Tags: form



Saturday, December 26th, 2020

How Claude Shannon’s Information Theory Invented the Future | Quanta Magazine

Shannon is not exactly a household name. He never won a Nobel Prize, and he wasn’t a celebrity like Albert Einstein or Richard Feynman, either before or after his death in 2001. But more than 70 years ago, in a single groundbreaking paper, he laid the foundation for the entire communication infrastructure underlying the modern information age.

Wednesday, December 23rd, 2020

HTML Over The Wire | Hotwire

This is great! The folks at Basecamp are releasing the front-end frameworks they use to build Hey. There’s Turbo—the successor to Turbolinks:

It offers a simpler alternative to the prevailing client-side frameworks which put all the logic in the front-end and confine the server side of your app to being little more than a JSON API.

With Turbo, you let the server deliver HTML directly, which means all the logic for checking permissions, interacting directly with your domain model, and everything else that goes into programming an application can happen more or less exclusively within your favorite programming language. You’re no longer mirroring logic on both sides of a JSON divide. All the logic lives on the server, and the browser deals just with the final HTML.

Yes, this is basically Hijax (which is itself simply a name for progressive enhancement applied to Ajax) and I’m totally fine with that. I don’t care what it’s called when the end result is faster, more resilient websites.

Compare and contrast the simplicity of the Hotwire/Turbo approach to the knots that React is tying itself up in to try to get the same performance benefits.

Tuesday, December 22nd, 2020

Ignore AMP · Jens Oliver Meiert

It started using the magic spell of prominent results page display to get authors to use it. Nothing is left of the original lure of raising awareness for web performance, and nothing convincing is there to confirm it was, indeed, a usable “web component framework.”

Friday, December 18th, 2020

Conditional JavaScript - JavaScript - Dev Tips

This is a good round-up of APIs you can use to decide if and how much JavaScript to load. I might look into using storage.estimate() in service workers to figure out how much gets pre-cached.

Wednesday, December 16th, 2020


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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Tuesday, December 15th, 2020


I was very inspired by something Terence Eden wrote on his blog last year. A report from the AMP Advisory Committee Meeting:

I don’t like AMP. I think that Google’s Accelerated Mobile Pages are a bad idea, poorly executed, and almost-certainly anti-competitive.

So, I decided to join the AC (Advisory Committee) for AMP.

Like Terence, I’m not a fan of Google AMP—my initially positive reaction to it soured over time as it became clear that Google were blackmailing publishers by privileging AMP pages in Google Search. But all I ever did was bitch and moan about it on my website. Terence actually did something.

So this year I put myself forward as a candidate for the AMP advisory committee. I have no idea how the election process works (or who does the voting) but thanks to whoever voted for me. I’m now a member of the AMP advisory committee. If you look at that blog post announcing the election results, you’ll see the brief blurb from everyone who was voted in. Most of them are positively bullish on AMP. Mine is not:

Jeremy Keith is a writer and web developer dedicated to an open web. He is concerned that AMP is being unfairly privileged by Google’s search engine instead of competing on its own merits.

The good news is that main beef with AMP is already being dealt with. I wanted exactly what Terence said:

My recommendation is that Google stop requiring that organisations use Google’s proprietary mark-up in order to benefit from Google’s promotion.

That’s happening as of May of this year. Just as well—the AMP advisory committee have absolutely zero influence on Google search. I’m not sure how much influence we have at all really.

This is an interesting time for AMP …whatever AMP is.

See, that’s been a problem with Google AMP from the start. There are multiple defintions of what AMP is. At the outset, it seemed pretty straightforward. AMP is a format. It has a doctype and rules that you have to meet in order to be “valid” AMP. Part of that ruleset involved eschewing HTML elements like img and video in favour of web components like amp-img and amp-video.

That messaging changed over time. We were told that AMP is the collection of web components. If that’s the case, then I have no problem at all with AMP. People are free to use the components or not. And if the project produces performant accessible web components, then that’s great!

But right now it’s not at all clear which AMP people are talking about, even in the advisory committee. When we discuss improving AMP, do we mean the individual components or the set of rules that qualify an AMP page being “valid”?

The use-case for AMP-the-format (as opposed to AMP-the-library-of-components) was pretty clear. If you were a publisher and you wanted to appear in the top stories carousel in Google search, you had to publish using AMP. Just using the components wasn’t enough. Your pages had to be validated as AMP-the-format.

