[whatwg] 2.2.1. DOM feature strings

Anne van Kesteren fora at annevankesteren.nl
Mon Nov 7 07:44:48 PST 2005

Quoting ROBO Design <robodesign at gmail.com>:
> a)
>> User agents should respond with a true value when the hasFeature
>> method is queried with these values.
> Why the word "should" is being used? This allows implementors to 
> simply  not implement this, therefore not providing authors a way to 
> check for  HTML 5 support (WA 1.0).

Nobody in his right mind would use hasFeature to check for support. It 
is merely
there for compatibility and joy.

> b) The feature string "XHTML" combined with version string "5.0" is 
> to me  not very inspired. Simple reason: XHTML 2. What if they get to 
> XHTML 5? In  my opinion, checking for XHTML 5.0 should *not* be 
> available.

How else can you check if XHTML support is on? Furthermore, XHTML 2 does not
define DOM interfaces so that should not be a problem. (They're not 
planning to
do so either.)

> c) hasFeature("WA", "1.0") should be also available, because the  
> specification defines Web Applications 1.0 (aka HTML 5).

Neh. If all goes well the specification will eventually be called HTML 5.

> d)
>> in general, therefore, use of this method is discouraged.
> How are authors supposed to check for WA 1.0 support in the user 
> agent? I  agree that user agents are not perfect and therefore they 
> might return  true (or false) even if they do (not) support WA 1.0.

Incremental innovation. How do you check which user agent supports 
How do you check which user agent supports the CSS color value "orange"? You



Anne van Kesteren

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