2068 2005-09-09 02:58:45 +0000 R-078: Issue to do with definition of substitution groups, block, and UPA 2009-04-21 19:24:57 +0000 1 1 1 Unclassified XML Schema Structures: XSD Part 1 1.0 only All All CLOSED FIXED P2 normal --- 1 sandygao ht www-xml-schema-comments oldest_to_newest 5948 0 sandygao 2005-09-09 02:58:45 +0000 Consider the following example: <element name="e1" block="substitution"/> <element name="e2" substitutionGroup="s:e1"/> <complexType name="t"> <choice> <element ref="s:e1"/> <element ref="s:e2"/> </choice> </complexType> The choice violates the constraints for UPA, because "e2" is in "e1"'s substitution group. However, "e2" can never substitute "e1". Should the definition of substitution group (Schema Component Constraint: Substitution Group) be modified? See bullet 1 from: http://lists.w3.org/Archives/Public/www-xml-schema-comments/2001OctDec/0049.html 5949 1 sandygao 2005-09-09 02:59:11 +0000 See the discussion from the 01/03/2002 telecon: http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Jan/0006.html Further discussion at the 01/24/2002 telecon: http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Jan/0082.html Resolution: The WG resolved to classify R-78 as an error, and instruct the editor to draft an erratum, defining substitution group not recursively as now but using a formulation similar to that of 3.3.6 Substitution Group OK (Transitive), while not changing other constraints (such as the requirement that the data types of the two elements stand in a particular derivation relation). See: http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Jan/0101.html Proposed text: http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Oct/0175.html reviewed at Oct. 11 telecon. Approved with suggested ammendments (see meeting minutes for details). Erratum E1-23 added