Allow aria-flowto to have multiple ID references

[Zhang-Junzhi]

Description of bug or feature request

Document reading order doesn't have to be "nearly one dimensional"(where almost every information piece flows into only one next information piece), instead, it is absolutely possible to be "highly two dimensional".

For example, consider if I am writing a page showing a large mind tree, where reading order is highly flexible. In the mind-tree document, almost every text block connects to multiple next text blocks, making the document reading order "highly two-dimensional".

Nowadays, WEB tech has evolved so far, it's becoming more and more practical to let document contents have various flexible reading orders. So please consider allowing aria-flowto to have multiple ID references.

[pkra]

The conclusion of this thread (from 2022) is relevant #630 (comment)

The ARIA WG agreed to NOT deprecate aria-flowto until a suitable replacement arises.

An expansion of aria-flowto seems unlikely unless support has improved.

[MarioBatusic]

Hi all people with good contacts to AT developers! Could you please try to convince them to improve the use of aria-flowto? It could be very useful tool e.g. for screen reader users especially if it could be extended to show to more than one target.

[spectranaut]

Deep dive for discussion of particular use case and priority of fix.

[spectranaut]

Discussed during triage in today's meeting: https://www.w3.org/2024/03/14-aria-minutes.html

@Zhang-Junzhi, for some extra context, aria-flowto has extremely mixed support in browsers and screen readers, so extending the feature is not really possible. However, the inability to support use cases like mind maps is a concern and we will discuss how to prioritize that work. The solution might be totally different than aria-flowto.

[Zhang-Junzhi]

Discussed during triage in today's meeting: https://www.w3.org/2024/03/14-aria-minutes.html

@Zhang-Junzhi, for some extra context, aria-flowto has extremely mixed support in browsers and screen readers, so extending the feature is not really possible. However, the inability to support use cases like mind maps is a concern and we will discuss how to prioritize that work. The solution might be totally different than aria-flowto.

Thank you for your work.