Re: [Zopexmlmethods-devel] Re: Zope3 XML sprint

[Philipp v. W. <ph...@we...>]

Hi Brent, hi all,

good news, Martijn checked in our xslt and xslt_examples products. Check 
them out at
   http://cvs.zope.org/zopeproducts/xslt
and
   http://cvs.zope.org/zopeproducts/xslt_examples
respectively

> I'm thrilled to hear that Zope 3 is including XML support.  I am a 
> little concerned by the references to XML Schema, though.  Is there 
> support for other schema languages, like DTDs, RelaxNG, etc?  Or just 
> the W3C XML Schema?  Many in the document markup world (as opposed to 
> data markup) have objections to XML Schemas.  I would hate to see Z3 
> tied solely to that technology for its XML support.

Don't worry. Zope3 wouldn't be Zope3 if tied you to a certain standard. 
That's actually the beauty of the Component Architecture. You can 
replace components with your own ones as long as they fulfill the interface.

Also, don't think that we already have full support for W3C Schemas. The 
_only_ thing our implementation does is read the schemaLocation 
attribute from the document element and try to find the interface object 
for that. Zope3 has currently no "idea" what a W3C schema is. It just 
deals with unique identifiers.

So, if you provide an XSLT style sheet that transforms to HTML, you need 
to provide a unique identifier for an "HTML schema". Obviously, there is 
no such thing, but Zope needs something there.

If you look at the configuration directives of our xslt_examples product 
(http://cvs.zope.org/zopeproducts/xslt_examples/configure.zcml?rev=HEAD), 
it needs to declare a schema for HTML just by giving some (fake) unique 
identifier. Whether that is actually a DTD, a W3C Schema, a RELAX NG or 
nothing doesn't matter in the moment.

 > Also, part of the
> beauty of XML is that in many instances you don't *need* a schema. 
> Well-formedness is enough.  Z3 should be able to accomodate those 
> use-cases as well.

Yes, it already does. If you don't want to provide a schema, then don't 
do it. If you still would like to be able to hook adapters and views to 
certain XML documents, then you need to provide a unique identifier. As 
already mentioned, this is just an identifier for the moment. Zope3 will 
probably support fetching schemas from their URI and parsing them, but 
this will totally optional and, of course, pluggable so that you can 
plug-in your own schema engine.

Philipp