Tags: frontend

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Tuesday, December 15th, 2020

Are your Anchor Links Accessible? | Amber Wilson

I really like the way that Amber doesn’t go straight to the end solution but instead talks through her thought process when adding a feature to her site.

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.

<style>
element {
    property: value;
}
</style>

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).

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

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">
</element>

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

Lists

We often have brown bag lunchtime presentations at Clearleft. In the Before Times, this would involve a trip to Pret or Itsu to get a lunch order in, which we would then proceed to eat in front of whoever was giving the presentation. Often it’s someone from Clearleft demoing something or playing back a project, but whenever possible we’d rope in other people to swing by and share what they’re up to.

We’ve continued this tradition since making the switch to working remotely. Now the brown bag presentations happen over Zoom. This has two advantages. Firstly, if you don’t want the presenter watching you eat your lunch, you can switch your camera off. Secondly, because the presenter doesn’t have to be in Brighton, there’s no geographical limit on who could present.

Our most recent brown bag was truly excellent. I asked Léonie if she’d be up for it, and she very kindly agreed. As well as giving us a whirlwind tour of how assistive technology works on the web, she then invited us to observe her interacting with websites using a screen reader.

I’ve seen Léonie do this before and it’s always struck me as a very open and vulnerable thing to do. Think about it: the audience has more information than the presenter. We can see the website at the same time as we’re listening to Léonie and her screen reader.

We got to nominate which websites to visit. One of them—a client’s current site that we haven’t yet redesigned—was a textbook example of how important form controls are. There was a form where almost everything was hunky-dory: form fields, labels, it was all fine. But one of the inputs was a combo box. Instead of using a native select with a datalist, this was made with JavaScript. Because it was lacking the requisite ARIA additions to make it accessible, it was pretty much unusable to Léonie.

And that’s why you use the right HTML element wherever possible, kids!

The other site Léonie visited was Clearleft’s own. That was all fine. Léonie demonstrated how she’d form a mental model of a page by getting the screen reader to read out the headings. Interestingly, the nesting of headings on the Clearleft site is technically wrong—there’s a jump from an h1 to an h3—probably a result of the component-driven architecture where you don’t quite know where in the page a heading will appear. But this didn’t seem to be an issue. The fact that headings are being used at all was the more important fact. As Léonie said, there’s a lot of incorrect HTML out there so it’s no wonder that screen readers aren’t necessarily sticklers for nesting.

I’ve said it before and I’ll say it again: if you’re using headings, labelling form fields, and providing alternative text for images, you’re already doing a better job than most websites.

Headings weren’t the only way that Léonie got a feel for the page architecture. Landmark roles—like header and nav—really helped too. Inside the nav element, she also heard how many items there were. That’s because the navigation was marked up as a list: “List: six items.”

And that reminded me of the Webkit issue. On Webkit browsers like Safari, the list on the Clearleft site would not be announced as a list. That’s because the lists’s bullets have been removed using CSS.

Now this isn’t the only time that screen readers pay attention to styling. If you use display: none to hide an element from sight, it will also be unavailable to screen reader users. Makes sense. But removing the semantic meaning of lists based on CSS? That seems a bit much.

There are good reasons for it though. Here’s a thread from James Craig on where this decision came from (James, by the way, is an absolute unsung hero of accessibility). It turns out that developers went overboard with lists a while back and that’s why we can’t have nice things. In over-compensating from divitis, developers ended up creating listitis, marking up anything vaguely list-like as an unordered list with styling adjusted. That was very annoying for screen reader users trying to figure out what was actually a list.

And James also asks:

If a sighted user doesn’t need to know it’s a list, why would a screen reader user need to know or want to know? Stated another way, if the visible list markers (bullets, image markers, etc.) are deemed by the designers to be visually burdensome or redundant for sighted users, why burden screen reader users with those semantics?

That’s a fair point, but the thing is …bullets maketh not the list. There are many ways of styling something that is genuinely a list that doesn’t involve bullets or image markers. White space, borders, keylines—these can all indicate visually that something is a list of items.

If you look at, say, the tunes page on The Session, you can see that there are numerous lists—newest tunes, latest comments, etc. In this case, as a sighted visitor, you would be at an advantage over a screen reader user in that you can, at a glance, see that there’s a list of five items here, a list of ten items there.

So I’m not disagreeing with the thinking behind the Webkit decision, but I do think the heuristics probably aren’t going to be quite good enough to make the call on whether something is truly a list or not.

Still, while I used to be kind of upset about the Webkit behaviour, I’ve become more equanimous about it over time. There are two reasons for this.

Firstly, there’s something that Eric said:

We have come so far to agree that websites don’t need to look the same in every browser mostly due to bugs in their rendering engines or preferences of the user.

I think the same is true for screen readers and other assistive technology: Websites don’t need to sound the same in every screen reader.

That’s a really good point. If we agree that “pixel perfection” isn’t attainable—or desirable—in a fluid, user-centred medium like the web, why demand the aural equivalent?

The second reason why I’m not storming the barricades about this is something that James said:

Of course, heuristics are imperfect, so authors have the ability to explicitly override the heuristically determined role by adding role="list”.

That means more work for me as a developer, and that’s …absolutely fine. If I can take something that might be a problem for a user, and turn into something that’s a problem for me, I’ll choose to make it my problem every time.

