Re: NVDL, SVG validation

Hi Jirka,

On Jan 3, 2008, at 18:18 , Jirka Kosek wrote:
>
> NVDL itself doesn't have provision for this. But you are not first  
> with
> such requirement. Our implementation JNVDL has extension for this,  
> see:
>
> http://jnvdl.sourceforge.net/extensions.html#extensions-usewhen
>
> I think that something very similar will get into next official  
> version
> of NVDL language. There have been discussion about similar NVDL  
> feature
> in the past and I have intended to restart this discussion on JTC1/ 
> SC34
> (body which maintains NVDL) adter other NVDL errata are processed.

That's great news, thanks for pointing the work done in jnvdl. It  
looks indeed like this would solve a lot of issues with languages/ 
profiles sharing the same namespace. I suspect the regexp-based  
extensions would be harder to have adopted, SVG and XHTML are "public"  
enough use cases for useWhen*.

> I think that the biggest mistake of XHTML is its definition of  
> "strictly
> conformant document" which prevents extensibility. It's perfectly OK  
> to
> put custom elements/attributes from other namespaces almost everywhere
> in almost any XML document. For example our Relaxed
> (http://relaxed.vse.cz) validator (RELAX NG + Schematron based) allows
> it -- basic schema for HTML/XHTML simply ignores everything which is  
> not
> in XHTML namespace. But you can also use more strict version of schema
> which rejects everything what is not in XHTML namespace.

There's a lot of history behind such choices. I've seen indeed many  
debates about "ignore what you don't understand" (an old rule for html  
parsing) and the terms of XHTML conformance. Anyway, specs and  
implemented support for compound XML documents should keep evolving  
together in the right direction.

-- 
olivier

Received on Monday, 7 January 2008 02:37:03 UTC