- From: <bugzilla@wiggum.w3.org>
- Date: Thu, 02 Aug 2007 00:25:51 +0000
- To: www-xml-schema-comments@w3.org
- CC:
http://www.w3.org/Bugs/Public/show_bug.cgi?id=2825 cmsmcq@w3.org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|REOPENED |ASSIGNED Keywords|needsAgreement |needsDrafting ------- Comment #3 from cmsmcq@w3.org 2007-08-02 00:25 ------- At the WG's face to face meeting in June 2007 we discussed this issue (RQ-154 Versioning support, in particular forward processing of XSDL) and agreed to continue working on it. On the telcon of 13 July (http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2007Jul/att-0010/2007-07-13telcon.html) [member-only link], the WG reached substantive ('phase-1') agreement on a forward-processing proposal relying not on an xsd:fallback element but on minVersion and maxVersion attributes. The basic idea is that when schema documents are read, they are first pre-processed by being examined for attributes named xvc:minVersion and xvc:maxVersion (the names, especially the namespace, is subject to change). Each is treated as if declared with type xsd:decimal, and the value is compared to a decimal value representing the XSDL version of the schema processor, which I'll represent as "$version". If $version < @xvc:minVersion or $version > @xvc:maxVersion, then the attribute's parent element is suppressed. For example: <xsd:complexType xvc:minVersion="1.1"> <!--* definition suitable for 1.1 and later processors *--> ... </xsd:complexType> <xsd:complexType xvc:maxVersion="1.0"> <!--* definition suitable for 1.0 processors *--> ... </xsd:complexType> In this example, two versions of a complex type definition are supplied, one for 1.0 processors and one for 1.1 and later processors. It may be noted that 1.0 processors can be retrofitted with this mechanism, and that in some cases users of 1.0 processors which have not been retrofitted will be able to perform the preprocessing manually, or to arrange for the environment (e.g. a caching proxy) to perform it. The conformance rules governing schema documents are intended to apply to the schema document AFTER this preprocessing, not before it. A wording proposal is being prepared; I am changing the status keyword accordingly.
Received on Thursday, 2 August 2007 00:26:03 UTC