[SVG2] Clock-value syntax

Hi,

posting to mention a small issue that came up in a user forum:

The Clock-value syntax [1] used e.g for the begin and end attributes  
doesn't quite match the way other numerical values (<number>) are  
parsed[2].

For <number>:

     number ::= wsp* integer ([Ee] integer)?
            | [+-]? [0-9]* "." [0-9]+ ([Ee] integer)? wsp*

For Timecount-val:

     Timecount-val ::= Timecount ("." Fraction)? (Metric)?
     Metric            ::= "h" | "min" | "s" | "ms"
     Fraction          ::= DIGIT+
     Timecount         ::= DIGIT+
     DIGIT             ::= [0-9]

Aligning these would seem like a good thing. This would mean that the  
requirement for having a leading digit is dropped from 'Timecount-val' in  
the grammar, which seems to be a cause of user confusion. Adding support  
for scientific notation seems like a bigger change, but I think the group  
should consider that as well.

Chrome/Opera:
* parses numbers in Timecount-val the same way as <number>

Firefox:
* parses Timecount-val numbers according to the SMIL grammar

IE:
* doesn't support declarative svg animations


[1] https://svgwg.org/svg2-draft/animate.html#ClockValueSyntax
[2] https://svgwg.org/svg2-draft/types.html#DataTypeNumber

-- 
Erik Dahlstrom, Web Technology Developer, Opera Software
Co-Chair, W3C SVG Working Group

Received on Monday, 23 June 2014 11:57:41 UTC