That’s no longer the case. From May, pages that are fast enough will qualify for the top stories carousel. What will publishers do then? Will they still maintain separate AMP-the-format pages? Time will tell.

I suspect publishers will ditch AMP-the-format, although it probably won’t happen overnight. I don’t think anyone likes being blackmailed by a search engine:

An engineer at a major news publication who asked not to be named because the publisher had not authorized an interview said Google’s size is what led publishers to use AMP.

The pre-rendering (along with the lightning bolt) that happens for AMP pages in Google search might be a reason for publishers to maintain their separate AMP-the-format pages. But I suspect publishers don’t actually think the benefits of pre-rendering outweigh the costs: pre-rendered AMP-the-format pages are served from Google’s servers with a Google URL. If anything, I think that publishers will look forward to having the best of both worlds—having their pages appear in the top stories carousel, but not having their pages hijacked by Google’s so-called-cache.

Does AMP-the-format even have a future without Google search propping it up? I hope not. I think it would make everything much clearer if AMP-the-format went away, leaving AMP-the-collection-of-components. We’d finally see these components being evaluated on their own merits—usefulness, performance, accessibility—without unfair interference.

So my role on the advisory committee so far has been to push for clarification on what we’re supposed to be advising on.

I think it’s good that I’m on the advisory committee, although I imagine my opinions could easily be be dismissed given my public record of dissent. I may well be fooling myself though, like those people who go to work at Facebook and try to justify it by saying they can accomplish more from inside than outside (or whatever else they tell themselves to sleep at night).

The topic I’ve volunteered to help with is somewhat existential in nature: what even is AMP? I’m happy to spend some time on that. I think it’ll be good for everyone to try to get that sorted, regardless about how you feel about the AMP project.

I have no intention of giving any of my unpaid labour towards the actual components themselves. I know AMP is theoretically open source now, but let’s face it, it’ll always be perceived as a Google-led project so Google can pay people to work on it.

That said, I’ve also recently joined a web components community group that Lea instigated. Remember she wrote that great blog post recently about the failed promise of web components? I’m not sure how much I can contribute to the group (maybe some meta-advice on the nature of good design principles?) but at the very least I can serve as a bridge between the community group and the AMP advisory committee.

After all, AMP is a collection of web components. Maybe.

Cascading Style Sheets

There are three ways—that I know of—to associate styles with markup.

External CSS

This is probably the most common. Using a link element with a rel value of “stylesheet”, you point to a URL using the href attribute. That URL is a style sheet that is applied to the current document (“the relationship of the linked resource it is that is a ‘stylesheet’ for the current document”).

<link rel="stylesheet" href="/path/to/styles.css">

In theory you could associate a style sheet with a document using an HTTP header, but I don’t think many browsers support this in practice.

You can also pull in external style sheets using the @import declaration in CSS itself, as long as the @import rule is declared at the start, before any other styles.

@import url('/path/to/more-styles.css');

When you use link rel="stylesheet" to apply styles, it’s a blocking request: the browser will fetch the style sheet before rendering the HTML. It needs to know how the HTML elements will be painted to the screen so there’s no point rendering the HTML until the CSS is parsed.

Embedded CSS

You can also place CSS rules inside a style element directly in the document. This is usually in the head of the document.

element {
    property: value;

When you embed CSS in the head of a document like this, there is no network request like there would be with external style sheets so there’s no render-blocking behaviour.

You can put any CSS inside the style element, which means that you could use embedded CSS to load external CSS using an @import statement (as long as that @import statement appears right at the start).

@import url('/path/to/more-styles.css');
element {
    property: value;

But then you’re back to having a network request.

Inline CSS

Using the style attribute you can apply CSS rules directly to an element. This is a universal attribute. It can be used on any HTML element. That doesn’t necessarily mean that the styles will work, but your markup is never invalidated by the presence of the style attribute.

<element style="property: value">

Whereas external CSS and embedded CSS don’t have any effect on specificity, inline styles are positively radioactive with specificity. Any styles applied this way are almost certain to over-ride any external or embedded styles.

You can also apply styles using JavaScript and the Document Object Model.

element.style.property = 'value';

Using the DOM style object this way is equivalent to inline styles. The radioactive specificity applies here too.

