- From: <noah_mendelsohn@us.ibm.com>
- Date: Mon, 23 Aug 2004 09:31:36 -0400
- To: Jochen Wiedmann <jochen.wiedmann@freenet.de>
- Cc: xmlschema-dev@w3.org
I'm not 100% sure I understand your question, but consider the following: schemadoc1.xsd: <xsd:schema targetNamespace="ns1Uri"> <xsd:include schemaLocation="schemadoc2.xsd"/> </xsd:schema> schemadoc2.xsd: <!-- no targetNamespace on this one --> <xsd:schema xmlns:ns1="ns1Uri"> <xsd:include schemaLocation="schemadoc2.xsd"/> <!-- this winds up defining {ns1Uri, someelement} --> <!-- the type referenced is still xsd:integer --> <xsd:element name="someelement" type="xsd:integer"> <xsd:annotation> <xsd:documentation xmlns:html="http://www.w3.org/1999/xhtml"> <!-- the following still uses {http://www.w3.org/1999/xhtml,p} --> <html:p>here is a paragraph</html:p> <xsd:documentation> </xsd:annotation> </xsd:element> </xsd:schema> The pertinent clause of the schema recommendation states [1] regarding include of a schema document with no targetNamespace: "anywhere the ·absent· target namespace name would have appeared, the ·actual value· of the targetNamespace [attribute] of SII' is used. In particular, it replaces ·absent· in the following places: * The {target namespace} of named schema components, both at the top level and (in the case of nested type definitions and nested attribute and element declarations whose code was qualified) nested within definitions; * The {namespace constraint} of a wildcard, whether negated or not;" I think that's pretty clear. In the case of documentation, for example, you are using namespaces but NOT the targetnamespace. Same is true in type type= reference. In general it is NOT references or uses of elements from other namespaces that get affected, it's the names of things that are defined (and wildcards.) If you are building a schema processor, it is absolutely essential that you read the recommendation and understand it in detail. It is not, unfortuantely, a specification that is easy to grasp the first few minutes you read it. You will find, though, that it takes great care to spell out the details of the language with some care, and that's exactly what you need as an implementor of a processor. In general, you want to learn what the schema components (type definitions, etc.) are and what the constraints on them are. Layered on that, you can find out how the components are built up from the information provided in schema documents; for example, you'll find out that some of the properties of a type definition may be inherited from the base type, and that base type may be declared in a different schema document. I hope this answers your question about include. Good luck! [1] http://www.w3.org/TR/2004/PER-xmlschema-1-20040318/#compound-schema -------------------------------------- Noah Mendelsohn IBM Corporation One Rogers Street Cambridge, MA 02142 1-617-693-4036 -------------------------------------- Jochen Wiedmann <jochen.wiedmann@freenet.de> Sent by: xmlschema-dev-request@w3.org 08/21/2004 03:47 PM To: xmlschema-dev@w3.org cc: (bcc: Noah Mendelsohn/Cambridge/IBM) Subject: Implementing xs:include for a schema without targetNamespace Hi, if I have an XML schema with target namespace, that includes another instance of XML schema without target namespace, then the SPEC requires, that the included schema be converted to a schema with the target namespace of the including schema. My problem is, how to implement this in a schema processor. The basic approach would of course be, to load the schema, convert all references to the target namespace, and be done. However, IMO this is not sufficient, because the schema might contain additional references. For example, consider a language extending XML schema by using the xs:appinfo elements, like JAXB (http://java.sun.com/xml/jaxb/) does: It is quite possible, that attributes below xs:appinfo contains other references, that my schema processor doesn't know about. My understanding is, that these should be converted too. Thus, I have a different idea, which I would like to discuss: The schema processor is iun fact a SAX parser. As such, it receives SAX events, in particular public void startElement(String pURI, String pLocalName, String pQName, Attributes pAttrs); public void endElement(String pURI, String pLocalName, String pQName); public void startPrefixMapping(String pPrefix, String pURI); The idea is, to map all URI's in the above SAX events from the "" (the absent namespace in SAX) to the desired target namespace. Thoughts? Regards, Jochen -- http://lilypie.com/baby1/050423/1/5/1/+1
Received on Monday, 23 August 2004 13:32:58 UTC