Tags: aria



Friday, September 6th, 2019

Recursive | Recursive

Play around with this variable font available soon from Google Fonts in monospaced and sans-serif versions.

Saturday, August 31st, 2019

Friday, August 9th, 2019

Meaning without markup: Accessibility Object Model

Hidde gives an in-depth explanation of the Accessibility Object Model, coming soon to browsers near you:

In a way, that’s a bit like what Service Workers do for the network and Houdini for style: give developers control over something that was previously done only by the browser.

Tuesday, July 30th, 2019

Thursday, July 25th, 2019


I like good design principles. I collect design principles—of varying quality—at principles.adactio.com. Ben Brignell also has a (much larger) collection at principles.design.

You can spot the less useful design principles after a while. They tend to be wishy-washy; more like empty aspirational exhortations than genuinely useful guidelines for alignment. I’ve written about what makes for good design principles before. Matthew Ström also asked—and answered—What makes a good design principle?

  • Good design principles are memorable.
  • Good design principles help you say no.
  • Good design principles aren’t truisms.
  • Good design principles are applicable.

I like those. They’re like design principles for design principles.

One set of design principles that I’ve included in my collection is from gov.uk: government design principles . I think they’re very well thought-through (although I’m always suspicious when I see a nice even number like 10 for the amount of items in the list). There’s a great line in design principle number two—Do less:

Government should only do what only government can do.

This wasn’t a theoretical issue. The multiple departmental websites that preceded gov.uk were notorious for having too much irrelevant content—content that was readily available elsewhere. It was downright wasteful to duplicate that content on a government site. It wasn’t appropriate.

Appropriateness is something I keep coming back to when it comes to evaluating web technologies. I don’t think there are good tools and bad tools; just tools that are appropriate or inapropriate for the task at hand. Whether it’s task runners or JavaScript frameworks, appropriateness feels like it should be the deciding factor.

I think that the design principle from GDS could be abstracted into a general technology principle:

Any particular technology should only do what only that particular technology can do.

Take JavaScript, for example. It feels “wrong” when a powerful client-side JavaScript framework is applied to something that could be accomplished using HTML. Making a blog that’s a single page app is over-engineering. It violates this principle:

JavaScript should only do what only JavaScript can do.

Need to manage state or immediately update the interface in response to user action? Only JavaScript can do that. But if you need to present the user with some static content, JavaScript can do that …but it’s not the only technology that can do that. HTML would be more appropriate.

I realise that this is basically a reformulation of one of my favourite design principles, the rule of least power:

Choose the least powerful language suitable for a given purpose.

Or, as Derek put it:

In the web front-end stack — HTML, CSS, JS, and ARIA — if you can solve a problem with a simpler solution lower in the stack, you should. It’s less fragile, more foolproof, and just works.

ARIA should only do what only ARIA can do.

JavaScript should only do what only JavaScript can do.

CSS should only do what only CSS can do.

HTML should only do what only HTML can do.

Monday, July 1st, 2019

Variable Fonts for Developers

A showcase of fun experiments with variable fonts, courtesy of Mandy.

Sunday, June 9th, 2019

German Naming Convention

Don’t write fopen when you can write openFile. Write throwValidationError and not throwVE. Call that name function and not fct. That’s German naming convention. Do this and your readers will appreciate it.

Friday, June 7th, 2019

An Introduction to ARIA States | a11y with Lindsey

A very useful explanation of the ARIA attributes relating to state:

  1. aria-expanded,
  2. hidden,
  3. aria-hidden, and
  4. aria-current.

Wednesday, May 22nd, 2019

Accessible Icon Buttons — Sara Soueidan – Freelance-Front-End UI/UX Developer

Sara runs through the many ways of providing an accessible name to an icon button, backed up with Scott’s testing.

Making Future Interfaces: Custom Properties - YouTube

Heydon cracks me up—his Patterns Day is going to have you crying with laughter; guaranteed!

Here he is talking about custom properties in CSS as part of his Making Future Interfaces video series.

Thursday, April 18th, 2019

Inlining SVG background images in CSS with custom properties

Here’s a tiny lesson that I picked up from Trys that I’d like to share with you…

I was working on some upcoming changes to the Clearleft site recently. One particular component needed some SVG background images. I decided I’d inline the SVGs in the CSS to avoid extra network requests. It’s pretty straightforward:

.myComponent {
    background-image: url('data:image/svg+xml;utf8,<svg> ... </svg>');

You can basically paste your SVG in there, although you need to a little bit of URL encoding: I found that converting # to %23 to was enough for my needs.

