W3C home > Mailing lists > Public > www-svg@w3.org > April 2007

Re: SVG and proper XML design

From: David Woolley <forums@david-woolley.me.uk>
Date: Tue, 10 Apr 2007 07:50:32 +0100
Message-ID: <461B33B8.80401@david-woolley.me.uk>
To: www-svg@w3.org

Bill Dwyer wrote:

>  Simple: Create an XML grammar definition for paths and other
> arbitrary string formats such as style. It would be much easier to
> parse the language of it the grammar included something like:

The reason for the style syntax is that it is intended for direct human 
use (and as style sheets, rather than decorating individual elements).

More generally, I think one could actually make a good argument for not 
using XML for SVG.  Apart from the political need to use XML, the main 
reasons for using XML in SVG is to allow it to used in mixed namespace 
environments.  However, neither Adobe SVG viewer nor Firefox support 
this and a whole generation of authors has grown up viewing SVG as an 
external resource for HTML, rather than a truly embedded one for 
XHTML+XML, or one that can be decorated with additional namespaces.

The other reason for using XML or SGML syntaxes is that the document is 
intended to be directly viewable and editable by humans, and tha primary 
content is the text nodes; i.e. for true markup languages.  If one still 
wants a printable form, the syntaxes uses by PostScript and PDF are more 
machine friendly (PDF, although it looks to be binary is really a text 
format that has gone through a text compressor).

One of the main current drivers for SVG seems to be the mobile phone 
industry, for which data volume is still an issue, so they would benefit 
from a less redundant format, even if compression does compensate for 
the verbosity.

Note, one other use for which XML is beneficial is when using XSLT to 
generate SVG from an application specific markukp language.  I don't 
know if that is much done.
Received on Tuesday, 10 April 2007 06:50:49 UTC

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