Re: SVG in text/html

Sam Ruby wrote:

> 1) People often author content which is inserted into a larger context. 
>  Blogs, wikis, comments, are but a few examples.  Requiring the entire 
> page to be xml well formed, and requiring that none of the page be 
> displayed if there is any well formedness errors, is a non-starter for 

What you are basically saying is that the whole XML concept is flawed. 
As I understand it, the reason for requiring well-formedness is not, as 
some people seem to think, so that you can detect and throw out 
documents with very poor syntax, but so that you can mix languages and 
safely embed content, i.e. it is to support the X in XML.  A 
well-formedness violation basically means that you no longer know which 
language (namespace) you are in, and that's why parsers are expected to 

I think the HTML5 approach would end up being to add yet more error 
recovery rules, to cover SVG in HTML cases, MathML, in SVG in HTML 
cases, etc.

> most sites.  I'd love to see the day when svg could be copy/pasted into 
> MySpace and MathML copy/pasted into Facebook, and have it "just work".

That was the key design aim of XML!

Incidentally, as noted in one of my replies to a recent thread on 
www-html, it is not a good idea for blog engines, etc., to simply copy 
third party content into the matrix.  They should be restricting it to 
content that is "well formed" in all intended languages, as part of 
making safe.  If it isn't well formed, some browsers may not correctly 
detect the end of the embedded content, or may be tricked into 
recognising early, thus frustrating the sort of "untrusted" marking that 
was being proposed in that thread, and requiring that any trust marking 
be orthogonal to the DOM structure.
> 2) There are is well-known and widely deployed browser which will not 
> display content served as application/xhtml+xml at all.

Those browsers support embedded VML, not embedded SVG (and actually do 
so using full XML namespace syntax, even though that is not supposed to 
be used in documents served as text/html!

Note, in general, I think cross-posting between mailing lists is a bad 
idea, as replies are likely to get rejected or moderated on most of 
them, but I've made an exception in this case and even added www-html, 
which seems to me to a more appropriate to discuss whether the XML 
concept was a mistake.  Please note that I am only subscribed to www-svg 
and www-html, amongst the lists used.

David Woolley
Emails are not formal business letters, whatever businesses may want.
RFC1855 says there should be an address here, but, in a world of spam,
that is no longer good advice, as archive address hiding may not work.

Received on Sunday, 14 October 2007 09:22:14 UTC