- From: Robert Diblasi <rdiblas@wpo.it.luc.edu>
- Date: Tue, 16 Oct 2001 15:40:57 -0500
- To: <www-svg@w3.org>
SVG Developers and W3 members ....others
[WARNING]: This is an open letter to W3 working group and SVG
Developers. I am questioning SVG in the spirt of finding out how
people feel. My comments may sound "rantish" but are given freely to
the group for discussion.....this note is not directed to any one
person in the SVG community!!!!.....but is directed at how SVG is
coded....and with hopes of adding a new feature to the up comming SVG
1.1 or 2.0 SVG updates...OK.....here we go.....please ask if you do
not understand what I am tring to say....I start with font-
information and go onto the path element
<tobias-wrote>
What bothers me is the cdata that is also being used in that it is
not readable by humans. Grant that FLASH isn't either, readable I
mean. But some of these great looking examples seem to be to much out
of a black box
</tobias-wrote>
The "font-face issue".....as I call it.....could it be solved if
you put the font in another file.......his is possible right?.......I
have seen this "font-junk-info" in the SVG code and I really do not
like it!....It is totally unreadable......and really goes aginst the
number 6 object / goal in XML 1.0 specification:
http://www.w3.org/TR/2000/REC-xml-20001006#sec-origin-goals
......heck ...I would argue that "path data' falls into the same
category as this font important........"not well described" ....this
is an importaint issue that I would like to discuss with SVG
Community.....please comment.....and please look at the XML
specification link I have provided.....and please look at this E-mail:
http://lists.xml.org/archives/xml-dev/200003/msg00199.html
and please make sure to read the follow ups.....
The point is that SVG could add some elements/attributes that a
writers of SVG code( could be used by people who like to use elements
and attributes to describe their code. This could also help machine
generated code :-) ....for example... One advantage is path data can
be broken into parts and each part could have "id" attribute added
to each of the parts....this would allow the changing exact parts of
the path data :-)......this would have several advantages....for both
declaritive and script/DOM access :-)
Part of the the E-mail responce states:
<snip>
In recognition that path data into a single attribute makes DOM access
difficult, SVG provides a series of convenience DOM methods to access
the contents of a <path> element on a per-command basis. You can
insert, delete and replace commands within a <path> element via the
convenience DOM methods.
</snip>
OK.....what about this....
First things first......what about access to X,Y coordinates?
Some of SVG finest have looked into the problem I posed and this is
what they had to say:
1)
(goto message 4711 on this yahoo SVG-developers group)
2)
yahoo message 5289 has come up with a solution by Manuel Bauwens
but this is not something the average coder should have to go
through...in my opinion!!!
What about declaritive ways of accessing the SVG path commands as
I mentioned above.....not everyone is going to include "scripting
language" in SVG file or even understand a scripting language or know
how to control the DOM....and in my opinion or should have to know
scripting.....I know I am being contradictory and redundant ....I
guess I would like to see declaritive elements and script/DOM have
the same funtionality when it comes to paths....This would allow SVG
the have strength to stand on its own......and at the same time...if
a person wishes to use script/DOM can....giving SVG the best of both
worlds .....right from the start!!...think of the advantage of having
paths commands described as elements when it comes to animation!! The
animation could use xlink to target just the part of path that needs
to be animated because it is labeled with "id" attribute....really
easy for people who do not what to learn "all the scripting
stuff"....and if they want to use scripting/DOM using "getElementById"
what could not be any easier :-)
[todays SVG path element and data attribute:]
<path id="path_5" d="M 100 100 L 300 100 L 200 300 z"
fill="red" stroke="blue" stroke-width="3" />
[some concept code (just an idea....not offical version ...this code
can be changed...and it would be great to see what people come up
with. .....remenber this would be just another way to create
paths....and would be very powerful when XML schema is created for SVG
think of the ability to restrain values in this code ...the XML
parser would take care a checking :-)]
<path fill="red" stroke="blue" stroke-width="3" >
<pathData>
<moveto>
<x>100</x>
<y>100</y>
</moveto>
<lineto>
<x id="change_this_x">300</x>
<y>300</y>
</lineto>
<lineto command="closePath">
<x>200</x>
<y>300</y>
</lineto>
</pathData>
</path>
This idea leads to every element can have a "id" attribute!....notice
that within the first "lineto" element...there is a "id"
attribute: "change_this_this_x".....very easy to access and
animate.....with script/DOM or declaritivly think about it!!
Chris, Tobias, Mike, Jon, Peter, others.....before SVG 1.1 or SVG 2.0
goes too far.....I think it would be nice to address these issues
again please :-)
By the way how do I submit a suggestion to SVG 1.1 /2.0 working
group....
a little rant from the mind of an XML idealist :-)......The semantic
web can work if we give it a chance!!......but for it to
work ....need to describe everything idealy........not try to shove
all information into one attribute because it makes file
smaller........really throwing SVG into question as a XML
format....path data really is just a flat file formate in an XML
attribute.
Question:
How come path attributes (commands) can not be described both
declaritivly and in the form path commands are in now? I do not see
the problem.....and can only come up with solutions.......
We all learn by sharing what we know
Robert A. DiBlasi
Received on Tuesday, 16 October 2001 16:41:06 UTC