Accessibility

Toggletip widget pattern (tooltip alternative)

Image

What it does

  • Uses a real button as a control.
  • Places the displayed content next in DOM order after the button.
  • Uses some ARIA magic to augment the semantics and behaviour.
  • Displays or dismisses content on click, press or tap (also dismisses on esc key press).
  • Conveys state (collapsed or expanded) to AT users.
  • When initially displayed content is announced by (most) screen readers that support aria-live.
  • Screen readers users can also virtual cursor through and interact with the displayed content.
  • keyboard only users can interact with controls in the displayed content.

What it does not do

Display content on mouse cursor hover.

View Toggletip demo on CodePen

Using the aria-current attribute

It is common on the web for the current thing in a collection to be highlighted visually, but providing an alternative for screen reader users has often involved something of a hack. The aria-current attribute is intended to solve this problem.

[…]

Here’s the official attribute definition:

Indicates the element that represents the current item within a container or set of related elements. The aria-current attribute is an enumerated type. Any value not included in the list of allowed values should be treated by assistive technologies as if the value true had been provided. If the attribute is not present or its value is an empty string, the default value of false applies and the aria-current state must not be exposed by user agents or assistive technologies.

According to the ARIA 1.1 specification, the aria-current attribute can be given one of a predefined set of values (enumerated tokens):

page
represents the current page within a set of pages;
step
represents the current step within a process;
location
represents the current location within an environment or context;
date
represents the current date within a collection of dates;
time
represents the current time within a set of times;
true
represents the current item within a set;
false
does not represent item within a set.

So the aria-current attribute can be used to solve the first use case in this post like this:

Code language: CSS

[aria-current] {
  font-weight: bold;
  background-color: #cc33ff;
}

Code language: HTML

<nav>
  <ul>
    <li><a href="/" aria-current="page">Home</a></li>
    <li><a href="/">About</a></li>
    <li><a href="/">Contact</a></li>
  </ul>
</nav>

When a screen reader encounters the link identified with aria-current, it will announce something like “Home, current page link”.

Whenever aria-current is used with a value other than true, that information is incorporated into the screen reader announcement. For example in this set of steps, a screen reader will announce “Do this, current step link”.

Code language: HTML

<ol>
  <li><a href="/" aria-current="step">Do this</a></li>
  <li><a href="/">Do that</a></li>
  <li><a href="/">Do the other</a></li>
</ol>

The Bias in What We Build

I’ve been thinking a lot lately about our biases and their influence on what we build and how. We’re all biased in some way—it’s an inevitable side-effect of living. We experience certain things, we live in a certain environment, we have certain interactions and over time all of these experiences and factors add up to impact the way we view ourselves and the way we view others.

These biases come into play over and over again in our work, and can have devastating consequences.

There was an interesting post on The Coral Project about anonymity and its impact—or rather, non-impact—on online behavior. A frequent refrain heard when we try to understand why online behavior is so frequently so poor is that the ability to be anonymous is one of the primary reasons for the problem. J. Nathan Matias argues differently, though:

Not only would removing anonymity fail to consistently improve online community behavior – forcing real names in online communities could also increase discrimination and worsen harassment.

We need to change our entire approach to the question. Our concerns about anonymity are overly-simplistic; system design can’t solve social problems without actual social change.

While the article cites a little bit of research questioning our assumptions about anonymity online, the bulk of the article is focused on reframing our perspective of the discussion. We often consider the question of bad behavior online from the perspective of the people misbehaving. What is it that makes them feel free to be so much more vindictive in an online setting? Matias instead builds his case by focusing on the victims of this behavior.

Revealing personal information exposes people to greater levels of harassment and discrimination. While there is no conclusive evidence that displaying names and identities will reliably reduce social problems, many studies have documented the problems it creates. When people’s names and photos are shown on a platform, people who provide a service to them – drivers, hosts, buyers – reject transactions from people of color and charge them more. Revealing marital status on DonorsChoose caused donors give less to students with women teachers, in fields where women were a minority. Gender- and race-based harassment are only possible if people know a person’s gender and/or race, and real names often give strong indications around both of these categories. Requiring people to disclose that information forces those risks upon them.

[…]

[O]ne thing we can state about removing anonymity is that it increases the risk for people on the receiving end of online harassment.

Removing anonymity online, then, is yet another example of how we reflect our own biases in the decisions we make and the things we build.

It is our biases that lead us to overlook accessibility or how an application performs on a low-powered device or spotty network.

