For quite a few components on the web, there is an accessible way to implement them. For tabs, it’s a little more complicated. With a few attributes, however, we can get pretty close.
The elements for tabs are very simple. Just an unordered list, links, and
<ul> <li><a id="tab-1" href="#tab-1">Tab 1</a></li> <li><a id="tab-2" href="#tab-2">Tab 2</a></li> <li><a id="tab-3" href="#tab-3">Tab 3</a></li> </ul> <div id="tab-1-panel"></div> <div id="tab-2-panel"></div> <div id="tab-3-panel"></div>
div at the proper time, this is all that’s needed to get tabs working for sighted users. Unfortunately, this is where many stop. However, vast improvements can be made with a few attributes, starting with
For the unordered list and links, there are
tab roles. In addition, each list item gets a role of
presentation to remove semantic meaning.
<ul role="tablist"> <li role="presentation"> <a id="tab-1" href="tab-1" role="tab">Tab 1</a> </li> ...
div, there is the
<div id="tab-1" role="tabpanel"></div>
With this, there is a
tab for each
tabpanel, which begins to create a link between two elements that are otherwise unrelated.
Next, in a similar way, there are
aria-* attributes that need to be added to tabs and tab panels. Going back to the tab list, there is an
aria-controls attribute that points to the
id of its corresponding tab panel.
<ul role="tablist"> <li role="presentation"> <a id="tab-1" href="tab-1" role="tab" aria-controls="tab-1-panel">Tab 1</a> </li> ...
tabpanel, there is a corresponding attribute that goes with
aria-controls. This is the
aria-labelledby attribute, which needs to be added to each tab panel. The value of the attribute is the
id of the corresponding tab.
<div id="tab-1" role="tabpanel" aria-labelledby="tab-1"></div>
At this point, we established the proper identity of all the elements we wish to represent tabs. The last piece of this is to communicate the current state of the tabs. We need to communicate to the user which tab is currently selected, and accordingly, which tab panel is currently visible.
On each tab, there is
true, and the rest remain
<ul role="tablist"> <li role="presentation"> <a id="tab-1" href="tab-1" role="tab" aria-controls="tab-1-panel" aria-selected="true">Tab 1</a> </li> ...
Again, much like the
roles and other ARIA attributes, there is a corresponding attribute for the tab panels. This one is slightly different, which is confusing at first. Each tab panel needs an
aria-hidden attribute, which is set to
true by default, and
false on the currently active tab. It’s the reverse of the
aria-selected attribute on the tabs, so this tripped me up.
<div id="tab-1" role="tabpanel" aria-labelledby="tab-1" aria-hidden="false"></div>
aria-selected set to
true, and the corresponding tab panel needs to have
aria-hidden set to