Re: XML Schemas: Best Practices

[Jeff Rafter <jeffrafter@earthlink.net>]

> (1) There are many other schema languages besides XML Schemas:
>
>     - Schematron
>     - TREX
>     - RELAX

From my (very limited) experience with TREX it does not support this kind of
constraint (unless there is a TREX implementation of datatypes other XML
Schema Datatypes).  Which is not to say that it should not be considered for
future Best Practices-- it does offer several features that are not
available in W3C XML Schemas (such as interleave, ambiguous content models,
the not element and many more)-- and it is easy to learn.

> (3) The third option is to write a stylesheet to check the constraints.
> [Note: I got this idea from an article written by Rick Jelliffe.]

I think this is a great idea, but I don't see how it differs from option 1
fundamentally.  XSLT in this case is Yet Another Validation Language.  It
has to be learned as well.  Now, if you wanted to recommend a specific
validation language for this purpose (though I think that may be a bad idea)
then I think XSLT is a definite option-- of course Schematron is probably
better formalized for validation. Should options 1 and 3 be combined? or
more fully separated (for each possible schema language)?

Best Regards,
Jeff Rafter