Anchor tags are regularly used to handle page click events and are accessible by default. Visitors unable to use a mouse, for example, can press the tab key on the keyboard to navigate individual links on a page and can typically press the return/enter key to perform a ‘click’ on a selected anchor link. On some of our sites, however, we show/hide text in response to a mouse click on an accordion div element and not anchor tags which leaves visitors without tab and return/enter key functionality.
This issue was addressed by first copying and renaming a classy field twig template down from core into the custom theme and adding a tabindex=‘0’ attribute to each accordion div item. This sweet attribute and value pair sets the element’s position in the tab order of the page relative to the elements around it. This means that as a user tabs down through the page content the divs get focus in a logical sequence. A simple cache flush and voila! Tabbing functionality complete!