Style declarations specified in external style sheets or embedded CSS follow the rules of the cascade. Values can be over-ridden depending on the order they appear in. Combined with the separate-but-related rules for specificity, this can be very powerful. But if you don’t understand how the cascade and specificity work then the results can be unexpected, leading to frustration. In that situation, inline styles look very appealing—there’s no cascade and everything has equal specificity. But using inline styles means foregoing a lot of power—you’d be ditching the C in CSS.

A common technique for web performance is to favour embedded CSS over external CSS in order to avoid the extra network request (at least for the first visit—there are clever techniques for caching an external style sheet once the HTML has already loaded). This is commonly referred to as inlining your CSS. But really it should be called embedding your CSS.

This language mix-up is not a hill I’m going to die on (that hill would be referring to blog posts as blogs) but I thought it was worth pointing out.

Monday, December 14th, 2020

Web Almanac 2020

I spent most of the weekend reading through this and I’ve still barely scratched the surface—a lot of work has gone to the analyses and write-ups!

The sections on accessibility and performance get grimmer each year but the raw numbers on framework adaption are refreshingly perspective-setting.

Monday, November 30th, 2020

Clean advertising

Imagine if you were told that fossil fuels were the only way of extracting energy. It would be an absurd claim. Not only are other energy sources available—solar, wind, geothermal, nuclear—fossil fuels aren’t even the most effecient source of energy. To say that you can’t have energy without burning fossil fuels would be pitifully incorrect.

And yet when it comes to online advertising, we seem to have meekly accepted that you can’t have effective advertising without invasive tracking. But nothing could be further from the truth. Invasive tracking is to online advertising as fossil fuels are to energy production—an outmoded inefficient means of getting substandard results.

Before the onslaught of third party cookies and scripts, online advertising was contextual. If I searched for property insurance, I was likely to see an advertisement for property insurance. If I was reading an article about pet food, I was likely to be served an advertisement for pet food.

Simply put, contextual advertising ensured that the advertising that accompanied content could be relevant and timely. There was no big mystery about it: advertisers just needed to know what the content was about and they could serve up the appropriate advertisement. Nice and straightforward.

Too straightforward.

What if, instead of matching the advertisement to the content, we could match the advertisement to the person? Regardless of what they were searching for or reading, they’d be served advertisements that were relevant to them not just in that moment, but relevant to their lifestyles, thoughts and beliefs? Of course that would require building up dossiers of information about each person so that their profiles could be targeted and constantly updated. That’s where cross-site tracking comes in, with third-party cookies and scripts.

This is behavioural advertising. It has all but elimated contextual advertising. It has become so pervasive that online advertising and behavioural advertising have become synonymous. Contextual advertising is seen as laughably primitive compared with the clairvoyant powers of behavioural advertising.

But there’s a problem with behavioural advertising. A big problem.

It doesn’t work.

First of all, it relies on mind-reading powers by the advertising brokers—Facebook, Google, and the other middlemen of ad tech. For all the apocryphal folk tales of spooky second-guessing in online advertising, it mostly remains rubbish.

Forget privacy: you’re terrible at targeting anyway:

None of this works. They are still trying to sell me car insurance for my subway ride.

Have you actually paid attention to what advertisements you’re served? Maciej did:

I saw a lot of ads for GEICO, a brand of car insurance that I already own.

I saw multiple ads for Red Lobster, a seafood restaurant chain in America. Red Lobster doesn’t have any branches in San Francisco, where I live.

Finally, I saw a ton of ads for Zipcar, which is a car sharing service. These really pissed me off, not because I have a problem with Zipcar, but because they showed me the algorithm wasn’t even trying. It’s one thing to get the targeting wrong, but the ad engine can’t even decide if I have a car or not! You just showed me five ads for car insurance.

And yet in the twisted logic of ad tech, all of this would be seen as evidence that they need to gather even more data with even more invasive tracking and surveillance.

It turns out that bizarre logic is at the very heart of behavioural advertising. I highly recommend reading the in-depth report from The Correspondent called The new dot com bubble is here: it’s called online advertising:

It’s about a market of a quarter of a trillion dollars governed by irrationality.

The benchmarks that advertising companies use – intended to measure the number of clicks, sales and downloads that occur after an ad is viewed – are fundamentally misleading. None of these benchmarks distinguish between the selection effect (clicks, purchases and downloads that are happening anyway) and the advertising effect (clicks, purchases and downloads that would not have happened without ads).

Suppose someone told you that they keep tigers out of their garden by turning on their kitchen light every evening. You might think their logic is flawed, but they’ve been turning on the kitchen light every evening for years and there hasn’t been a single tiger in the garden the whole time. That’s the logic used by ad tech companies to justify trackers.

