Re: [xml] validation fails for embedded RELAX NG schema

[Michael Ludwig <mlu as-guides com>]

Jerzy Jalocha N schrieb:

> I would like to use a RELAX NG schema that is embedded inside some
> "outer" XML file:
>
> <?xml version='1.0' encoding='UTF-8'?>
> <wrapper xmlns='http://namespace.net/something'>
>    <!-- Here would go a lot of stuff that belongs to the wrapper. -->
>    <grammar xmlns='http://relaxng.org/ns/structure/1.0'>
>       <start>

[...]

> Sadly, xmllint (2.6.32) complains about an empty schema:
>
> example-schema.xml:0: Relax-NG parser error : xmlRelaxNGParse:
> example-schema.xml is empty
> Relax-NG schema example-schema.xml failed to compile.

I'd be surprised to discover that embedding RNG schemas in arbitrary
documents is actually supported. What makes you think it is?

> I know, that I could pre-process my "mixed" document, and extract the
> schema with XSLT prior to validation. But this would make the whole
> project quite a lot more complex, thus I'd like to avoid it, if
> possible.

Extracting a subtree from a document doesn't seem too difficult, and
could probably be done using nothing but DOM.

> I guess, that I am not doing anything illegal by using two
> vocabularies side-by-side, as long as I use separate namespaces,
> or am I wrong?

No, you're right. That's what namespaces are for.

> Is this a known limitation of xmllint, or maybe a bug?

Again, what makes you think xmllint (or any other parser, for that
matter) should auto-detect embedded RNG schemas in arbitrary
documents?

Michael Ludwig