[whatwg] Markup for Web Forms 2.0 that still requires discussion

[Matthew Raymond]

Ian Hickson wrote:
> The point is that you _don't_ want it to be ignored. You want it to be
> ignored on WF2 UAs, and not in legacy UAs.
> 
> So effectively it's a "conditional comment", except that the condition is
> "supports the <ignore> element" (or attribute, whichever).
> 
> It is basically equivalent to <legacy value="Web Forms 2.0">. See:
> 
>    http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2004-July/000839.html

    Okay, how about a slightly different solution:

<input type="text" id="combo1" name="combo1" list="myList" />
<fallback id="combo1" attrib="list">
   <label for="myList"> or select from the list: </label>
   <select id="myList" name="combo1">
     <option>Item One</option>
     <option>Item Two</option>
     <option>Item Three</option>
   </select>
</fallback>

    The <fallback> element would only render when the "list" attribute 
for element "combo1" is not correctly processed by the user agent. It 
would of course render when the |list| attribute isn't supported on the 
system, but it would also render if |list| had an invalid value. If the 
element referenced by |id| is itself unsupported, <fallback> will render 
in that situation as well.

    Any UA implementing <fallback> need not provide a mechanism for what 
standards it supports. It need only verify that it could not process a 
specific element and/or attribute. In this way, the user doesn't even 
have to know what standard the element or attribute belongs to.

    Is this sufficient?