- From: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
- Date: Thu, 28 Nov 2013 21:12:18 +0100
- To: Loretta Guarino Reid <lorettaguarino@google.com>
- Cc: Steve Faulkner <faulkner.steve@gmail.com>, "Schnabel, Stefan" <stefan.schnabel@sap.com>, Michael Cooper <cooper@w3.org>, David MacDonald <david100@sympatico.ca>, Janina Sajka <janina@rednote.net>, HTML Accessibility Task Force <public-html-a11y@w3.org>, WCAG WG <w3c-wai-gl@w3.org>, "public-comments-wcag20@w3.org" <public-comments-wcag20@w3.org>, Gregg Vanderheiden <gv@trace.wisc.edu>, "kirsten@can-adapt.com" <kirsten@can-adapt.com>
Loretta Guarino Reid, Thu, 28 Nov 2013 11:02:54 -0800: > I disagree. This is an example of using text already on the page as the > image description. Agreed. > This is not an attempt to use aria-labelled by as an > alternate implementation of alt. From the most literal perspective, you are right. Because, after all, the example uses aria-labelLEDBY - and not aria-label. However, semantically, aria-label and aria-labelledby are equivalents. They only differ in where they take the label text from: One is a label container, the other points to the label container(s). Therefore, from a semantic perspective, you are wrong: It doesn't matter whether you use aria-label or aria-labelledby. From this semantic view, it makes perfect sense that aria-labelledby does not prevent redundancy. > It is a use case where alt is redundant if > the image description is already present and can be associated with the > image via aria-labelledby. Avoid redundancy is precisely the role of aria-hidden="true" - that's why I added it on the <p> element. What we are looking for is a *programmatic* association of image and text.[0][1][2] In HTML5, the use of <figure> plus <figcaption> provides such an association, without use of aria-labelledby. That's why HTML5 allows @alt to be omitted on <img> when it occurs inside <figure> with a <figcaption>. If you were to replace <figure> with a <div>, you would need to use aria-labelledby in order to programmatically associate a child <span id=label> element with the img. But then you would also get that redundancy problem. PS: The aria-labelledby can point to more than one element. And in such a situation, it might make perfect sense to *not* use aria-hidden="true" to hide the adjacent element *even if* it this means that *one* part label (namely the text of the adjacent element) is repeated. [0] http://www.w3.org/TR/WCAG-TECHS/F65.html#F65-applicability [1] http://www.w3.org/TR/2008/REC-WCAG20-20081211/#text-equiv-all [2] http://www.w3.org/TR/2008/REC-WCAG20-20081211/#text-altdef Leif H Silli > On Thu, Nov 28, 2013 at 9:51 AM, Leif H. Silli wrote: > >> Loretta Guarino Reid, 28.11.2013, 17:45 >> >>> Adding aria-hidden completely changes this example, which is one where >> the >>> image description is already available as *visible* text. This is a >> similar >>> use case to figure and figcaption. >> >> Well, it is the aria-labelledby that “completely changes" the example. >> Aria-hidden merely deals with the effect of the aria-labelledby. >> >> Leif Halvard Silli >> >>
Received on Thursday, 28 November 2013 20:12:56 UTC