeworld" id="homeworld" list="planets">
<datalist id="planets">
 <option value="Mercury">
 <option value="Venus">
 <option value="Earth">
 <option value="Mars">
 <option value="Jupiter">
 <option value="Saturn">
 <option value="Uranus">
 <option value="Neptune">
</datalist>

It even works on input type="color", which is pretty cool!

The most common use case is as an autocomplete widget. That’s how I’m using it over on The Session, where the datalist is updated via Ajax every time the input is updated.

But let’s stick with a simple example, like the list of planets above. Suppose the user types “jup” …the datalist will show “Jupiter” as an option. The user can click on that option to automatically complete their input.

It would be handy if you could automatically submit the form when the user chooses a datalist option like this.

Well, tough luck.

The datalist element emits no events. There’s no way of telling if it has been clicked. This is something I’ve been trying to find a workaround for.

I got my hopes up when I read Amber’s excellent article about document.activeElement. But no, the focus stays on the input when the user clicks on an option in a datalist.

So if I can’t detect whether a datalist has been used, this best I can do is try to infer it. I know it’s not exactly the same thing, and it won’t be as reliable as true detection, but here’s my logic:

• Keep track of the character count in the input element.
• Every time the input is updated in any way, check the current character count against the last character count.
• If the difference is greater than one, something interesting happened! Maybe the user pasted a value in …or maybe they used the datalist.
• Loop through each of the options in the datalist.
• If there’s an exact match with the current value of the input element, chances are the user chose that option from the datalist.
• So submit the form!

Here’s how that translates into DOM scripting code:

document.querySelectorAll('input[list]').forEach( function (formfield) {
  var datalist = document.getElementById(formfield.getAttribute('list'));
  var lastlength = formfield.value.length;
  var checkInputValue = function (inputValue) {
    if (inputValue.length - lastlength > 1) {
      datalist.querySelectorAll('option').forEach( function (item) {
        if (item.value === inputValue) {
          formfield.form.submit();
        }
      });
    }
    lastlength = inputValue.length;
  };
  formfield.addEventListener('input', function () {
    checkInputValue(this.value);
  }, false);
});

I’ve made a gist with some added feature detection and mustard-cutting at the start. You should be able to drop it into just about any page that’s using datalist. It works even if the options in the datalist are dynamically updated, like the example on The Session.

It’s not foolproof. The inference relies on the difference between what was previously typed and what’s autocompleted to be more than one character. So in the planets example, if someone has type “Jupite” and then they choose “Jupiter” from the datalist, the form won’t automatically submit.

But still, I reckon it covers most common use cases. And like the datalist element itself, you can consider this functionality a progressive enhancement.

Progressive enhancement is at the heart of everything I do on the web. It’s the bedrock of my speaking and writing too. Whether I’m writing about JavaScript, Ajax, HTML, or service workers, it’s always through the lens of progressive enhancement. Sometimes I explicitly bang the drum, like with Resilient Web Design. Other times I don’t mention it by name at all, and instead talk only about its benefits.

I sometimes get asked to name some examples of sites that still offer their core functionality even when JavaScript fails. I usually mention Amazon.com, although that has other issues. But quite often I find that a lot of the examples I might mention are dismissed as not being “web apps” (whatever that means).

The pushback I get usually takes the form of “Well, that approach is fine for websites, but it wouldn’t work something like Gmail.”

It’s always Gmail. Which is odd. Because if you really wanted to flummox me with a product or service that defies progressive enhancement, I’d have a hard time with something like, say, a game (although it would be pretty cool to build a text adventure that’s progressively enhanced into a first-person shooter). But an email client? That would work.

Identify core functionality.

Read emails. Write emails.

Make that functionality available using the simplest possible technology.

HTML for showing a list of emails, HTML for displaying the contents of the HTML, HTML for the form you write the response in.

Enhance!

Now add all the enhancements that improve the experience—keyboard shortcuts; Ajax instead of full-page refreshes; local storage, all that stuff.

Can you build something that works just like Gmail without using any JavaScript? No. But that’s not what progressive enhancement is about. It’s about providing the core functionality (reading and writing emails) with the simplest possible technology (HTML) and then enhancing using more powerful technologies (like JavaScript).

Progressive enhancement isn’t about making a choice between using simpler more robust technologies or using more advanced features; it’s about using simpler more robust technologies and then using more advanced features. Have your cake and eat it.

Fortunately I no longer need to run this thought experiment to imagine what it would be like if something like Gmail were built with a progressive enhancement approach. That’s what HEY is.

Sam Stephenson describes the approach they took:

HEY’s UI is 100% HTML over the wire. We render plain-old HTML pages on the server and send them to your browser encoded as text/html. No JSON APIs, no GraphQL, no React—just form submissions and links.

If you think that sounds like the web of 25 years ago, you’re right! Except the HEY front-end stack progressively enhances the “classic web” to work like the “2020 web,” with all the fidelity you’d expect from a well-built SPA.

See? It’s not either resilient or modern—it’s resilient and modern. Have your cake and eat it.

And yet this supremely sensible approach is not considered “modern” web development:

The architecture astronauts who, for the past decade, have been selling us on the necessity of React, Redux, and megabytes of JS, cannot comprehend the possibility of building an email app in 2020 with server-rendered HTML.

HEY isn’t perfect by any means—they’ve got a lot of work to do on their accessibility. But it’s good to have a nice short answer to the question “But what about something like Gmail?”

It reminds me of responsive web design:

When Ethan Marcotte demonstrated the power of responsive design, it was met with resistance. “Sure, a responsive design might work for a simple personal site but there’s no way it could scale to a large complex project.”

Then the Boston Globe launched its responsive site. Microsoft made their homepage responsive. The floodgates opened again.

It’s a similar story today. “Sure, progressive enhancement might work for a simple personal site, but there’s no way it could scale to a large complex project.”

The floodgates are ready to open. We just need you to create the poster child for resilient web design.

It looks like HEY might be that poster child.

I have to wonder if its coincidence or connected that this is a service that’s also tackling ethical issues like tracking? Their focus is very much on people above technology. They’ve taken a human-centric approach to their product and a human-centric approach to web development …because ultimately, that’s what progressive enhancement is.

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 Sli.do. 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:

https://adactio.com/journal/16099

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!

https://adactio.com/journal/14803

https://adactio.com/journal/14821

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:

https://adactio.com/journal/16619

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:

https://adactio.com/journal/9195

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