Tracker-driven behavioural advertising is bad for users. The advertisements are irrelevant most of the time, and on the few occasions where the advertising hits the mark, it just feels creepy.

Tracker-driven behavioural advertising is bad for advertisers. They spend their hard-earned money on invasive ad tech that results in no more sales or brand recognition than if they had relied on good ol’ contextual advertising.

Tracker-driven behavioural advertising is very bad for the web. Megabytes of third-party JavaScript are injected at exactly the wrong moment to make for the worst possible performance. And if that doesn’t ruin the user experience enough, there are still invasive overlays and consent forms to click through (which, ironically, gets people mad at the legislation—like GDPR—instead of the underlying reason for these annoying overlays: unnecessary surveillance and tracking by the site you’re visiting).

Tracker-driven behavioural advertising is good for the middlemen doing the tracking. Facebook and Google are two of the biggest players here. But that doesn’t mean that their business models need to be permanently anchored to surveillance. The very monopolies that make them kings of behavioural advertising—the biggest social network and the biggest search engine—would also make them titans of contextual advertising. They could pivot from an invasive behavioural model of advertising to a privacy-respecting contextual advertising model.

The incumbents will almost certainly resist changing something so fundamental. It would be like expecting an energy company to change their focus from fossil fuels to renewables. It won’t happen quickly. But I think that it may eventually happen …if we demand it.

In the meantime, we can all play our part. Just as we can do our bit for the environment at an individual level by sorting our recycling and making green choices in our day to day lives, we can all do our bit for the web too.

The least we can do is block third-party cookies. Some browsers are now doing this by default. That’s good.

Blocking third-party JavaScript is a bit trickier. That requires a browser extension. Most of these extensions to block third-party tracking are called ad blockers. That’s a shame. The issue is not with advertising. The issue is with tracking.

Alas, because this software is labelled under ad blocking, it has led to the ludicrous situation of an ethical argument being made to allow surveillance and tracking! It goes like this: websites need advertising to survive; if you block the ads, then you are denying these sites revenue. That argument would make sense if we were talking about contextual advertising. But it makes no sense when it comes to behavioural advertising …unless you genuinely believe that online advertising has to be behavioural, which means that online advertising has to track you to be effective. Such a belief would be completely wrong. But that doesn’t stop it being widely held.

To argue that there is a moral argument against blocking trackers is ridiculous. If anything, there’s a moral argument to be made for installing anti-tracking software for yourself, your friends, and your family. Otherwise we are collectively giving up our privacy for a business model that doesn’t even work.

It’s a shame that advertisers will lose out if tracking-blocking software prevents their ads from loading. But that’s only going to happen in the case of behavioural advertising. Contextual advertising won’t be blocked. Contextual advertising is also more lightweight than behavioural advertising. Contextual advertising is far less creepy than behavioural advertising. And crucially, contextual advertising works.

That shouldn’t be a controversial claim: the idea that people would be interested in adverts that are related to the content they’re currently looking at. The greatest trick the ad tech industry has pulled is convincing the world that contextual relevance is somehow less effective than some secret algorithm fed with all our data that’s supposed to be able to practically read our minds and know us better than we know ourselves.

Y’know, if this mind-control ray really could give me timely relevant adverts, I might possibly consider paying the price with my privacy. But as it is, YouTube still hasn’t figured out that I’m not interested in Top Gear or football.

The next time someone is talking about the necessity of advertising on the web as a business model, ask for details. Do they mean contextual or behavioural advertising? They’ll probably laugh at you and say that behavioural advertising is the only thing that works. They’ll be wrong.

I know it’s hard to imagine a future without tracker-driven behavioural advertising. But there are no good business reasons for it to continue. It was once hard to imagine a future without oil or coal. But through collective action, legislation, and smart business decisions, we can make a cleaner future.

Thursday, November 19th, 2020

Standardizing `select` And Beyond: The Past, Present And Future Of Native HTML Form Controls — Smashing Magazine

While a handful of form controls can be easily styled by CSS, like the button element, most form controls fall into a bucket of either requiring hacky CSS or are still unable to be styled at all by CSS.

Despite form controls no longer taking a style or technical dependency on the operating system and using modern rendering technology from the browser, developers are still unable to style some of the most used form control elements such as select. The root of this problem lies in the way the specification was originally written for form controls back in 1995.