It is our biases that lead us to develop algorithms that struggle to recognize women’s voices or show more high-paying executive jobs to men than women.

And it is our biases that lead us to frame the problem of online behavior from that of the attacker, leading to solutions that are dangerous for the people on the receiving end of that harassment.

In each of these situations, our biases don’t just lead us to build something that is hard to use; they cause us to actively, if unintentionally, exclude entire groups of people.

Roving tabindex for keyboard navigation around JavaScript widgets

Setting the tabindex of the focused element to “0” ensures that if the user tabs away from the widget and then returns, the selected item within the group retains focus. Note that updating the tabindex to “0” requires also updating the previously selected item to tabindex="-1". This technique involves programmatically moving focus in response to key events and updating the tabindex to reflect the currently focused item. To do this:

Bind a key down handler to each element in the group, and when an arrow key is used to move to another element:

  1. programmatically apply focus to the new element,
  2. update the tabindex of the focused element to “0”, and
  3. update the tabindex of the previously focused element to “-1”.

Here’s an example of a WAI-ARIA tree view using this technique.

For a more visual explanation, see the following video by Rob Dodson:

Hiding DOM elements - ally.js

This document explains the various ways of hiding things and the implications that come with that.

When we say an element is hidden, we usually mean it is not visible. However, the screen is not the only output mechanism we may need to hide content from. Systems like screen readers and braille displays rely on a document’s representation in the accessibility tree. For disambiguation we’ll use the following terms:

Completely hidden
The element is not rendered on screen, not exposed in the accessibility tree, not accessible to keyboard navigation.
Semantically hidden
The element is rendered on screen, but not exposed in the accessibility tree, and still accessible to keyboard navigation.
Visually hidden
The element is not rendered on screen, but exposed in the accessibility tree, and still accessible to keyboard navigation.

[…]

How to hide elements completely

Completely hiding elements can be done in 3 ways:

  • via the CSS property display, e.g. display: none;
  • via the CSS property visibility, e.g. visibility: hidden;
  • via the HTML5 attribute hidden, e.g. <span hidden>

While each of these techniques has the same end result, i.e. content is not rendered and not exposed in the accessibility tree, they have different behaviors.

[…]

How to hide elements semantically

To hide content from the accessibility tree but retain the content on screen, we may use the attribute aria-hidden="true".

[…]

2016 edition of .visuallyhidden

[…]

Code language: CSS

.visuallyhidden:not(:focus):not(:active) {
  position: absolute;
 
  width: 1px;
  height: 1px;
  margin: -1px;
  border: 0;
  padding: 0;
 
  clip-path: inset(100%);
  clip: rect(0 0 0 0);
  overflow: hidden;
}
  • It works in all modern browsers including Internet Explorer 9 - 11.
  • It side-steps the need to re-style everything for focusable elements such as skip-links.
  • It accounts for the deprecated clip property.

Keyboard navigation

The techniques to hide elements only visually or semantically come with a caveat. Focusable elements like <a href="…"> remain keyboard navigatable, even though the element is not visible on screen or not exposed in the accessibility tree.

To make sure sighted keyboard users do not end up focusing elements they can’t see, and screen reader users not focusing element’s that don’t exist for them, we need to make sure that partially hidden content is not accessible to keyboard navigation using the Tab and Shift Tab keys. To accomplish this, we can add tabindex="-1" to the elements we want to hide from the keyboard.

Recap

  • Use the hidden attribute to completely hide an element.
  • Use the aria-hidden attribute to hide an element from the accessibility tree.
  • Use the .visuallyhidden class to hide an element from the screen.
  • Use visibility: inherit; instead of visibility: visible; to avoid accidentally showing content.
  • Do not attach any CSS styles to the aria-hidden attribute.
  • Take care of keyboard focusable content that is partially hidden by adding tabindex="-1".

Alex Feyerke: Step Off This Hurtling Machine | JSConf.au 2014

I thought this was an excellent talk on the hard questions we should be asking ourselves as developers. Why do most people use closed, proprietary systems and devices, if the open web is so wonderful? Even as developers, we still use them ourselves, and depend on them. How can we be more empathetic to what the average user needs and wants? How can we lock open the web, so the future isn’t entirely dependent on huge corporations and services, which is where we seem to be heading?

You Can't Detect A Touchscreen

Whatever you may think, it currently isn’t possible to reliably detect whether or not the current device has a touchscreen, from within the browser.

And it may be a long time before you can.

