Jamie: The key point is that ARIA-Details is a better and more capable longdesc.
It's better because it utilizes an approach browsers support, and most specifically, one they don't vehemently oppose. It's more capable because it can be applied on any element. So, as an example, we once again have a mechanism for a publisher to provide an overview of a complex table, rather than requiring a user to navigate the table and figure out cell by cell what the table does. The overview is the first impact a sighted user has from seeing a table, but the screen reader user would have to go cell by cell to figure out basic structure. Just an example. The UI should be the same as for longdesc. Once properly supported by the browsers, it is expected to provide the same kind of interface via the underlying browser engine, e.g. Webkit and Gecko. hth Janina Richard Schwerdtfeger writes: > >I've already stated my view on this and asked several questions, but > it seems key decisions have already been made, despite a lack of > clarification around the concerns I've raised. >Given that this has > basically become a circular time sink of an argument, I'll provide a > final summary of my thoughts. > >1. With regard to stringification, I still haven't seen a single solid > justification for why errormessage and details are different to > description from a user perspective. It's been argued that >users > should be able to get to the content and read it in its full semantic > glory, but no one has pointed out a use case for why that is actually > necessary for, say, an error message. Surely, >the desired UX for a > screen reader is that it should read the error message when it appears, > not force the user to press some key to jump there and review it. If we > want to read the >message, we need to stringify it... and crawling the > tree to stringify it ourselves is going to be a hideous perf problem. > > James, > > I appreciate your willingness to work with us on this. However, let me > provide you with the full picture. > > 1. Extended descriptions, referenced by aria-details was requested by > the digital publishing industry. The extended description can have all > kinds of markup in it and not just HTML: ChemML, MathML, SVG drawings, > etc. It is intended as an extended, and sometimes alternative content > to better illustrate what is being referenced. For these reasons it is > essential that we *always* preserve content. In fact the > stringification in many cases could be completely useless to a screen > reader user. Also, for these reasons the intent is for it to be visible > and not hidden as aria-describedby often is as it must be accessible to > all users and not just the blind. Furthermore, there will be instances > where the content will be contained within an IFrame within a > details/summary element. The big thing here is stringification is > simply the wrong thing to do and it must not happen in the browsers for > extended descriptions. > > The second thing you need to understand is the aria-details attribute > was created after months of fighting between browser vendors and people > in the accessibility community over longdesc. We don't want to open up > that pandora's box again. This is the solution that has come to place. > aria-describedby simply does not meet the needs of digital publishing > community. What is more they plan to support it in their digital books > once a mechanism is put in place, within browsers, to show and hide > content reference by aria-details in order to preserve the needs of > publishers who don't want extended descriptions rendered by default. We > definitely, don't want this functionality applied to aria-describedby. > > >2. Having errormessage/details as completely separate concepts from > description means an AT now has two more things it has to fetch for > *every single object that gets focus*. This is >yet another perf > problem. > > Error messages are not the same as extended descriptions and we don't > want the same functionality to duplicated with error messages as I > described above. The need for error messages arose many major companies > rendering visible, popup, error messages for each invalid form entry. > They want to have people with disabilities get access to each error > messages associated with the invalid control and they want to also have > access to the hidden aria-describedby help information they provide for > that control. So, stomping on one in favor of the other is a very bad > experience. They are indeed distinct and separate concepts. > >3. That said, since the no description/no stringification decision has > already been made (despite the concerns above which I raised months > ago), relations is the only mapping that >doesn't violate the spec. > > See above. I hope I have addressed most of your concerns. > >4. Since we're not stringifying as part of description, it does not > make sense to map these to the describedBy relation. Thus, we need two > new relations. > > ok > >5. Reverse relations may well be useful in the future. However, if > they're a potential perf problem, I agree it makes sense to wait until > we have a use case, so long as implementers accept >that this use case > may one day arise. > Joanie Diggs asked for reverse relationships as she wants to be able to > traverse back to the source. She is on CC and will be back from > vacation next week. > > Best, > Rich > Rich Schwerdtfeger > > > ----- Original message ----- > From: James Teh <ja...