But here’s the thing. My component had some variations. One of the variations had multiple background images. There was a second background image in addition to the first. There’s no way in CSS to add an additional background image without writing a whole background-image declaration:

.myComponent--variant {
    background-image: url('data:image/svg+xml;utf8,<svg> ... </svg>'), url('data:image/svg+xml;utf8,<svg> ... </svg>');

So now I’ve got the same SVG source inlined in two places. That negates any performance benefits I was getting from inlining in the first place.

That’s where Trys comes in. He shared a nifty technique he uses in this exact situation: put the SVG source into a custom property!

:root {
    --firstSVG: url('data:image/svg+xml;utf8,<svg> ... </svg>');
    --secondSVG: url('data:image/svg+xml;utf8,<svg> ... </svg>');

Then you can reference those in your background-image declarations:

.myComponent {
    background-image: var(--firstSVG);
.myComponent--variant {
    background-image: var(--firstSVG), var(--secondSVG);

Brilliant! Not only does this remove any duplication of the SVG source, it also makes your CSS nice and readable: no more big blobs of SVG source code in the middle of your style sheet.

You might be wondering what will happen in older browsers that don’t support CSS custom properties (that would be Internet Explorer 11). Those browsers won’t get any background image. Which is fine. It’s a background image. Therefore it’s decoration. If it were an important image, it wouldn’t be in the background.

Progressive enhancement, innit?

Wednesday, March 20th, 2019

CSS custom properties in generated content

Cassie posted a neat tiny lesson that she’s written a reduced test case for.

Here’s the situation…

CSS custom properties are fantastic. You can drop them in just about anywhere that a property takes a value.

Here’s an example of defining a custom property for a length:

:root {
    --my-value: 1em;

Then I can use that anywhere I’d normally give something a length:

.my-element {
    margin-bottom: var(--my-value);

I went a bit overboard with custom properties on the new Patterns Day site. I used them for colour values, font stacks, and spacing. Design tokens, I guess. They really come into their own when you combine them with media queries: you can update the values of the custom properties based on screen size …without having to redefine where those properties are applied. Also, they can be updated via JavaScript so they make for a great common language between CSS and JavaScript: you can define where they’re used in your CSS and then update their values in JavaScript, perhaps in response to user interaction.

But there are a few places where you can’t use custom properties. You can’t, for example, use them as part of a media query. This won’t work:

@media all and (min-width: var(--my-value)) {

You also can’t use them in generated content if the value is a number. This won’t work:

:root {
    --number-value: 15;
.my-element::before {
    content: var(--number-value);

Fair enough. Generated content in CSS is kind of a strange beast. Eric delivered an entire hour-long talk at An Event Apart in Seattle on generated content.

But Cassie found a workaround if the value you want to put into that content property is numeric. The CSS counter value is a kind of generated content—the numbers that appear in front of ordered list items. And you can control the value of those numbers from CSS.

CSS counters work kind of like variables. You name them and assign values to them using the counter-reset property:

.my-element {
    counter-reset: mycounter 15;

You can then reference the value of mycounter in a content property using the counter value:

.my-element {
    content: counter(mycounter);

Cassie realised that even though you can’t pass in a custom property directly to generated content, you can pass in a custom property to the counter-reset property. So you can do this:

:root {
    --number-value: 15;
.my-element {
    counter-reset: mycounter var(--number-value);
    content: counter(mycounter);

In a roundabout way, this allows you to use a custom property for generated content!

I realise that the use cases are pretty narrow, but I can’t help but be impressed with the thinking behind this. Personally, I would’ve just read that generated content doesn’t accept custom properties and moved on. I would’ve given up quickly. But Cassie took a step back and found a creative pass-the-parcel solution to the problem.

I feel like this is a hack in the best sense of the word: a creatively improvised solution to a problem or limitation.

I was trying to display the numeric value stored in a CSS variable inside generated content… Turns out you can’t do that. But you can do this… codepen.io/cassie-codes/p… (not saying you should, but you could)

Wednesday, March 13th, 2019

The web we broke. — Ethan Marcotte

Like Eric, Ethan is feeling rightly glum about the state of accessibility on the web. But…

Right now, I’m trying to focus on this one question:

What’s one thing I wish I understood better about accessibility?