I don’t have to petition Webkit to change their stance or update their heuristics. If I feel strongly that a list styled without bullets should still be announced as a list, I can specificy that in the markup.

It does feel very redundant to write ul role="list”. The whole point of having HTML elements with built-in semantics is that you don’t need to add any ARIA roles. But we did it for a while when new structural elements were introduced in HTML5—main role="main", nav role="navigation", etc. So I’m okay with a little bit of redundancy. I think the important thing is that you really stop and think about whether something should be announced as a list or not, regardless of styling. There isn’t a one-size-fits-all answer (hence why it’s nigh-on impossible to get the heuristics right). Each list needs to be marked up on a case-by-case basis.

And I wouldn’t advise spending too much time thinking about this either. There are other, more important areas to consider. Like I said, headings, forms, and images really matter. I’d prioritise those elements above thinking about lists. And it’s worth pointing out that Webkit doesn’t remove all semantic meaning from styled lists—it updates the role value from list to group. That seems sensible to me.

In the case of that page on The Session, I don’t think I’m guilty of listitis. Yes, there are seven lists on that page (two for navigation, five for content) but I’m reasonably confident that they all look like lists even without bullets or markers. So I’ve added role="list" to some ul elements.

As with so many things related to accessibility—and the web in general—this is a situation where the only answer I can confidentally come up with is …it depends.

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.

EStimator.dev: the modern JavaScript savings calculator

Find out how much smaller your JavaScript could be.

Saturday, December 12th, 2020

What Can You Put in a CSS Variable? / Coder’s Block

A reminder that the contens of custom properties don’t have to be valid property values:

From a syntax perspective, CSS variables are “extremely permissive”.

Thursday, December 10th, 2020

The Importance of HTML – Jerry Jones

You’re not going to get a Webby Award or thousands of views on Codepen for how amazingly crafted your HTML is. You’ll need to be OK going unrecognized for your work. But know that every time I use a screen reader or keyboard on a site and it works correctly, I have a little spark of joy.

Wednesday, December 9th, 2020

npm ruin dev | CSS-Tricks

Chris is gathering end-of-year thoughts from people in response to the question:

What is one thing you learned about building websites this year?

Here’s mine.

In 2020, I rediscovered the enjoyment of building a website with plain ol’ HTML, CSS, and JavaScript — no transpilin’, no compilin’, no build tools other than my hands on the keyboard.

Tuesday, December 8th, 2020

What Makes CSS Hard To Master - Tim Severien

CSS is simple, but not easy.

If we, as a community, start to appreciate the complexity of writing CSS, perhaps we can ask for help instead of blaming the language when we’re confused or stuck. We might also stop looking down on CSS specialists.

Wednesday, December 2nd, 2020

Creating websites with prefers-reduced-data | Polypane Browser for Developers

There’s no browser support yet but that doesn’t mean we can’t start adding prefers-reduced-data to our media queries today. I like the idea of switching between web fonts and system fonts.

Sunday, November 29th, 2020

Rendering Spectrum | CSS-Tricks

Sensible advice from Chris:

So what’s the best rendering method? Whatever works best for you, but perhaps a hierarchy like this makes some general sense:

  1. Static HTML as much as you can
  2. Edge functions over static HTML so you can do whatever dynamic things
  3. Server generated HTML what you have to after that
  4. Client-side render only what you absolutely have to

Sunday, November 22nd, 2020

Static sites, slack and scrollytelling. | Clearleft

Cassie’s enthusiasm for fun and interesting SVG animation shines through in her writing!

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.

Amen!

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?).

CSS Stats

A handy tool for getting an overview of your site’s CSS:

CSS Stats provides analytics and visualizations for your stylesheets. This information can be used to improve consistency in your design, track performance of your app, and diagnose complex areas before it snowballs out of control.

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

Caching and storing

When I was speaking at conferences last year about service workers, I’d introduce the Cache API. I wanted some way of explaining the difference between caching and other kinds of storage.

The way I explained was that, while you might store stuff for a long time, you’d only cache stuff that you knew you were going to need again. So according to that definition, when you make a backup of your hard drive, that’s not caching …becuase you hope you’ll never need to use the backup.

But that explanation never sat well with me. Then more recently, I was chatting with Amber about caching. Once again, we trying to define the difference between, say, the Cache API and things like LocalStorage and IndexedDB. At some point, we realised the fundamental difference: caches are for copies.

Think about it. If you store something in LocalStorage or IndexedDB, that’s the canonical home for that data. But anything you put into a cache must be a copy of something that exists elsewhere. That’s true of the Cache API, the browser cache, and caches on the server. An item in one of those caches is never the original—it’s always a copy of something that has a canonical home elsewhere.

By that definition, backing up your hard drive definitely is caching.

Anyway, I was glad to finally have a working definition to differentiate between caching and storing.

All Them Switches: Responsive Elements and More

Container queries are like buses: you’re waiting for ages and then two come along at once.

This switch() syntax looks interesting.

An opinionated guide to accessibility testing /// Iain Bean

  1. First impressions
  2. The Tab key
  3. Automated testing tools
  4. Screen reader testing
  5. Next steps

Wednesday, November 11th, 2020

Not so short note on aria-label usage – Big Table Edition – HTML Accessibility

This is a very handy table of elements from Steve of where aria-label can be applied.

Like, for example, not on a div element.