[whatwg] Features in XForms Tiny that Web Forms 2 lacks

[Anne van Kesteren]

I went through the examples on http://www.w3.org/2006/11/XForms-Tiny/ to  
find out which features "XForms Tiny" has that Web Forms 2 currently does  
not have. I'm not sure how these features are supposed to be implemented  
(saying this up front as Hixie already had a few interesting questions in  
#webapi). This list might not be complete.

A calculate="" attribute which takes an ECMAScript expression which  
evaluates to a value for the form control.

A constraint="" attribute which takes an ECMAScript expression which  
evaluates to a boolean which determines whether or not the control is  
valid.

A needed="" attribute which takes an ECMAScript expression which evaluates  
to a boolean which determines whether or not the control is required.  
(This basically allows more than than the current required="" attribute in  
the Web Forms 2 specification.)

A relevant="" attribute which takes an ECMAScript expression which  
evaluates to a boolean which determines whether the control is "relevant".  
This attribute also applies to <fieldset> elements.

If you have a repeated set of form controls there's a way to associate a  
single label with the "same" control in each set of form controls which  
you can then style based on one or more of the form controls in the  
repeated set of form controls being invalid (or not meeting another  
condition I presume). See  
http://www.w3.org/2006/11/XForms-Tiny/17/Overview.html for instance.

http://www.w3.org/2006/11/XForms-Tiny/14/Overview.html is also an  
interesting one. I'm not sure how to summarize its functionality though.


-- 
Anne van Kesteren
<http://annevankesteren.nl/>
<http://www.opera.com/>