Let me explain why…

Boxed in

The browser environment is a sandbox. Your app’s code can only get at things the browser wants you to, in order to limit the damage a malicious website can cause.

This means that the only information about the system you can get is what the browser exposes to you, in the form of HTML, CSS and JavaScript APIs. To determine if a system supports a certain feature, we can a) see if a certain API is present, or b) see if it actually does the right thing.

Historically, two browser features have been used for “touchscreen detection”: media queries and touch APIs. But these are far from foolproof.

Walk with me.

Device width media queries

Mobiles have small screens and mobiles have touchscreens, so small screen equals touchscreen, right?

[…]

So, so very wrong. Large tablets and touchscreen laptops/desktops have clearly proven this wrong. Plus thousands of older mobile handset models had small non-touch screens. Unfortunately, sites applying the mantra “If it’s a small screen, it’s touch; if it’s a big screen, it’s mouse-driven” are now everywhere, leaving tablet and hybrid users with a rubbish experience.

Touch APIs

[…]

If the browser supports events like touchstart (or other events in the Touch Events API spec) it must be a touchscreen device, right?

[…]

Well, maybe. The problem is, no one ever said that a non-touch device can’t implement touch APIs, or at least have the event handlers in the DOM.

Chrome 24.0 shipped with these APIs always-on, so that they could start supporting touchscreens without having separate “touch” and “non-touch” builds. But loads of developers had already used detects like the example above, so it broke a lot of sites. The Chrome team “fixed” this with an update, which only enables touch APIs if a touch-capable input device is detected on start-up.

So we’re all good, right?

Not quite.

An API for an API

The browser is still quite a long way from the device itself. It only has access to the devices via the operating system, which has it’s own APIs for letting the browser know what devices are connected.

While these APIs appear to be fairly reliable for the most part, we recently came across cases whereby they’d give incorrect results in Chrome on Windows 8… they were reporting presence of a touchscreen (“digitizer”), when no touchscreen was connected.

Firefox also does some kind of similar switching and it appears to fail in the same cases as Chrome, so it looks like it might use the same cues – although I can’t profess to know for sure.

It appears certain settings and services can mess with the results these APIs give. I’ve only seen this in Windows 8 so far, but theoretically it could happen on any operating system.

Some versions of BlackBerry OS have also been known to leave the touch APIs permanently enabled on non-touch devices too.

So it looks like the browser doesn’t know with 100% confidence either. If the browser doesn’t know, how can our app know?

Drawing a blank

Assuming the presence of one of these touch APIs did mean the device had a touchscreen… does that mean that if such a touch API isn’t present then there definitely isn’t a touchscreen?

Of course not. The original iPhone (released in 2007) was the first device to support Touch Events, but touchscreens have been around in one form or another since the 1970s. Even recently, Nokia’s Symbian browser didn’t support touch events until version 8.2 was released last year.

IE 10 offers the (arguably superior) Pointer Events API on touch devices instead of the Touch Events spec, so would return false for the ontouchstart test.

[…]

Neither Safari nor Opera has implemented either touch API in their desktop browsers yet, so they’ll draw a blank on touch devices too.

Without dedicated touch APIs, browsers just emulate mouse events… so there are loads of devices kicking about with touchscreens which you simply can’t detect using this kind of detection.

[…]

You’re doing it wrong

In my opinion, if you’re trying to “detect a touchscreen” in the first place, you’re probably making some dangerous assumptions.

[…]

So what should I do?

For layouts, assume everyone has a touchscreen. Mouse users can use large UI controls much more easily than touch users can use small ones. The same goes for hover states.

For events and interactions, assume anyone may have a touchscreen. Implement keyboard, mouse and touch interactions alongside each other, ensuring none block each other.

Front-End Performance Checklist 2017

This is an incredibly exhaustive list of performance tweaks, improvements, and best practices. Some may be outside the scope of smaller websites, but there are plenty of things for everyone.

Back in the day, performance was often a mere afterthought. Often deferred till the very end of the project, it would boil down to minification, concatenation, asset optimization and potentially a few fine adjustments on the server’s config file. Looking back now, things seem to have changed quite significantly.

Performance isn’t just a technical concern: It matters, and when baking it into the workflow, design decisions have to be informed by their performance implications. Performance has to be measured, monitored and refined continually, and the growing complexity of the web poses new challenges that make it hard to keep track of metrics, because metrics will vary significantly depending on the device, browser, protocol, network type and latency (CDNs, ISPs, caches, proxies, firewalls, load balancers and servers all play a role in performance).