Stephanie goes back in time to tell the history of form controls on the web, and how that history has led to our current frustrations:

The current state of working with controls on the modern web is that countless developer hours are being lost to rewriting controls from scratch, as custom elements due to a lack of flexibility in customizability and extensibility of native form controls. This is a massive gap in the web platform and has been for years. Finally, something is being done about it.


Monday, November 16th, 2020

The Core Web Vitals hype train

Goodhart’s Law applied to Google’s core web vitals:

If developers start to focus solely on Core Web Vitals because it is important for SEO, then some folks will undoubtedly try to game the system.

Personally, my beef with core web vitals is that they introduce even more uneccessary initialisms (see, for example, Harry’s recent post where he uses CWV metrics like LCP, FID, and CLS—alongside TTFB and SI—to look at PLPs, PDPs, and SRPs. I mean, WTF?).

Friday, November 13th, 2020

Chris Ferdinandi: The Lean Web – WordPress.tv

This video of Chris’s presentation is well worth watching:

The web in 2020 is a bloated and over-engineered mess! Many modern web development “best practices” are making the web worse. This thought-provoking talk shares ideas on how to fix the problem as it explores an alternate set of best practices.

Thursday, November 12th, 2020

Web Platform Design Principles

Principles behind the design of web APIs:

  • Put user needs first (Priority of Constituencies)
  • It should be safe to visit a web page
  • Trusted user interface should be trustworthy
  • Ask users for meaningful consent when appropriate
  • Support the full range of devices and platforms (Media Independence)

I should add these to my collection.

Official Google Webmaster Central Blog: Timing for bringing page experience to Google Search

Good news: as of May 2021, page speed (or core web vitals, if you must) will be a ranking factor in Google Search.

Even better news: at the same time, Google AMP will lose its unfairly privileged position in the top stories carousel. Hopefully this marks the beginning of the end for Google’s failed experiment in forcing publishers to use their tech.

Tuesday, November 10th, 2020

HTML Forms: How (and Why) to Prevent Double Form Submissions – Bram.us

I can see how this would be good to have fixed at the browser level.

Wednesday, October 28th, 2020

Portals and giant carousels

I posted something recently that I think might be categorised as a “shitpost”:

Most single page apps are just giant carousels.

Extreme, yes, but perhaps there’s a nugget of truth to it. And it seemed to resonate:

I’ve never actually seen anybody justify SPA transitions with actual business data. They generally don’t seem to increase sales, conversion, or retention.

For some reason, for SPAs, managers are all of a sudden allowed to make purely emotional arguments: “it feels snappier”

If businesses were run rationally, when somebody asks for an order of magnitude increase in project complexity, the onus would be on them to prove that it proportionally improves business results.

But I’ve never actually seen that happen in a software business.

A single page app architecture makes a lot of sense for interaction-heavy sites with lots of state to maintain, like twitter.com. But I’ve seen plenty of sites built as single page apps even though there’s little to no interactivity or state management. For some people, it’s the default way of building anything on the web, even a brochureware site.

It seems like there’s a consensus that single page apps may have long initial loading times, but then they have quick transitions between “pages” …just like a carousel really. But I don’t know if that consensus is based on reality. Whether you’re loading a page of HTML or loading a chunk of JSON, you’re still making a network request that will take time to resolve.

The argument for loading a chunk of JSON is that you don’t have to make any requests for the associated CSS and JavaScript—they’re already loaded. Whereas if you request a page of HTML, that HTML will also request CSS and JavaScript.

Leaving aside the fact that is literally what the browser cache takes of, I’ve seen some circular reasoning around this:

  1. We need to create a single page app because our assets, like our JavaScript dependencies, are so large.
  2. Why are the JavaScript dependencies so large?
  3. We need all that JavaScript to create the single page app functionlity.

To be fair, in the past, the experience of going from page to page used to feel a little herky-jerky, even if the response times were quick. You’d get a flash of a white blank page between navigations. But that’s no longer the case. Browsers now perform something called “paint holding” which elimates the herky-jerkiness.

So now if your pages are a reasonable size, there’s no practical difference in user experience between full page refreshes and single page app updates. Navigate around The Session if you want to see paint holding in action. Switching to a single page app architecture wouldn’t improve the user experience one jot.


If I were controlling everything with JavaScript, then I’d also have control over how to transition between the “pages” (or carousel items, if you prefer). There’s currently no way to do that with full page changes.

