- From: Robert Burns <rob@robburns.com>
- Date: Fri, 3 Aug 2007 23:06:40 -0500
- To: Robert Burns <rob@robburns.com>
- Cc: Jason White <jason@jasonjgw.net>, public-html@w3.org
- Message-Id: <FF5E3460-0D6E-40B6-91AF-166FF44CF2A0@robburns.com>
On Aug 3, 2007, at 10:06 PM, Robert Burns wrote: > The @type attribute is not always a MIME type. The INPUT and BUTTON > elements both have types that are not MIME types, but simple > classifications just like this proposal. Though deprecated, LI, OL > and UL all had @type attributes unrelated to MIME type, but rather > classification types. Despite being deprecated fo some of these, > the point is there is plenty of historical precedent in HTML for > non-MIME type @type attributes. As for distinguishing between > different equivalent types, I think a @type attribute would be good > (we could also have @contenttype to provide two different ways to > classify the element). Also we have the @title attribute available > on the ALT element to provide human-readable information about the > differences. > > I had earlier suggested a LONGDESC element (ALT, EQUIV, FALLBACK or > LONGDESC all work for me). At least for a one-to-one relation, to > me it makes more sense to use the @lkongdesc attribute from the > original element. To go from primary ---URL---> fallback rather > than referencing from fallback ---IDREF---> primary. Multiple > equivalents could be handled by letting ALT have a content model > that includes an initial ALT or adding a @longdesc attribute to ALT > too. Advantages of this approach include: > > • @longdesc is already supported (backwards compatible) > • @longdesc as a URL instead of an IDREF permits greater author > flexibility (to optimize bandwidth usage and the like) by pointing > @longdesc to either a local '#idref' URL or a remote document URL > • authors can (I guess have to in some sense) express a ranked > preference for equivalents that users and UAs can take into > consideration. One other thing I meant to suggest on this, is that the ALT element could act like a SWITCH (in SVG for example). So an FaLLBACK element (instead of ALT) would contain multiple ALT elements. This way it would be a simple hierarchy between the primary document contents and the alternates. Each ALT could possibly have a @type, a @contenttype and a @title to help a UA and a user select from among the alternates. This FALLBACK element could even be used within an OBJECT element to change the fallback from a hierarchically arranged fallback into shallow hierarchy separating the primary from the alternates. Take care, Rob
Received on Saturday, 4 August 2007 04:42:46 UTC