Re: Drop longdesc, get aria-describedat?

On Wed, Mar 7, 2012 at 8:42 PM, Janina Sajka <janina@rednote.net> wrote:
> By way of example Epub has an elaborated requirement:
> http://diagramcenter.org/development/epubdescribedat.html

Have any EPUB implementors indicated they will provide UI for this,
and if so what sort of UI?

I think an HTML spec extension including @longdesc would be
significantly preferable to minting an "interim" epub:describedat
attribute.

Extending HTML5 should not be a problem when EPUB is using a profile
of HTML5 anyway:

    http://idpf.org/epub/30/spec/epub30-contentdocs.html#sec-xhtml

Classing alternative forms of images, such as tactile images, as
"descriptions" is very problematic. For example, it complicates
provision of a UI based on the mere presence of the attribute. The
already introduced "epub:switch" element or the EPUB media type
fallback system might be a better approach for alternative forms of
images:

    http://idpf.org/epub/30/spec/epub30-contentdocs.html#sec-xhtml-content-switch

    http://idpf.org/epub/30/spec/epub30-publications.html#sec-fallback-processing-flow-manifest

While print fidelity might militate against providing default visual
encumbrances for descriptions for images, this cannot hold for video
and audio, so using "a" elements would be preferable to an "interim"
attribute there.

--
Benjamin Hawkes-Lewis

Received on Friday, 9 March 2012 08:08:32 UTC