Fighting uphill | Eric Bailey

Eric is down about the current dismal state of accessibility on the web. Understandably so. It’s particularly worrying that the problem might be embedded into hiring practices:

Overwhelmingly, crushingly, we shove new developers towards learning JavaScript single page application frameworks (SPAs). While many of these frameworks pay lip service towards preserving accessibility, if you do your homework you find that the majority of them were built without assistive technology in mind.

But it’s not all doom and gloom. Eric also points to initiatives that could really help.

Still, this is a tough question to ask out loud:

What if we’re losing?

Monday, February 25th, 2019

Accessibility on The Session

I spent some time this weekend working on an accessibility issue over on The Session. Someone using VoiceOver on iOS was having a hard time with some multi-step forms.

These forms have been enhanced with some Ajax to add some motion design: instead of refreshing the whole page, the next form is grabbed from the server while the previous one swooshes off the screen.

You can see similar functionality—without the animation—wherever there’s pagination on the site.

The pagination is using Ajax to enhance regular prev/next links—here’s the code.

The multi-step forms are using Ajax to enhance regular form submissions—here’s the code for that.

Both of those are using a wrapper I wrote for XMLHttpRequest.

That wrapper also adds some ARIA attributes. The region of the page that will be updated gets an aria-live value of polite. Then, whenever new content is being injected, the same region gets an aria-busy value of true. Once the update is done, the aria-busy value gets changed back to false.

That all seems to work fine, but I was also giving the same region of the page an aria-atomic value of true. My thinking was that, because the whole region was going to be updated with new content from the server, it was safe to treat it as one self-contained unit. But it looks like this is what was causing the problem, especially when I was also adding and removing class values on the region in order to trigger animations. VoiceOver seemed to be getting a bit confused and overly verbose.

I’ve removed the aria-atomic attribute now. True to its name, I’m guessing it’s better suited to small areas of a document rather than big chunks. (If anyone has a good primer on when to use and when to avoid aria-atomic, I’m all ears).

I was glad I was able to find a fix—hopefully one that doesn’t negatively impact the experience in other screen readers. As is so often the case, the issue was with me trying to be too clever with ARIA, and the solution was to ease up on adding so many ARIA attributes.

It also led to a nice discussion with some of the screen-reader users on The Session.

For me, all of this really highlights the beauty of the web, when everyone is able to contribute to a community like The Session, regardless of what kind of software they may be using. In the tunes section, that’s really helped by the use of ABC notation, as I wrote five years ago:

One of those screen-reader users got in touch with me shortly after joining to ask me to explain what ABC was all about. I pointed them at some explanatory links. Once the format “clicked” with them, they got quite enthused. They pointed out that if the sheet music were only available as an image, it would mean very little to them. But by providing the ABC notation alongside the sheet music, they could read the music note-for-note.

That’s when it struck me that ABC notation is effectively alt text for sheet music!

Then, for those of use who can read sheet music, the text of the ABC notation is automatically turned into an SVG image using the brilliant abcjs. It’s like an enhancement that’s applied, I dunno, what’s the word …progressively.

Tuesday, February 5th, 2019

Revisiting the abbr element

Ire takes a deep dive into implementing an accessible tool tip.

Sunday, January 27th, 2019

Make Your ARIA Labels Sing on Key — Knowbility

A good look at the (over)use of the aria-label attribute that confirms the first rule of ARIA.

Friday, January 11th, 2019

Stepping away from Sass

I think Cathy might’ve buried the lede:

The knock on effect of this was removing media queries. As I moved towards some of the more modern features of CSS the need to target specific screen sizes with unique code was removed.

But on the topic of Sass, layout is now taken care of with CSS grid, variables are taken care of with CSS custom properties, and mixins for typography are taken care of with calc().

Personally, I’ve always found the most useful feature of Sass to simply be that you can have lots of separate Sass files that get combined into one CSS file—very handy for component libraries.

Saturday, December 15th, 2018

Using aria-live

A terrific explanation of the aria-live attribute from Ire. If you’re doing anything with Ajax, this is vital knowledge.

Saturday, November 17th, 2018

Difference between currentColor & Custom Properties | Mike Riethmuller

I had to read through this twice, but I think I get it now (I’m not the sharpest knife in the drawer). Very useful if you’re doing theming in CSS.