Examples of Included in the accessibility tree
These are examples of the Included in the accessibility tree definition. The examples presented here are non-normative and not testable. They serve to illustrate some common pitfalls about the definition and to help implementers of ACT rules understand it.
Default inclusion
This h3
element is included in the accessibility tree (by default, elements are included in the accessibility tree).
<h3>ACT rulesh3>
Removed with CSS display
This h3
element is not included in the accessibility tree because it is hidden to everybody by the CSS property.
<h3 style="display:none">ACT rulesh3>
Removed with aria-hidden
This h3
element is not included in the accessibility tree because it is explicitly removed by the aria-hidden
attribute.
<h3 aria-hidden="true">ACT rulesh3>
Included but off screen
This h3
element is positioned off screen, hence is not visible, but is nonetheless included in the accessibility tree.
<h3 style="position: absolute; top:-9999em">ACT rulesh3>
Removed but not ignored
Although this h2
element with an id
of "label" is not itself included in the accessibility tree, it still provides an accessible name to the h3
via the aria-labelledby
attribute. Thus, it is still indirectly exposed to users of assistive technologies. Removing an element from the accessibility tree is not enough to remove all accessibility concerns from it since it can still be indirectly exposed.
<h2 id="label" style="display:none">ACT rulesh2>
<h3 aria-labelledby="label">Accessibility Conformance Testing rulesh3>
Removed but focusable
Although this input
element is not included in the accessibility tree, it is still focusable, hence users of assistive technologies can still interact with it by sequential keyboard navigation. This may result in confusing situations for such users (and is in direct violation of the fourth rule of ARIA (working draft)).
<span aria-hidden="true">
<input type="text" name="fname" />
span>