Let me give an example:
RELAX NG has a feature unsupported in other schema languages called
interleave. If I say this:
citation = first & subsequent
… I am saying that a citation must include both first and subsequent
patterns, but order is unimportant. This is a great feature for a lot
of reasons, not least it makes it easier on developers writing these
files.
OK, cool. The thing is, I cannot use interleave if those patterns are
defined by attributes.
Practically speaking, what this means is that if I change the content
model as you are advocating, then I do one of two things:
-
I do not enforce any constraints on how often these elements
appear. So one could have five different cs:layout elements with the
same cs:position attribute, and it would still be valid. So it would
be valid, but effectively wrong.
-
Constrain the occurrence to either one “all” or both a “first” and
"subsequent" (as now), except that in the second case order would be
enforced (which it is probably not now). A developer in that case MUST
have the correct order to be valid.
Thoughts?
Bruce
Well… if there is any trade of, I think you better stick with what
you had. I just noticed the difference for the level of and
found it somewhat odd. But I leave it to you as to say what is best.
I think that being able to convert it to XML schema might be very
useful. More useful that having “symmetry”.
Johan
It’s tricky. You’re right that it is “somewhat odd.” OTOH, it’s also
worth noting that XML Schema has no support for interleave. It’s not
possible to have an XML Schema where order is unimportant, which is
among the reasons I haven’t yet created one.
To me the most important thing is that the schema be as good as it can
be, with “good” measured by:
- feature completeness
- elegance of design (which includes consistency)
- ease of implementation for GUI and tools developers
Not sure what the best balance is.
I personally dislike XML Schema intensely. It’s way too complex where
I really don’t care, and way too simple where I do.
Bruce
CSL Editor has made some nice progress. It’s not yet done, and there
are still a few bugs that I need to iron out. Anyway, before
completing it, I of course need the final, or at least a very close
to final schema. I’ll finish the development and release CSL Editor
once that schema is ready.
CSL Editor wil require 10.4. It is possible to write this app for
10.3, but in the way it is currently written that would be a complete
rewrite. I am going to stick with 10.4. 
Cheers,
Johan
The second seems better to me. Won’t almost all records be generated
by code, rather than by hand? In that case enforcing order should be
a one-time code it right problem … or do I misunderstand?
–J