[whatwg] hasFeature() When Only 1 Syntax is Supported

[Ian Hickson]

On Sat, 20 Jun 2009, Smylers wrote:
>
> The current text suggests that a user-agent may choose to support only 
> the HTML syntax (not XHTML) but should still return true for 
> hasFeature("XHTML", "5.0").
> 
> If that isn't intended then the requirements for hasFeature() should be
> changed to depend on the syntaxes chosen to be implemented.  If it _is_
> intended (and given various things browsers have to do for web
> compatibility, it wouldn't surprise me) then perhaps it would be better
> to spell this out explicitly, since it's counter-intuitive.
> 
> hasFeature() currently has the implementation requirements:
> 
>   User agents should respond with a true value when the hasFeature
>   method is queried with these values.
> 
>     -- http://www.whatwg.org/html5#dom-feature-strings:
> 
> Where "these values" are ("HTML", "5.0") and ("XHTML", "5.0").
> 
> However while supporting both HTML and XHTML is "encouraged",
> user-agents "may" choose to support only one of them:
> 
>   http://www.whatwg.org/html5#conformance-requirements

On Mon, 22 Jun 2009, Simon Pieters wrote:
> 
> Maybe the spec should remove these feature strings altogether and 
> encourage authors to use more accurate methods of detecting support.

On Wed, 24 Jun 2009, Simon Pieters wrote:
> 
> The spec is now gaining all the remaining stuff from DOM2 HTML, so this 
> note is incorrect:
> 
> "Note: The interfaces defined in this specification are not always 
> supersets of the interfaces defined in DOM2 HTML; some features that 
> were formerly deprecated, poorly supported, rarely used or considered 
> unnecessary have been removed. Therefore it is not guaranteed that an 
> implementation that supports "HTML" "5.0" also supports "HTML" "2.0"."
> 
> I'm thinking that the spec should maybe just use "2.0" instead of "5.0", 
> since it's what browsers do and there might be pages that check for 
> this.
> 
> Meanwhile it seems useful to return false as appropriate if the UA only 
> allows one of the syntaxes, as Smylers points out.

I've removed everything but HTML/2.0.

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'