- From: C. M. Sperberg-McQueen <cmsmcq@blackmesatech.com>
- Date: Tue, 24 Aug 2010 07:30:29 -0600
- To: "McBride, David" <dmcbride@quicinc.com>
- Cc: "C. M. Sperberg-McQueen" <cmsmcq@blackmesatech.com>, "xmlschema-dev@w3.org" <xmlschema-dev@w3.org>
On 23 Aug 2010, at 10:39 , McBride, David wrote: > I’m having difficulties defining a logical relationship within a > complex type. The complex type contains 4 sub-elements. Let’s call > them A, B, C, D. The logical relationship is this: > > 1. One, or more of elements B, C, or D are required. > 2. There may be zero or more instances of element A. > 3. Element A may never be the only element. In other words, > there may only be an instance of A, if there is also at least one > instance of B, C, or D. > > If I was just dealing with B, C, and D, I could handle that. > However, adding the requirements for A has thrown me. If one of B, C, and D is required, then your constraint 3 seems always to be satisfied. Element A will never be the only element, since there will always be a B, C, or D. Or have I misunderstood the constraints? If you do not care about the order, then the simplest thing might be the XSD equivalent of the regular expression (A*, (B | C | D)+) If I've misunderstood the constraints, then this content model may not do the job -- explaining why not would be a good step towards clarifying the requirements. HTH -- **************************************************************** * C. M. Sperberg-McQueen, Black Mesa Technologies LLC * http://www.blackmesatech.com * http://cmsmcq.com/mib * http://balisage.net ****************************************************************
Received on Tuesday, 24 August 2010 13:28:43 UTC