(Navigation) Landmark Discoverability
I want to talk about some great advice tweeted by @heydonworks:
#a11y tip: Your menu button should be placed _within_ your <nav>, so it's still reachable by landmark navigation. pic.twitter.com/rRzoFzKOOI— Heydon (@heydonworks) August 20, 2016
The placement of the button is key, and the persistent availability of the navigation element, and thus the landmark it exposes is very important.
However, discussing this more with others, and seeing the responses to the tweet, it was apparent that there quite a few who did not understand the significance of the example, and why placing the button inside the navigation landmark was important.
Discoverability is key
What people were primarily focusing on was the button’s placement and how that would affect the design, the way they’d need to code the CSS to target the navigation’s
<ul> instead of the
<nav> itself. Why couldn’t they just put the button somewhere else in the DOM and use
aria-controls to point to the navigation?
To all of that I’d respond…
The issue is that correctly hiding a navigation by default, whether that be done with
display: none or
visibility: hidden, not only removes it visually from view, but also removes it from being discovered by assistive technologies (ATs), e.g., screen readers.
You see, users of ATs don’t just start feverishly tabbing through an interfaces just hoping to find what it is they’re looking for. Well. Maybe they would if they were trying to prove a point about how horrible a site was coded. But yeah. Not really.
Typically when an AT user comes to a page, they do what sighted users do. They do a quick scan of the page. Obviously their method of doing so is different. While sighted users can quickly just look around a page and determine functionality and relationships by appearance, a fundamental way for AT users to determine a site’s structure and significance is by its structural makeup, such as what landmarks (topical!) and headings are available (There are other methods as well, but let’s just stay on topic).
Looping back to the hidden navigation, this is where the problem arises and Heydon’s example is the solution.
<nav> removes it from the landmark listing. So AT users would come to the page and on initial review could only determine “Oh. This page doesn’t have a designated navigation region. Well. This should be fun…”
It’s not that the navigation couldn’t or wouldn’t eventually be discovered. The issue is that there would be no easy access to it. A user would have to learn that the element to open the navigation was in a particular location in the DOM. Remember that location. Navigate to and through that location as necessary. Activate the element to expose the navigation, and then they would finally be able to enter it and access the necessary content within.
By placing the button to reveal the navigation within the navigation landmark, and instead hiding the rest of the navigation’s contents (whether that be the primary list element or a
<div>s surrounding multiple components of the navigation), the navigation never gets hidden from ATs</code> and can be easier to discover.
<nav> <!-- the landmark is always exposed and it's the listing of links within that has its display toggled. --> <button aria-expanded=false> Reveal navigation </button> <ul syle="display: none"> ... </ul> </nav>
So what are the takeaways here?
Mainly, this is more about being mindful with how our documents are setup and what we reveal (or don’t) to all users with our document structure and CSS.
aria-expanded to communicate whether the content is displayed (expanded) or hidden (collapsed).
The high level intent may be to visually hide a navigation from view, until a user specifically wants to interact with it. But the overall intent is likely not to obscure the fact that a navigation exists. I mean, sighted users can see the navigation toggle button, and understand that this will show/hide a navigation per its common visual design. This same affordance needs to be provided to users of assistive technology. If all one has to go off is the way this control is aurally exposed to them, then the mention of the navigation role is important to distinguish this from some other random toggle button that could appear on the page.