Hi Uche, > I'd guess that he's hinting that the closed grammar schema approach will > always be susceptible to such problems, and I think he's right. (Cue > the Schematron advocacy here). I wanted to touch off a discussion of > how RELAX NG or DSDL overall can meet typical schema needs without > falling into such traps or requiring severe back-bends by schema > authors. At a minimum, could RELAX NG grow a pragma to always allow > xml:* attributes?
I have dedicated a chapter of my book to this type of issues (http://books.xmlschemata.org/relaxng/relax-CHP-12.html)... With RNG as it stands right now, my advise to schema authors is to define each of their element content as a named pattern so that people can add their stuff by combination. If you wanted to make it easy to add stuff to every element in a single oparation (without having to combine each of the element content one by one), you could add to each element definition a reference to a pattern that you could name "extension" and define this pattern as "empty". By combining this pattern with additional stuff (like the xml:* attributes in your example), people could add their additions to every element in a single step. Now, your question is: does it deserve a new pragma? Technically speaking, that would be easy to add to grammars a an new pattern (right now grammars have only a start and define patterns) that could be called "common" or whatever and which would hold patterns to interleave into each element. This pattern would be added to each element content during the simplification process and that would not even change the core semantics of RNG. And this pattern could be local to its grammar so that authors can restrict its scope. The big questions are "is that worth adding a new complexity to the language?" and if yes "does that justify a RNG 1.1?"... My 0.02 . Eric ------------------------ Yahoo! Groups Sponsor --------------------~--> Get Bzzzy! (real tools to help you find a job). Welcome to the Sweet Life. http://us.click.yahoo.com/A77XvD/vlQLAA/TtwFAA/2U_rlB/TM --------------------------------------------------------------------~-> Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/rng-users/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
