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

Simon Pieters simonp at opera.com
Sun Jun 21 23:31:54 PDT 2009

On Sat, 20 Jun 2009 18:34:38 +0200, Smylers <Smylers at stripey.com> 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

Maybe the spec should remove these feature strings altogether and  
encourage authors to use more accurate methods of detecting support.

Simon Pieters
Opera Software

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