[lxml-dev] etree.Element from RNG schema?

[Stefan Behnel]

Hi,

Frank Cusack wrote:
> Can lxml give me back an Element object from a parsed RNG schema?
> That is, given
> 
>   parser = etree.RelaxNG(etree.parse(file("foo.rng")))
> 
> I'd like to do something like parser.getroot() in order to get back
> an Element/ElementTree which is like the original schema except with
> grammar/define's expanded.
> 
> What I want is to go from
> 
>   <grammar>
>     <start>
>       <element name="foo">
>         <ref name="bar" />
>       </element>
>     </start>
> 
>     <define name="bar">
>       <text />
>     </define>
>   </grammar>
> 
> to
> 
>   <element name="foo">
>     <text />
>   </element>

libxml2 does not expose the internals of its schemas (RNG/XSD).

But if all you want is resolved <ref> tags, you can do that yourself very
easily, without passing through RelaxNG at all. (You might want to use
.iter(tag) for that instead of XPath, BTW).

Stefan