- From: C. M. Sperberg-McQueen <cmsmcq@acm.org>
- Date: 07 Dec 2005 18:56:29 -0700
- To: Tobin M Clough <tclough@us.ibm.com>
- Cc: W3C XML Schema Comments list <www-xml-schema-comments@w3.org>, xmlschemaTSfaq@nist.gov
On Mon, 2005-12-05 at 15:33, Tobin M Clough wrote: > Hello, > I think this is a very simple question, but I can't seem to find any > documentation on it. Is this a legal application of the xsi:type > construct?: > <isOkay xsi:type="xsd:boolean"/> > With validation turned off, it seems like this would be a reasonable > representation of no value (null) for a data item that is either > true, false, or empty. If there is no schema, or if 'isOkay' is declared with type xsd:anyType, xsd:anySimpleType (or, in XML Schema 1.1, xsd:anyAtomicType), then it's certainly legal to supply an xsi:type attribute with the value xsd:boolean (assuming that xsd is properly bound as a namespace prefix in this context). On the other hand, since the empty string is not a member of the lexical space of xsd:boolean, the 'isOkay' element shown above will not be valid. If the element 'isOkay' is declared nillable, then <isOkay xsi:type="xsd:boolean" xsi:nil="true"/> would be valid. But I believe you are talking about using xsi:type with undeclared elements; for those, empty elements will be valid only when the empty string is a member of the relevant lexical space. Hmm. I notice that you talk about using this "with validation turned off". Under those circumstances, of course, it hardly matters whether the element would be valid or not if it *were* validated. I hope this helps. -C. M. Sperberg-McQueen World Wide Web Consortium
Received on Thursday, 8 December 2005 01:59:11 UTC