@nvaccess.org> > To: Richard Schwerdtfeger/Austin/IBM@IBMUS, > surkov.alexan...@gmail.com > Cc: accessibility-ia2@lists.linuxfoundation.org, jdi...@igalia.com > Subject: Re: aria-details and aria-errormessage mapping > Date: Thu, Aug 18, 2016 9:45 PM > > Hi. > > > I've already stated my view on this and asked several questions, but > it seems key decisions have already been made, despite a lack of > clarification around the concerns I've raised. Given that this has > basically become a circular time sink of an argument, I'll provide a > final summary of my thoughts. > 1. With regard to stringification, I still haven't seen a single > solid justification for why errormessage and details are different > to description from a user perspective. It's been argued that users > should be able to get to the content and read it in its full > semantic glory, but no one has pointed out a use case for why that > is actually necessary for, say, an error message. Surely, the > desired UX for a screen reader is that it should read the error > message when it appears, not force the user to press some key to > jump there and review it. If we want to read the message, we need to > stringify it... and crawling the tree to stringify it ourselves is > going to be a hideous perf problem. > 2. Having errormessage/details as completely separate concepts from > description means an AT now has two more things it has to fetch for > *every single object that gets focus*. This is yet another perf > problem. > 3. That said, since the no description/no stringification decision > has already been made (despite the concerns above which I raised > months ago), relations is the only mapping that doesn't violate the > spec. > 4. Since we're not stringifying as part of description, it does not > make sense to map these to the describedBy relation. Thus, we need > two new relations. > 5. Reverse relations may well be useful in the future. However, if > they're a potential perf problem, I agree it makes sense to wait > until we have a use case, so long as implementers accept that this > use case may one day arise. > Thanks, > Jamie > > On 19/08/2016 7:21 AM, Richard Schwerdtfeger wrote: > > We *cannot* map aria-errormessage or aria-details to a string > description. That is absolutely prohibited in the aria specification. > It is not to be stringified. Neither is aria-details. Also, in the aria > spec. if aria-details and aria-describedby cannot be mapped separately > aria-details takes precedence. > > These are intended to be references so that we can also get access to > the structural markup. > > Now, if you are going to overload the description relationships we need > something on the target that indicates they are an error or an extended > description. We need to have the distinctions. Object attributes are an > option. > > Rich > > Rich Schwerdtfeger > > > ----- Original message ----- > From: Alexander Surkov [1]<surkov.alexan...@gmail.com> > To: Richard Schwerdtfeger/Austin/IBM@IBMUS > Cc: [2]"accessibility-ia2@lists.linuxfoundation.org" > [3]<accessibility-ia2@lists.linuxfoundation.org>, James Teh > [4]<ja...@nvaccess.org>, Joanmarie Diggs [5]<jdi...@igalia.com> > Subject: Re: aria-details and aria-errormessage mapping > Date: Fri, Aug 12, 2016 7:42 PM > > I'd love to hear Jamie on this honestly, but his wording was: > " > To me, it sounds like errormessage just makes the rules slightly simply > to make life simpler for authors; errormessage isn't presented unless > invalid is true, errormessage must be visible to be presented, etc. > That > might be fair enough. However, that doesn't mean it's an entirely > fundamentally separate concept, and thus, there's a good argument for > mapping it to description in a11y APIs (with appropriate rules)." > Do we a real example/scenario where AT has to know that a message on > the screen is an error message, and this knowledge would improve the > user experience? > > > On Wed, Aug 10, 2016 at 3:45 PM, Richard Schwerdtfeger > <[6]sch...