Re: 'Re: [xml] "Next XML schema implementation steps (poll)"'

[Daniel Veillard <veillard redhat com>]

On Thu, Aug 19, 2004 at 11:04:24AM +0200, Kasimier Buchcik wrote:
> Hi,
>
> on 8/18/2004 6:50 PM Bryan Berkowitz wrote:
>  > Kasimier Buchcik wrote:
>  >>Yes, <key>, <keyref> and <unique> are not supported yet.
>
> > Could we add these features to the list of things to do? I would find 
> > them very useful, in fact I might be able to help out with the 
> > implementation.
>
> That would be great! :-)
> For parsing those elements I recommend looking at 
> "xmlSchemaParseSimpleType" in xmlschemas.c; there you'll find an example 
>   of how to use the new error functions, and of validation of attributes 
> and their values.
>
> The main issues I see here:
> 1. how to restrict the XPath expressions as imposed by the spec
> 2. just keep in mind that the XPath execution should be able to work on 
> a stream someday (as mentioned by Daniel)

  I noticed that I missed that point. The code for this is the pattern
engine (include/libxml/pattern.h & pattern.c), but it's too limited right
now (namespaces are not implemented for example), and a push/pop API would
be needed for real streaming.

  Among the features missing of the schemas implementation, there is the
need of a streaming interface, right now we validate only trees, I believe
the current implementation should be able to work after some refactoring
based on a SAX2 stream, but it's not a piece of cake.

Daniel

-- 
Daniel Veillard      | Red Hat Desktop team http://redhat.com/
veillard redhat com  | libxml GNOME XML XSLT toolkit  http://xmlsoft.org/
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