Re: [SVGMobile12] SVGT12-207: No conformance criteria for how to parse attribute values

On Thu, 22 Dec 2005, Robin Berjon wrote:
> > > >
> > > > How should multiple commas in a row be parsed?
> > > 
> > > Please see the following line of the EBNF
> > > 
> > > comma-wsp:
> > >     (wsp+ comma? wsp*) | (comma wsp*)
> > 
> > This says that multiple commas don't match the grammar, it doesn't say 
> > how to handle them if they are there. (However, if it is the 
> > intention, as noted below, that rendering UAs should include 
> > conformance checkers, then I accept that the processing of multiple 
> > commas is defined.)
> 
> Generally the error handling is specified on the attributes, not on the 
> data types. Unless otherwise noted, when an attribute holds a value that 
> is incorrect it is treated as if it hadn't been specified. The behaviour 
> then depends on what the default value is.

So to clarify, it is indeed expected that, e.g. mobile phone vendors, will 
implement conformance checkers for attribute values?

If so, please ensure that this is tested carefully by the SVG 1.2 Tiny 
test suite before any claim regarding interoperability is made. My testing 
has shown that even desktop UAs tend to not bother to implement such 
syntax checking, instead recovering from syntax errors in proprietary 
ways. (For example, transform="translate(20, 0" causes a translation 
transform in all the UAs I have so far tested.)

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

Received on Wednesday, 28 December 2005 14:44:01 UTC