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Hello kc, How do I get off the email list? Anthony ----- Original Message ----- From: "Karen Coyle" <[log in to unmask]> To: <[log in to unmask]> Sent: Friday, March 13, 2009 4:53 PM Subject: Re: [MODS] URL for the current version of mods > Andrew, it sounds like you are saying that there shouldn't be a generic > URL... ? I believe that people asked for it in the past, but maybe it's > not a good idea. It seems to work when updates are backward compatible but > not when they aren't. > > kc > > Houghton,Andrew wrote: >>> From: Metadata Object Description Schema List [mailto:[log in to unmask]] On >>> Behalf Of Rick Beaubien >>> Sent: Thursday, March 12, 2009 5:02 PM >>> To: [log in to unmask] >>> Subject: [MODS] URL for the current version of mods >>> >>> The current version of MODS is available both through a version >>> specific >>> URL (http://www.loc.gov/standards/mods/v3/mods-3-3.xsd) as well as a >>> more generic URL (http://www.loc.gov/standards/mods/mods.xsd). Can >>> users count on the more generic URL always pointing to the most recent >>> version of the MODS schema that is backwards compatible through version >>> 3.1? (I believe that there is a break in compatibility between version >>> 3.0 and 3.1). Or, to phrase the question a little differently, if a >>> new >>> version of the MODS schema was produced that was not backwards >>> compatible with versions 3.1-3.3, would it replace the 3.3 schema that >>> is now available via the generic URL >>> http://www.loc.gov/standards/mods/mods.xsd? I am asking this because >>> of >>> its implications for how the schemaLocation in mods instances should be >>> set up. >>> >> >> What goes in xsi:schemaLocation is the namespace URI and a URI to the XML >> schema for MODS. The namespace URI must match the targetNamespace >> attribute >> in the XML schema for MODS which currently is: >> >> targetNamespace="http://www.loc.gov/mods/v3" >> for the XML schema URI you should be using the version specific URI in >> the >> xsi:schemaLocation attribute of your XML instance document. Otherwise, >> as >> your question suggests when version 4 of the MODS specification comes out >> and it is not backward compatible, LC will have to change the target >> namespace URI to something like: >> >> targetNamespace="http://www.loc.gov/mods/v4" >> anybody still using version 3 of MODS and who mistakenly used the generic >> URI in their xsi:schemaLocation attribute of their XML instance documents >> will now have a problem since the targetNamespace in the XML schema >> returned from the generic URI will not match the namespace URI they used >> in the xsi:schemaLocation attribute specified in their XML instance >> documents. If >> the XML instance document is being read by an XML parser that is schema >> aware, then the XML parser will throw an error, otherwise the application >> processing the MODS instance document will not know there is a problem. >> The generic XML schema URI should never be used in xsi:schemaLocation. >> >> Unfortunately, the LC web site doesn't make it clear which one you should >> be >> using and when you dereference the generic URI you get back an HTTP 200 >> OK >> status with the HTTP entity containing the latest version of the MODS >> schema. >> What I believe the LC web site should be doing when dereferencing the >> generic URI is to respond back with an HTTP 302 Found status and an HTTP >> Location >> header containing the URI to the latest version of the MODS schema. Then >> it >> would be obvious that you should be using the version specific URI >> instead >> of the generic URI. >> >> >> Andy. >> >> >> > > -- > ----------------------------------- > Karen Coyle / Digital Library Consultant > [log in to unmask] http://www.kcoyle.net > ph.: 510-540-7596 skype: kcoylenet > fx.: 510-848-3913 > mo.: 510-435-8234 > ------------------------------------