Re: referencing properties from other specs in SVG 2

On May 18, 2012, at 4:24 AM, Tab Atkins Jr. wrote:

> On Thu, May 17, 2012 at 6:18 PM, Cameron McCormack <cam@mcc.id.au> wrote:
>> Since we will have some substantial parts of SVG split out into other specs,
>> like Filters, and various other CSS properties in other specs will be
>> required, I'm wondering how we should handle definitions and links to these
>> things.  Here are my current thoughts:
>> 
>> * We remove from SVG 2 definitions of any properties that are fully
>>  defined elsewhere.  For example, we don't need to re-define the
>>  'direction' property in SVG.  All we need to do is to mention that
>>  it applies to certain SVG elements.
>> 
>> * For the definition of what the set of presentation attributes is,
>>  and for the element summary boxes that mention them, we include
>>  properties in dependent specs that SVG 2 requires.  For example,
>>  the color-interpolation-filters property will be defined in the
>>  Filter Effects spec, and SVG 2 will have a normative dependency
>>  on Filter Effects, so color-interpolation-filters will be mentioned
>>  in element summary boxes and in the list of presentation attributes.
>>  If there comes to exist some specs that build upon SVG 2, which
>>  SVG 2 itself does not normatively depend on (and which therefore
>>  UAs can rightly implement or not), presentation attributes for
>>  these properties will not be mentioned in SVG 2.  SVG 2 will however
>>  have a spec hook that the other spec can reference to define
>>  a presentation attribute for itself, so that it will be allowed
>>  on stylable elements.
> 
> I agree with both of these.  Reference instead of redefining, but do
> include them in the lists of properties that apply in whatever
> context.
> 
> ~TJ
> 
I agree with the general proposal. Two things. 

1) We need to update the build system, so that it can automatically reference to CSS specs. This is an issue that we already have in Filter Effects and partly CSS Transforms.
2) We need a general comment about the syntax for presentation attributes. We should continue allowing 'unit less' values as well as scientific numbers. But we also need a comment that we use the general grammar and described units from the certain CSS spec where the property is defined (e.g CSS Values and Units, CSS Transforms). Then we could also remove a lot of parts from "4.2 Basic data types" [1]. I think that would be in common with the resolutions that we had during the Hamburg F2F.

Greetings,
Dirk

PS: Does this discussion need to got to public-svg? Why not www-svg?

[1] http://www.w3.org/TR/SVG/types.html

Received on Friday, 18 May 2012 10:58:19 UTC