On 04/23/2013 12:39 PM, Thomas Beale wrote: > On 23/04/2013 10:37, Bert Verhees wrote: >> >> > have ADL, AOM, and object transforms >> >> What is missing is that xml offers validation and query out of the >> box, which means it has been developed and optimized for years by >> many companies and communities, and mostly is good quality software. >> > > ok but we just agreed that XSD doesn't do the kind of validation that > is needed by archetypes, so I think what you are really proposing is > XML based on Relax NG as a sufficiently powerful approach that would > a) implement the required constraint semantics of archetypes and b) > create data that can be queried by Xpath/Xquery out of the box? > > Is that your suggestion?
Exactly, that is my idea. I already did that for XML-schema, walking throug AOM-objects, and defining the structure-constraints and leaf-node constraints in XML-schema, but I don't like that very much because of the tricks I need to use. My hope is that Relax NG does not require these kind of tricks. But I am not completely ready studying it, but I found that some important restrictions (concerning the restrictions in structure) of XML Schema do not apply to Relax NG, and I also checked the leaf-node-simple-datatypes, where it seems to allow to define all possible ADL-constraints. So, I can build the structure of an archetype, keeping the paths in original names, keeping the constraints on the structure, and I can apply all leaf-node constraints. But at this moment I am very busy doing something else, and there is (quite) some time-pressure on that, working in the evening, that kind of thing. > > If so, my reaction would be: let's investigate as a community. I don't > think anyone has sufficiently investigated Relax NG or Schematron for > openEHR purposes, and in hindsight we probably should have. It would > be very interesting indeed to see how much better it would work than XSD. I will write a paper on it, how the structures and leaf-nodes are to be defined in Relax NG and publish that. Maybe there is still something left to ask or discuss, that is always good. It will take a few weeks before I have time for that. And what do I have then ADL -> Relax NG conversion -> automatic validation based on good quality of code XML-datasets -> XQuery -> full featured query language. Optional is AQL -> XQuery syntax transformation, some people find that important, I think it is possible. In fact, the complete OpenEHR ecosystem ready to work with XML, and almost everything running on matured code. That is the goal. Bert