This is the problem that Jake set out to address in his proposal for navigation transitions a few years back:

Having to reimplement navigation for a simple transition is a bit much, often leading developers to use large frameworks where they could otherwise be avoided. This proposal provides a low-level way to create transitions while maintaining regular browser navigation.

I love this proposal. It focuses on user needs. It also asks why people reach for JavaScript frameworks instead of using what browsers provide. People reach for JavaScript frameworks because browsers don’t yet provide some functionality: components like tabs or accordions; DOM diffing; control over styling complex form elements; navigation transitions. The problems that JavaScript frameworks are solving today should be seen as the R&D departments for web standards of tomorrow. (And conversely, I strongly believe that the aim of any good JavaScript framework should be to make itself redundant.)

I linked to Jake’s excellent proposal in my shitpost saying:

bucketloads of JavaScript wouldn’t be needed if navigation transitions were available in browsers

But then I added—and I almost didn’t—this:

(not portals)

Now you might be asking yourself what Paul said out loud:

Excuse my ignorance but… WTF are portals!?

I replied with a link to the portals proposal and what I thought was an example use case:

Portals are a proposal from Google that would help their AMP use case (it would allow a web page to be pre-rendered, kind of like an iframe).

That was based on my reading of the proposal:

…show another page as an inset, and then activate it to perform a seamless transition to a new state, where the formerly-inset page becomes the top-level document.

It sounded like Google’s top stories carousel. And the proposal goes into a lot of detail around managing cross-origin requests. Again, that strikes me as something that would be more useful for a search engine than a single page app.

But Jake was not happy with my description. I didn’t intend to besmirch portals by mentioning Google AMP in the same sentence, but I can see how the transitive property of ickiness would apply. Because Google AMP is a nasty monopolistic project that harms the web and is an embarrassment to many open web advocates within Google, drawing any kind of comparison to AMP is kind of like Godwin’s Law for web stuff. I know that makes it sounds like I’m comparing Google AMP to Hitler, and just to be clear, I’m not (though I have myself been called a fascist by one of the lead engineers on AMP).

Clearly, emotions run high when Google AMP is involved. I regret summoning its demonic presence.

After chatting with Jake some more, I tried to find a better use case to describe portals. Reading the proposal, portals sound a lot like “spicy iframes”. So here’s a different use case that I ran past Jake: say you’re on a website that has an iframe embedded in it—like a YouTube video, for example. With portals, you’d have the ability to transition the iframe to a fully-fledged page smoothly.

But Jake told me that even though the proposal talks a lot about iframes and cross-origin security, portals are conceptually more like using rel="prerender" …but then having scripting control over how the pre-rendered page becomes the current page.

Put like that, portals sound more like Jake’s original navigation transitions proposal. But I have to say, I never would’ve understood that use case just from reading the portals proposal. I get that the proposal is aimed more at implementators than authors, but in its current form, it doesn’t seem to address the use case of single page apps.

Kenji said:

we haven’t seen interest from SPA folks in portals so far.

I’m not surprised! He goes on:

Maybe, they are happy / benefits aren’t clear yet.

From my own reading of the portals proposal, I think the benefits are definitely not clear. It’s almost like the opposite of Jake’s original proposal for navigation transitions. Whereas as that was grounded in user needs and real-world examples, the portals proposal seems to have jumped to the intricacies of implementation without covering the user needs.

Don’t get me wrong: if portals somehow end up leading to a solution more like Jake’s navigation transitions proposals, then I’m all for that. That’s the end result I care about. I’d love it if people had a lightweight option for getting the perceived benefits of single page apps without the costly overhead in performance that comes with JavaScripting all the things.

I guess the web I want includes giant carousels.

Sunday, October 18th, 2020

People Problems | CSS-Tricks

I’d maybe simplify this people problem a bit: the codebase is easy to change, but the incentives within a company are not. And yet it’s the incentives that drive what kind of code gets written — what is acceptable, what needs to get fixed, how people work together. In short, we cannot be expected to fix the code without fixing the organization, too.

Wednesday, October 14th, 2020

How-to: Create accessible forms - The A11Y Project

Another five pieces of sweet, sweet low-hanging fruit:

  • Always label your inputs.
  • Highlight input element on focus.
  • Break long forms into smaller sections.
  • Provide error messages.
  • Avoid horizontal layout forms unless necessary.

Saving forms

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.