Re: Animating SVG attributes from Web Animations

Apologies for responding to the wrong mail list but that is where the
question arose.

You say:

"(But there's nothing wrong with putting strings like that in CSS; I'm
unsure why you think there's a meaningful difference between <path
d="giant string"> and <path style="d: 'giant string'">.)"

I didn't say there was a meaningful difference. I just asked whether CSS
implementations were capable of handling 1 Megabyte or even 50 kbyte
strings. Current SVG implementations have a problem handling very large
numbers  of animated path descriptions while handling long path
descriptions pretty well. (In consequence I have to distort the structure
of an animation by compounding paths together to get reasonable
performance.)
The question was whether CSS implementations would be better or worse than
the SVG implementation ?

The intrinsic difference is best shown by:
(1)
path.abc {d:giantstring}  in a stylesheet xyz.css and

<path class="abc"/> in the file ashape.svg

in the SVG document compared with:

(2)
<path d="giant string" /> in the file aus.svg

As it currently exists in SVG 1.1, in (2) the d attribute is tightly bound
to the svg document before rendering.

In (1), depending on the stylesheet applied to the document, it defines
either the outline of Australia or New Zealand dependent on the style
sheet  which may even be supplied by the user overriding the intention of
the author.

You also say:

"A <path> carries no intrinsic meaning, just like an <img>; it is
completely opaque to a search engine, screen-reader, or other machines.  It
is entirely unlike text content."

The example above in HTML would be:

(1)
h2.abc {text:giantstring}  in a stylesheet xyz.css and

<h2 class="abc" text=""/> in the file sometext.htm

in the HTML document compared with:

(2)
<h2 text="giant text string" /> in the file meaningfultext.htm

There is a difference in how the XML elements are written in SVG and HTML.
HTML writes the content of the element as  the content of the h2 whereas
SVG writes the content of the path element as a d attribute. HTML quite
rightly does not allow  the text content of the h2 to be changed by styling
otherwise  the search engines would produce rubbish.  Similarly, SVG 1.1
does not allow the graphical content of the path element to be restyled by
a stylesheet. Otherwise a person reading the path description on a high
quality search engine or screen reader could not understand the meaning at
a superficial level.

Even the simplest of search engines should be able to see that:
<path d="M0,0h30v-30h-60v30h30v30h30v30h-60v-30h30"/> defines a flow
diagram with two boxes just as a search engine should be able to recognise
<h2>Schemat przeplywu</h2>

Students at Oxford Brookes University since 2000 have regularly had exam
papers with path descriptions much more complicated than the one above that
they must understand and most get good grades with no real difficulty. Only
three have  had any idea what the HTML meant.They were European Union
Erasmus exchange students from Poland.

Personally I have no problem with theSVG and have no ability to say what
the HTML means.  I tried Google for the HTML and the first 50 responses
were in a language that I did not understand. I tried M0,0h30 and at least
there was one entry in the top 10 that was concerned with SVG.

Zaineb BEN FREDJ's  thesis "Enquiring and Reasoning Over Diagrams Using the
Semantic Web" describes a system GraSSML built on SVG that can be used by
blind users to reason over a range of formal diagrams. There is also
interest in geometric search engines, see
http://visionair.ge.imati.cnr.it/gse/.

The main point is that the text in HTML is content as is the d attribute of
SVG and neither should be changed by a stylesheet and a decent search
engine should be able to extract meaning from both, which is the reason
that a stylesheet should not be allowed to change rthe content in either.