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[Bug 3836] Easier complex type restriction

From: <bugzilla@wiggum.w3.org>
Date: Fri, 13 Oct 2006 20:32:51 +0000
To: www-xml-schema-comments@w3.org
Message-Id: <E1GYTi7-0001mj-8u@wiggum.w3.org>


           Summary: Easier complex type restriction
           Product: XML Schema
           Version: 1.1 only
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Structures: XSD Part 1
        AssignedTo: cmsmcq@w3.org
        ReportedBy: sandygao@ca.ibm.com
         QAContact: www-xml-schema-comments@w3.org

[The problem]

It's desirable to provide schema document syntax that eases complex type
restriction. Currently the derived type has to repeat almost the entire base
content model, which may be very inconvenient in some cases.

1. It's common that, especially when people are paying more and more attention
to schema evolution, a wildcard in the base type needs to be replaced by some
element declarations. This seemingly simple task also requires an entire copy
of the unchanges portions of the base content model.

2. When the base content model has elements with anonymous types or identity
constraints, it's not possible to repeat them, hence making it impossible to
refine the base type, at least without extensive use of named groups.

3. When a complex type restricts a base type from different namespace, again
it's impossible to repeat the base content model, because many of the elements
have a {target namespace} that's different from the current schema document's
target namespace.


1. Make it possible to replace pieces of the base content model without
repeating the rest. May need to use a path language like SCD to specify which
pieces to replace.

2. Allow a targetNamespace attribute on local element/attribute declarations to
be able to declare declaration in other namespaces.
Received on Friday, 13 October 2006 20:32:58 UTC

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