ARIA IDL is changing as part of ARIA PR #2484.
This tool provides new IDL reflection details for impacted ARIA attributes. However, it
only provides simulation for newly enumerated attributes as ARIA content attributes that reflect as
Element? or FrozenArray<Element>? reflect in a simple manner and will be unchanged. The following attributes
have been updated:
aria-atomic
aria-autocomplete
aria-busy
aria-checked
aria-current
aria-disabled
aria-expanded
aria-haspopup
aria-hidden
aria-invalid
aria-live
aria-modal
aria-multiline
aria-multiselectable
aria-orientation
aria-pressed
aria-readonly
aria-required
aria-selected
aria-sort
Many ARIA attributes may also have assistive technology (AT) defaults that are computed
downstream of and separately from a browser's IDL engine. As part of the AT layer (i.e., accessibility tree),
user agents can build the accessibility tree and perform more complex value assignment that isn't possible at the IDL layer (e.g., compute
a default using the element's role which is determined after IDL takes place). This also allows better separation of concerns
so that ARIA IDL reflection can align with HTML's convention for enumerated attributes and JavaScript manipulation of ARIA attributes
is predictable. Examples:
For <div role="alert">, div.ariaAtomic=null
(since the content attribute is missing) although assistive technologies would expose
this element as aria-atomic="true".
For <div role="combobox">, div.ariaHasPopup=null
although assistive technologies would expose this element as though aria-haspopup="listbox".