Re: Reference CSS Values and Units instead of specifying <length> in SVG (was: Re: Minutes, 15 jan 2015 SVG call)

Sorry if this has been mentioned before, it occurred to me a long time ago.

Could it be possible to have one length (or other) value tied to
another in the following fashion?

<rect id="rect_1" width="6" height="6"/>
<rect id="rect_2" width="url(#rect_1):width" height="12"/>

There are many ways this could be encoded, the objective, to tie the
value of one attribute to the value of another using a declarative
method in a fashion similar to <use>, but at the attribute level.

On 1/16/15, Dirk Schulze <> wrote:
> Hi,
> A question to the units discussion:
>> On Jan 15, 2015, at 10:33 PM, Chris Lilley <> wrote:
>> <length> referenced to CSS is incorrect for SVG
>>   Tav: length goes to css definition which is not ours, svg
>>   differs on percent, unit identifiers etc
>>   svg 1.1 already did that right
>>   Tav: we need a two step definition for attrs and properties
>>   ChrisL: this is different for svg attrs compared to properties.
>>   it was right in svg 1.1
>>   Rossen_: so it was right in 1.1
>>   ChrisL: assume we want to refer to css3 values and units
>>   heycam: i made some edits and split percentages from length for
>>   comnsistency with css
>>   ... the other part for unitless lenghts, not sure but may be a
>>   mistake
>>   ... to link directly, we have something in types that supports
>>   unitless lengths
>>   ... but css3 supports parsing of lengths without units in some
>>   contexts so we should define it that way
>>   ... invoke parser with that flag set
>>   ChrisL: sounds like you know what spewc changes are needed
>>   Tav: odd to click on length on rect and get that. its a
>>   property. don't see that you dont need units
>>   heycam: keep in types chapter, and then link to css spec there
>>   whle talking about the unitless flag
>>   <scribe> ACTION: heycam to fix length to point to types chapter
>>   and flag unitless lengths [recorded in
> I do not understand why it would be wrong to separate <length> from
> <percentage> and let both reference CSS Units and Values as it does in SVG 2
> right now? Many of the attributes are presentation attributes now and we
> have to follow CSS grammar here. Don't forget that CSS defines more units
> than SVG has today and probably will define more in the future. It would be
> incompatible to CSS and wrong to do it as SVG 1.1 did and specify <length>
> any different.
> There was one mentioning of unit less values for attributes. There is no
> need to specify anything in SVG 2 for that. CSS Syntax allows presentation
> attributes to omit units. There is no backward compatibility breakage here.
> Do not change values and units back to the SVG 1.1 state but reference CSS
> where appropriate.
> Greetings,
> Dirk

Education is what you get when you read the fine print
Experience is what you get when you don't.

Received on Monday, 19 January 2015 02:33:51 UTC