All `ElementInternals` docs for `ARIAMixin` properties are incorrect

MDN URL

https://developer.mozilla.org/en-US/docs/Web/API/ElementInternals

What specific section or headline is this issue about?

Instance properties included from ARIA

What information was incorrect, unhelpful, or incomplete?

The issue I am reporting isn’t just for the page I’ve reported the issue for, but for all of the linked pages in the noted section as well.

ARIAMixin properties are implemented differently for ElementInternals than they are for Element, however, the docs describe them how they work for Element (i.e. as reflecting content attributes). For ElementInternals the properties set default semantics or “implicit ARIA” for the element. There are a number of notes that correctly point that out, but the main content remains incorrect.

Some examples, starting with the ElementsInternals page:

ElementInternals.ariaAtomic A string reflecting the aria-atomic attribute, which indicates whether assistive technologies will present all, or only parts of, the changed region based on the change notifications defined by the aria-relevant attribute.

From the “ElementInternals: role property” page:

The role read-only property of the ElementInternals interface returns the WAI-ARIA role for the element. For example, a checkbox might have role="checkbox". It reflects the role attribute; it does not return the element's implicit ARIA role, if any, unless explicitly set.

What did you expect to see?

The docs should correctly describe how ARIAMixin properties for ElementInternals work: that they don’t reflect any attributes, but rather represent the default semantics of the custom element.

Do you have any supporting links, references, or citations?

Relevant spec work (that does not describe how ARIAMixin should work for ElementInternals):

• https://html.spec.whatwg.org/multipage/custom-elements.html#elementinternals
• https://w3c.github.io/aria/#ARIAMixin

The AOM explainer describes how ElementInternals works and notes that they do not reflect.

Do you have anything more you want to share?

No response

MDN metadata

• Folder: en-us/web/api/elementinternals
• MDN URL: https://developer.mozilla.org/en-US/docs/Web/API/ElementInternals
• GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/web/api/elementinternals/index.md
• Last commit: https://github.com/mdn/content/commit/8b920a5e7567dcc9d642dfbd704b0ddbe2005d30
• Document last modified: 2024-07-27T01:21:26.000Z