$Date: 2010/04/07 11:45:56 $
Abstract
This document contains disposition of comments for Associating Schemas with XML documents 1.0 (First Edition)
The current xml-model draft requires fetching of resource in
order to determine schema language used for an associated schema if
schema type can't be determined just from media type as specified in the
type pseudo-attribute.
Origin: Several people raised this objection, for example http://lists.w3.org/Archives/Public/public-xml-core-wg/2010Jan/0049.html and http://lists.w3.org/Archives/Public/public-xml-core-wg/2010Feb/0008.html.
Add new pseudo-attribute called schematypens which can be used for specifying
namespace of the schema language used. Combination of schematypens and type is able to cover all currently widely
used schema languages as shown in Table 1, “Determining schema language”.
Table 1. Determining schema language
| Schema language | type | schematypens |
|---|---|---|
| DTD | application/xml-dtd | not specified |
| W3C XML Schema | not specified or application/xml | http://www.w3.org/2001/XMLSchema |
| RELAX NG | not specified or application/xml | http://relaxng.org/ns/structure/1.0 |
| RELAX NG – compact syntax | application/relax-ng-compact-syntax | not specified |
| Schematron | not specified or application/xml | http://purl.oclc.org/dsdl/schematron |
| NVDL | not specified or application/xml | http://purl.oclc.org/dsdl/nvdl/ns/structure/1.0 |
Example 1. Multiple schemas associated
<?xml version="1.0"?> <?xml-model href="http://www.docbook.org/xml/5.0/rng/docbook.rng" schematypens="http://relaxng.org/ns/structure/1.0"?> <?xml-model href="http://www.docbook.org/xml/5.0/rng/docbook.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?> <book xmlns="http://docbook.org/ns/docbook"> … </book>
The current xml-model draft prohibits other pseudo-attributes
then those which are directly defined in the draft. However in the future it
might be necessary to introduce new schema specific pseudo-attributes
similar to Schematron's phase.
Origin: Several people raised this objection, for example http://lists.w3.org/Archives/Public/xml-editor/2010JanMar/0000.html and http://lists.w3.org/Archives/Public/public-xml-core-wg/2010Feb/0008.html.
Allow additional pseudo-attributes by removing the following text from the draft:
Documents must not specify other pseudo-attributes on xml-model processing instructions.
and by adding:
An xml-model processor must process all xml-model processing instructions properly and must pass on to the application the full parsing result for each xml-model processing instruction.
The draft provides both an href pseudo-attribute, and also an
explicit type pseudo-attribute. As discussed
in the applicable RFCs and the TAG's finding on Authoritative
Metadata, any Content-type returned with status code 200 from an HTTP
GET is authoritative, regardless of what might be specified in a Type
pseudo-attribute.
Origin: Noah Mendelsohn http://lists.w3.org/Archives/Public/xml-editor/2010JanMar/0001.html.
xml-model specification should deal explicitly with the case where the
authoritative metadata contradicts the explicitly specified type.
Specification should say that type pseudo-attribute is
ignored when it is different from the authoritative type received in
HTTP response.
The draft is not stating when to prefer xml-model over other possible schema association techniques.
Origin: WG
Add the following paragraph as the last paragraph of Introduction.
It should be noted that this specification is not meant as a replacement for other technologies that provide more general and indirect schema association features like NVDL and XProc. This specification is complementary technology which can be used when it is necessary to store ad-hoc schema associations directly inside XML document.
The specification should say very explicitly that the presence of xml-model PI is not in itself an instruction to any processor to validate the document, and not a statement that the document is not to be processed without validation. It is a declarative statement of the relation between the document and some (external) schema.
Origin: C. M. Sperberg-McQueen http://lists.w3.org/Archives/Public/public-xml-core-wg/2010Feb/0008.html.
Append the following text at the end of the second paragraph of Introduction.
Presence of xml-model processing instruction is not in itself an instruction to any processor to validate the document, and not a statement that the document is not to be processed without validation. It is a declarative statement of the relation between the document and one or more external schemas.