[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RE: XML Design for Diverse Data
Hi Bryan, Here's a summary of Bryan's message: Consider this XML: <payment> <paymentpart>20</paymentpart> <paymentpart>45</paymentpart> </payment> A programmer may write code to sum each value in <payment>, e.g. sum = 0 loop through payment sum = sum + paymentpart With NVDL new elements may be introduced within <payment> and thus the programmer's code may fail. Bryan, is that a fair summary? Here are some thoughts: NVDL changes this content model: <payment> <paymentpart>20</paymentpart> <paymentpart>45</paymentpart> </payment> Into this content model: <payment> -- zero or more other-ns elements -- <paymentpart>20</paymentpart> -- zero or more other-ns elements -- <paymentpart>45</paymentpart> -- zero or more other-ns elements -- </payment> That is, it changes a closed content model into an open content model. Thus, if a programmer writes code assuming the first (closed) content model then his code is likely to fail. The problem is with the programmer's misunderstanding of the content model, not a problem with NVDL. What is exciting to me is that NVDL changes all schemas (XML Schema or Relax NG) from a closed content model to an open content model, without any changes to the schemas!. To state it a bit dramatically: NVDL unlocks closed schemas! Comments? /Roger
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] |
PURCHASE STYLUS STUDIO ONLINE TODAY!Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced! Download The World's Best XML IDE!Accelerate XML development with our award-winning XML IDE - Download a free trial today! Subscribe in XML format
|