[xsd-users] W3C SMIL Schema

[Mark Watson]

Hi,

I have been trying to get xsd to compile the W3C SMIL schema at
http://www.w3.org/TR/2005/REC-SMIL2-20050107/smil-SCHEMA.html. I am new to
both xsd and SMIL.

Aside from a few minor bugs, these Schemas seem to have the property that
there are mutual cross-references between namespaces. Specifically, when
compiling the root file (smil.xsd), there are first a number of included
files which define symbols in the smil20 namespace. Some of these use
symbols from the smil20lang namespace, in which nothing has yet been
defined. There are no import statements for smil20lang in these included
files, which cause xsd to generate errors and it¹s not possible to add an
import for smil20lang, because the definition of most things in this
namespace relies on the smil20 stuff we are trying to define.

Re-arranging the files so that all the initial smil20 stuff is done first,
and following this with the import of the file which defines things in
smil20lang works better, but I still get reports from xsd of unrecognised
symbols in one included file which were clearly defined in an earlier
included file.

Furthermore, I believe there are further additions to smil20 which happen
later but are referenced for the earlier smil20lang stuff.

I am not an expert in XML, and one question I have is whether this kind of
referencing ­ which seems not to respect any kind of compilation order ­ is
valid in XML but just not supported by xsd, or whether it is not allowed in
XML at all.

Any help greatly appreciated.

Best regards,

Mark Watson