So, if we created an overview of all the things we have to keep in mind when improving performance — from the very start of the process until the final release of the website — what would that list look like? Below you’ll find a (hopefully unbiased and objective) front-end performance checklist for 2017 — an overview of the issues you might need to consider to ensure that your response times are fast and your website smooth.

An Intro to Monkey Testing with Gremlins.js

A common idiom in our industry is, “You never can predict how the user will use your product once they get it in their hands.” If you’ve ever watched a stakeholder use a website or web application for the first time, you may know this firsthand. I can’t count the number of times I’ve seen a user seemingly forget how to use websites on a mobile device, or try to use it in a way that makes you think, “But no one would actually do that in real life!”

The thing is, you never really do know what a user may do in the moment. They might be in a frantic state of mind, trying to accomplish something too quickly, and don’t tap or type the way a calm, focused user might. This fits right into the all-too-common scenario of designing and developing for the best case scenario, and not thinking about edge cases or “what happens if things don’t happen perfectly in this order?” As developers, we tend to build things thinking that everything will be understood, that the user is rational and should just know that tapping around too quickly might cause something weird to happen. It can even affect those who might make accidental taps or clicks when not giving an app full attention - how many times have you accidentally tapped on a mobile device when you were walking and talking while also trying to reply to a tweet or email.

Building out tools to help us test the unpredictable aren’t entirely new. In 2012, Netflix had open-sourced their internal service Chaos Monkey, which “terminates virtual machine instances and containers that run inside of your production environment.” In plain language, it’s a service that tears down servers at random to ensure an entire system doesn’t violently collapse during a failure. Our development communities also remind us to not just design for “the happy path”, but how can we actually detect for unpredicted points of failure in our interfaces the way we can with our server architectures?

If a hundred monkeys at typewriters can write the works of Shakespeare, then one monkey should surely be able to find bugs and problems in our interfaces.

Bring in the monkeys

Monkey testing is a method of testing that generates random user input - clicks, swipes, entering input - with the sole purpose of finding issues with, or entirely breaking, your application. Unlike unit and acceptance testing, where you are writing test cases that occur in a specific order or set of conditions, which ultimately creates bias in how your interface is tested. Developers have less control over how a monkey test will execute, and since they are random every time they are run, you’ll never be testing for just one scenario, but rather an infinite combination of interactions.

Although this type of testing is available for most technology stacks, things built for the web haven’t necessarily got there yet. For example, the Android SDK has a UI Exerciser Monkey that handles most interface-level and system-level events. As web developers have begun to think more critically about performance and stress testing, some of these ideas have finally made it over to the world of the web in the form of Gremlins.js, a JavaScript-based monkey testing library written by the team at Marmelab.

Print QR Codes For Easy URL References

Often regarded as an advertising eyesore, QR codes have their place in certain circumstances. One obvious example is providing an easily-scanned sigil on a printed Web page that enables the user to return to the live version without having to type the URL.

Image

To create the matching QR code, we’ll use Google’s Chart API, which has four required components:

  • The kind of chart information we want Google to deliver (qr, in our case);
  • The rendered size of the QR sigil, in pixels;
  • The URL to encode;
  • The form of character encoding to use.

We’d typically associate the URL with a heading element at the top of the page:

Code language: HTML

<header>
<h1>Lizabeth’s Salon</h1>
<h2>Providing Intellectual Stimulation Online Since 2001</h1>
</header>

To create the printed result, we’ll provide a margin on the right side of the h1 that is large enough for the heading, and then position a QR code in that area:

Code language: CSS

header h1 {
   margin-right: 200px;
   margin-bottom: 2rem;
   line-height: 1.5;
}

Because the QR code will be unique to each page, this would be added as an embedded style sheet:

Code language: CSS

@media print {
   header h1:after {
      content: url(https://chart.googleapis.com/chart?cht=qr&chs=150x150&chl=http://yourdomain.com&choe=UTF-8);
      position: absolute;
      right: 0;
      top: 0;
   }
}

This approach has the downside of forcing the developer to enter a URL individually for each page into the API code. If your Web host is running PHP, you can provide the URL of the current page automatically:

Code language: CSS

@media print {
   h1:after {
      content: url(https://chart.googleapis.com/chart?cht=qr&chs=150x150
&chl=http://<?=$_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];?>
&choe=UTF-8);
      position: absolute;
      right: 0;
      top: 0;
   }
}