[uf-discuss] dfn design pattern (proposal)

Fri Aug 17 04:44:27 PDT 2007

This is may be somewhat premature as the results of the assistive 
technology tests aren't back yet:
http://microformats.org/wiki/assistive-technology-abbr-results
But if we do need to look at alternatives to the abbr design pattern, 
one of the ideas that came up in discussion was to use the dfn element.
I've put together a page on the wiki outlining the thinking behind 
this proposal as well as highlighting some of the potential downsides:
http://microformats.org/wiki/dfn-design-pattern
On the plus side, I think it's better not to widen the title design 
pattern to apply to any element (which is essentially what the span 
proposal is saying) so this would only be a slight expansion.
On the down side, the semantics of "defining instance" aren't always 
going to be applicable for datetime, geo, etc. But I think it could 
well cover 80% of use cases.
What's needed:
* Arguments for or against the use of dfn as a container for the 
title design pattern: is this semantic abuse or is it simply 
stretching semantics (like the abbr design pattern).
* Document usage of the dfn element in the wild: I believe it is 
often used in conjunction with the title attribute.
* Test results from screen readers to find out if dfn is treated as a 
special case (like abbr and acronym) or whether it is "safe" to use.
* Feedback from the people building parsers (Mike Kaply, Brian Suda, 
etc.) on whether this would be tricky or easy to implement.
I'm fairly certain that this proposed design pattern would *not* 
cover 100% of use cases but it might cover enough situations to be 
viable as *an alternative* to the abbr design pattern.
Note that I am not suggesting that the abbr deisgn pattern should be 
deprecated. I believe it has its place but I think it would be good 
to provide an alternative to address the accessibility question.
For instance, even if the dfn design pattern is adopted, I will still 
use the abbr element for cases like this:
<abbr class="dtstart" title="2007年08月19日">August 19th</abbr>
That's because I believe exposing the string "2007年08月19日" either to 
sighted or blind users is an acceptable, readable, understandable way 
of formating a date. But for a string like "2007年08月19日T12:39:00" I 
would like to have an alternative that wouldn't directly expose that 
format to the user.
That's my own call, of course. I suspect that others, offered the 
choice of an alternative to abbr, will always go for the alternative. 
And others will choose to always stick with abbr. I think that all of 
those positions should be accommodated.
Look forward to getting your feedback,
Bye,
Jeremy
-- 
Jeremy Keith
a d a c t i o
http://adactio.com/