Add explicit language and direction metadata to `AriaNotificationOptions`

[xfq]

Description of bug or feature request

https://www.w3.org/TR/wai-aria-1.3/#ARIANotifyMixin

ariaNotify(announcement, options) can be used to notify people who are blind or have low vision, identifying dynamic changes in the content, but it creates a natural-language string outside normal DOM text content.

The current AriaNotificationOptions only carries priority and does not carry language or string direction. The i18n requirement is that natural-language string fields must have determinable language and direction, preferably from metadata.

Please add explicit language and direction metadata to AriaNotificationOptions. For example:

enum AriaTextDirection { "ltr", "rtl", "auto" };

dictionary AriaNotificationOptions {
  AriaNotifyPriority priority = "normal";
  DOMString lang;
  AriaTextDirection dir = "auto";
};

Authors should provide lang when the announcement language differs from the language of the node or document. They should also provide dir when the string direction is known. And user agents should expose the language and direction metadata to platform accessibility APIs where the platform supports it.

Will this require a change to CORE-AAM?

Will this require a change to the ARIA authoring guide?

[smockle]

Authors should provide lang when the announcement language differs from the language of the node or document.

Can you please share an example of when/why this difference would be desirable?

It’s not clear to me that announcement language should differ from the language of the node or document; consider this from @alisonmaher in #2478 (comment):

…Additionally, if the author is wanting to portray something that would require multiple languages…they should likely indicate that some way in HTML so that it is accessible to AT and non-AT users.…

[smhigley]

To add to what @smockle said, an author could create an otherwise empty element with the desired lang/dir attributes if they needed custom language & direction specifically for the notification that was different from the document or surrounding DOM tree's lang/dir.

I don't believe any of the platform APIs provide a way to define language & direction directly, separate from the referenced DOM node, so I'm also not entirely sure how the suggested metadata would work on a technical level.

[css-meeting-bot]

The ARIA Working Group just discussed Add explicit language and direction metadata to AriaNotificationOptions.

The full IRC log of that discussion

<Zakim> agendum 4 -- -> Add explicit language and direction metadata to AriaNotificationOptions https://github.com//issues/2828 -- taken up [from agendabot]
<Rahim> Clay: I added this to the agenda, ran over in triage last week. Sarah had commented (thanks), and I as well pulling in previous context. Wanted to open it to the ARIA WG to understand the ask, to see if this is something we want/could support. Proposal is to add a lang attribute or action along with ariaNotify calls to designate a different language than the sending element
<Jacques> q+
<Rahim> ...don't see a use case for this, and why we want messages to have arbitrarily different language then sending element and why we would want this
<Rahim> jcraig: You can also modify the lang of the sending element
<spectranaut_> ack Jacques
<Rahim> Clay: There are other options without additional customization
<Daniel> q+
<Rahim> jcraig: Don't agree with the addition of adding a text direction (there's no ARIA text direction property somewhere else is there). We're going to decline this request (don't need it, other ways to do it). Calling this as we consider future expansions, and avoiding ARIA (e.g., should just be text-direction, or dom-text-direction, and not include ARIA)
<spectranaut_> ack Daniel
<Rahim> Daniel: We shouldn't close the issue yet; based on the group's consensus that it's not needed, I would expect the issue to include rationale as to why (e.g., Sarah has explained). We should comment on the alternative ways to do that
<Rahim> spectranaut_: I won't close, I will comment noting if it's enough that there's other ways to do this
<Rahim> zakim, next item