- From: Eric Sirois <easirois@rogers.com>
- Date: Wed, 09 Jan 2008 14:57:53 -0500
- To: xmlschema-dev@w3.org
I don't how much I can add to the current discussion. I can provide some historical perspective on why the DITA schemas are the way they are and the cause of Eliot's headaches w.r.t to the DITA schemas In its current incarnation the DITA schemas only have redefine statements in the head schema documents that assembles other schema documents. We did this way so that we could validate the XML Schemas using Xerces-C. There was a bug opened against Xerces-J to address the issue. - https://issues.apache.org/jira/browse/XERCESJ-1219 I don't know if this will ever be fixed because it will probably break some schemas that are currently valid. If anyone attempts to redefine content model that have been redefined in the head schema and they attempt to use those with Xerces-C they will get schema validation errors. If a user wants to assemble a schema in a different manner add/remove schema document, they should create a different head schema. Doing it in this manner users can have different behavior based depending on the head schema that assembled the components. There are parent/child dependencies between files some the dependencies are flattened in the head schema. The current model, minus Eliot's issue for the moment, is the lowest common denominator that will allow the DITA documents to validate against the schemas against the most of the major or most commonly used XML parsers available so far. From a DITA perspective we should be able to define some markup (hopefully based on the proposal that Michael Kay to the WG) we get an output that will no longer makes use of the redefine mechanism but still make sense when dealing with head schema and its possible impact when storing these schema in a CMS or XML Database. Kind regards, Eric
Received on Wednesday, 9 January 2008 19:58:22 UTC