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Tag: web-development

A11y 101: 2.1.2 No Keyboard Trap

Admiral Ackbar is letting us know something important. When we navigate by keyboard, we need to make certain of one thing. Make sure that a user doesn’t get trapped with no where to go.

This seems really simple, but it gets complicated quickly. And I know what seems simple to one person is traumatically difficult for another. Let’s talk about what a trap is, some examples, and ways to prevent them.

What is a keyboard trap?

A keyboard trap is any control that receives focus, but does not release it. Usually, the keyboard is trapped from moving in any direction. Sometimes it may be trapped in one direction, generally forward.

I’ve encountered some that prevent moving forward, but allow moving backward. Usually this presents a workaround, but not always. Even if there is a word around, it is still a violation.

Often developers will put a “forward” action on an input when the content meets a certain regex or pattern. This is difficult because the input is saying, “If I have 5 numbers, tab to the next control.” This becomes a keyboard trap as the keyboard only user cannot tab back into the field to correct it.

More common though is a disclosure control that isn’t following the <h3><button>Title</button><h3> pattern. Often the button is somewhere else or outside the heading. When the control is in focus, nothing happens.

How do we test?

If you do not need a screen reader to understand the screen, turn it off. If you require a screen reader, put it in forms mode. Forms mode will only respond to Tabbing and form control with the default keys. We don’t want interference from the AT.

Tab. Again. Shift tab. Keep using tab to navigate through the page, and do it in reverse. If you get stuck, try using the Escape key. Did that get you out? if yes, did it push you backwards or forwards?

If you find you can escape the trap, try repeating the situation in both directions multiple times. If you got out, this belongs in usability advice. If you can’t get out or can’t move in both directions, you have a violation.

What is the cause?

In most cases of keyboard traps, the cause is going to be JavaScript. Typically there is a function tied to the field being focused or activated. This can cause a race condition freezing the browser. More likely, there is function that prevents tabbing out, or the function tied to moving out is not firing.

Take the object where the keyboard trap is happening. Reproduce it locally, then start stripping back all that is tied to it. For example, if you are using custom dropdown, remove all the custom code. Begin with the base HTML <select> and <option> elements.

Is there still a keyboard trap? If you extracted all JS hooks and custom HTML, there should be no trap. Once we establish that the basic HTML works, let’s expose the custom HTML.

Hide any classes tied to JS functions. Remove data attributes. Get the JS out of the way. And try it again. Is it stuck now? Then it is time to examine out HTML again. No, then we slowly start adding in JS one item at a time until we find out trap.

Time to fix it

I cannot really tell you how long to remediate this would be. Everyone’s architecture is different and will cause different problems in different ways. But finding the trap’s location might take a day. Determining the cause could also take time, even for the most skilled developer. I recall early on spending 10 hours searching for an error in my code. It turned out to be the dreaded missing semicolon. It happens to all of us. Its about how do we fix it once we know of it.

Have questions? Come talk to me on LinkedIn or BlueSky!

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K.I.S.S. ARIA

Keep It Silly Simple

I sat down to review some code with my colleagues. It was clear that each of these solutions was heavily over-engineered. Each used custom web components, React, Angular, or other framework, and even basic HTML with aria added. All of them should get slimmed down and work to reduce or remove ARIA.

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A11y 101: 1.3.2 Meaningful Sequence

The order of consumption of media affects its meaning.

As an 80s kid, I learned that the placement of a comma can change a sentence’s meaning. Of course we learned it through dirty jokes:

  • i helped my uncle jack off a horse
  • I helped my uncle Jack, off a horse.
  • I helped my uncle, jack off a horse.
  • I helped my uncle, Jack, off a horse.

Even the order makes a big difference:

  • I helped my uncle off a horse, Jack.
  • I helped Jack, my uncle, off a horse.

When we write and layout our document, we need to consider the rendered HTML and CSS. We also need to consider the HTML on its own. Some of your users will use tools to absorb the content in different manners.

We need to ensure a meaningful sequences when at the word, sentence, paragraph, article, and component level. We want to develop a meaningful order at the document level also. Usually we do this through landmarks or the use of headings to designate areas of the content. Depending on the relationships of the content, areas could dictate the understanding of the document. So does the header, footer, or main have to follow a certain order? Our instinct is to go header, main, footer. What if our HTML was Main, header, footer and we use CSS to visually move the navigation?

But should we?

Stepping in from the document level, there are things to consider within each component – visual presentation and content presentation. Look at these two cards:

See the Pen 1.3.2 Meaningful Sequence by Nat Tarnoff (@nattarnoff) on CodePen.

Without looking (I saw you look at the HTML tab), you might guess how this is coded. You’d likely think it is Card Title, CTA, image, paragraph, list. And you’d be pretty close. Next you’re thinking, “Ah, image first, that’s how cards are done.”

Both cards have this structure:

<div class="card" id="card1">
    <h2>Card Title</h2>
    <img src="https://placecats.com/millie_neo/300/200" alt="Millie & Neo resting on the cat tree."/>
    <p>Kool kats & kittens at the library!</p>
    <ul>
      <li>Where: Main Street Library</li>
      <li>When: 1pm to 4pm</li>
      <li>Day: Saturday 1/23</li>
    </ul>
    <button type="button">RSVP</button>
  </div>

We can move the content around using CSS. Are the details are more important than the image or the tagline? We try Title, Details, CTA, paragraph, and image. When we are at this stage of developing the code, it’s important to just focus on how the page reads. The two versions of the HTML do not effectively change the meaning of any of the content. Nor do they interfere with the visual display.

How do we fix the meaningful sequence?

We start by looking at individual pieces of content. Let’s start with a button. A button will fire an action, so I need to give it an accessible name to reflect that. I can add a pre-icon, and post-icon, and I know I’ll have at least two states. If I have visible text, then the icons don’t need alt text.

Step two, after styling the most basic of elements, we pair them together. We’re going to use our button to make a search component. This means I need a label, an input, and a way to fire the search. We’re keeping this simple to begin. We’ll use a button and a post action so the page refreshes with results. Most developers will code this label, input, button. But they don’t have to be in that order.

<div class="search-widget">
<input type="search" id="search" aria-labelledby="title"/>
<button id="title" type="submit"><img src="magnifier.png" alt="Search" /></button>
</div>

An easily recognizable or learnable icon can be used as a label as above. We of course provide the alt text. We can use the alt text of the icon in the button as the label for the form. We can change the order visually and it has no effect on how a non-visual user would understand it.

Break up content into the smallest functional pieces. Make sure each piece is understood fully within itself in a meaningful sequence. Then start layering those into the page document in the order to use them. A sales page would have account information first. Then it would include the client’s dashboard. Next, it provides access to individual child accounts. Finally, it lists leads and sales. There is a sidebar to do some research or note taking. We probably have some account screen for the sales person as well. Within each of those sections they’ll have an order that makes sense.

But at a page level the “main” content will be the what the user wants the most. So we put it first. Don’t run away yet. Initially, the order of the main section doesn’t matter. As this user gets used to it, they may want to show and hide different widgets. They might even want to move them. Let’s put a plan in place for that. We don’t want to forget our sidebar, main nav, or account information. These need to be placed in based on order of importance to the user at the code level. When you turn to CSS to position and decorate, is when we get the visual design.

Its always best to do user research on new products. An application like we describe above will benefit from interviewing the potential users. Then within the design, marketing, executive, and client teams conduct some card sorting exercises. Keep repeating this as you develop and design the application. You may find you need to change your design or users didn’t think like you thought they would.

Have more questions? Let’s discuss it over on LinkedIn or BlueSky!

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