@us.ibm.com> wrote: > > Yes, we heard. So, we need to be able to differentiate an associated > error message from a help descriptions. So, you could have a second > aria-details relationship in the list of relationships as it would not > be stringified (a necessity), BUT you would need to put something on > the target ID container to indicate to the AT that it is an error > message. Otherwise you need a different relationship. If you are not > having reverse relationships and AT vendors would provide a mechanism > to go back to the element that was invalid then you would be fine. The > use cases we have seen in practices is that multiple form elements > become invalid and each has an associated popup error message. > > We cannot mix descriptions and error messages and the error messages > must be visible to all users to be mapped. > > Rich > > Rich Schwerdtfeger > > > ----- Original message ----- > From: Alexander Surkov <[7]surkov.alexan...@gmail.com> > > To: Richard Schwerdtfeger/Austin/IBM@IBMUS > Cc: "[8]accessibility-ia2@lists.linuxfoundation.org" > <[9]accessibility-ia2@lists.linuxfoundation.org>, James Teh > <[10]ja...@nvaccess.org>, Joanmarie Diggs <[11]jdi...@igalia.com> > Subject: Re: aria-details and aria-errormessage mapping > Date: Wed, Aug 10, 2016 12:48 PM > > Note, Jamie has been objecting against new relation for > aria-errormessage [1]. > [1] [12]https://lists.linuxfoundation.org/pipermail/accessibility- > ia2/2016-April/002046.html > > On Wed, Aug 10, 2016 at 8:33 AM, Alexander Surkov > <[13]surkov.alexan...@gmail.com> wrote: > > All reverse relations go at performance/memory cost, I would introduce > them iff AT needs them. I'm not sure I see a valid scenario, when they > were useful, thus deferring a decision to Joanie and Jamie, who knows > more about AT internal gear than me. > > > On Tue, Aug 9, 2016 at 4:58 PM, Richard Schwerdtfeger > <[14]sch...@us.ibm.com> wrote: > > Those would be great. What would you have for reverse relationships? > > Rich Schwerdtfeger > > > ----- Original message ----- > From: Alexander Surkov <[15]surkov.alexan...@gmail.com> > To: "[16]accessibility-ia2@lists.linuxfoundation.org" > <[17]accessibility-ia2@lists.linuxfoundation.org>, James Teh > <[18]ja...@nvaccess.org>, Joanmarie Diggs <[19]jdi...@igalia.com>, > Richard Schwerdtfeger/Austin/IBM@IBMUS > Cc: > Subject: aria-details and aria-errormessage mapping > Date: Tue, Aug 9, 2016 2:12 PM > > Hi. > ARIA 1.1 got two relation-like attributes: aria-details [1] and > aria-errormessage [2], used to connect an element with content > providing extra info. Rich mentioned that these attributes are likely > need new IAccessible2 relations to expose them, which sounds > reasonable. If that's the case, then we should end up with something > like: > > An object containing details for the target object. > IA2_RELATION_DETAILS > An object containing an error message for the target object. > IA2_RELATION_ERROR_MESSAGE > Thanks. > Alex. > [1] [20]https://www.w3.org/TR/wai-aria-1.1/#aria-details > [2] [21]https://www.w3.org/TR/wai-aria-1.1/#aria-errormessage > > > > > > -- > James Teh > Executive Director, NV Access Limited > Ph +61 7 3149 3306 > [22]www.nvaccess.org > Facebook: [23]http://www.facebook.com/NVAccess > Twitter: @NVAccess > SIP: [24]ja...@nvaccess.org > > References > > 1. mailto:surkov.alexan...@gmail.com > 2. mailto:accessibility-ia2@lists.linuxfoundation.org > 3. mailto:accessibility-ia2@lists.linuxfoundation.org > 4. mailto:ja...@nvaccess.org > 5. mailto:jdi...@igalia.com > 6. mailto:sch...@us.ibm.com > 7. mailto:surkov.alexan...@gmail.com > 8. mailto:accessibility-ia2@lists.linuxfoundation.org > 9. mailto:accessibility-ia2@lists.linuxfoundation.org > 10. mailto:ja...@nvaccess.org > 11. mailto:jdi...@igalia.com > 12. > https://lists.linuxfoundation.org/pipermail/accessibility-ia2/2016-April/002046.html > 13. mailto:surkov.alexan...@gmail.com > 14. mailto:sch...@us.ibm.com > 15. mailto:surkov.alexan...@gmail.com > 16. mailto:accessibility-ia2@lists.linuxfoundation.org > 17. mailto:accessibility-ia2@lists.linuxfoundation.org > 18. mailto:ja...@nvaccess.org > 19. mailto:jdi...@igalia.com > 20. https://www.w3.org/TR/wai-aria-1.1/#aria-details > 21. https://www.w3.org/TR/wai-aria-1.1/#aria-errormessage > 22. http://www.nvaccess.org/ > 23. http://www.facebook.com/NVAccess > 24. mailto:ja...@nvaccess.org > _______________________________________________ > Accessibility-ia2 mailing list > Accessibility-ia2@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/accessibility-ia2 -- Janina Sajka, Phone: +1.443.300.2200 sip:jan...@asterisk.rednote.net Email: jan...@rednote.net Linux Foundation Fellow Executive Chair, Accessibility Workgroup: http://a11y.org The World Wide Web Consortium (W3C), Web Accessibility Initiative (WAI) Chair, Accessible Platform Architectures http://www.w3.org/wai/apa _______________________________________________ Accessibility-ia2 mailing list Accessibility-ia2@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/accessibility-ia2
