yes i know, a big task ;)
i already got a solution dynamically generating xml structures with the help of
XSOM parser. addressing elements (with wildcards) is done inside custom XML access class with xpath.
it can handle optional and choice elements too which are cleaned when finished with working with the document if not set. the stuff works fine for our requirements, but more requirements are coming up and i am getting to the point where i am building a "kind of" xml database. of course this cannot be my core-competence (i want to build business software and no xml database), so i am looking for existing tools.
using binding frameworks like jaxb or xmlbeans is not an option, because it is not flexible on changing versions of XSDs. further more when working with XSDs dynamically it shows up very unhandy.
apart from my need to have an in-memory xml database (-> i do not need persistent data on my harddisk) i really wonder why xml databases still are far away from getting ahead with its relational-brothers. in my point of view, the only reason can be the market dominance of relational databases and legacy apps.
i think working with xml is getting very frequent and with the interoperable XML standard there definitely is a killer application for a wide use of xml-databases.