[xml] libxml2 does xmlSchemaValidateDoc() support xml schema extensions?

[Andy Davidson <andy_davidson apple com>]

Hi

I am using libxml2. I use xmlSchemaValidateDoc() to make sure my xml is valid. Recently we started using Extension to define new complexTypes.

The description for extensions can be found at http://www.w3.org/TR/xmlschema-0/#DerivExt  

These instance do not validate using libxml2. I am able to validate these instance using java version "1.6.0_29"

Attached is my test Zoo.xsd, and the instance I am trying to validate

Attachment: ZooRequest.xsd
Description: Binary data

    <complexType name="Animal">

        <sequence>

            <element name="name" type="string" />

        </sequence>

    </complexType>

    <complexType name="Fish">

        <complexContent>

            <extension base="zoo:Animal">

                <sequence>

                    <element name="numberOfFins" type="integer" />

                </sequence>

            </extension>

        </complexContent>

    </complexType>

My xml instance is 

<?xml version="1.0" encoding="UTF-8"?>

<zoo:cageRequest xmlns:zoo="http://www.example.org/Zoo" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

  <animal xsi:type="zoo:Fish">

    <name>Blue Fin Tuna</name>

    <numberOfFins>4</numberOfFins>

  </animal>

</zoo:cageRequest>

xmlSchemaValidateDoc() generates the following output

element animal: Schemas validity error : Element 'animal', attribute 'xsi:type': The attribute 'xsi:type' is not allowed.

element numberOfFins: Schemas validity error : Element 'numberOfFins': This element is not expected.

the error returned is  1871 for instance

xmlDebugDumpDocument() produces

DOCUMENT

version=1.0

standalone=true

  ELEMENT zoo:cageRequest

    namespace zoo href="">

    namespace xsi href="">

    ELEMENT animal

      ATTRIBUTE xsi:type

        TEXT

          content=zoo:Fish

      ELEMENT name

        TEXT

          content=Blue Fin Tuna

      ELEMENT numberOfFins

        TEXT

          content=4

(gdb) 

Do I need to tweak my validation code ? 

(this is an ObjC listing)

    

    

    const char *schemaFileNameStr = [xmlSchemaFilePath cStringUsingEncoding: NSASCIIStringEncoding];

    

    // http://www.xmlsoft.org/html/libxml-parser.html#xmlReadFile

    // second arg, null, is document encoding

    // XML_PARSE_NONET option means "Forbid network access"

    xmlDocPtr schemaDoc = xmlReadFile(schemaFileNameStr, NULL, XML_PARSE_NONET);

    NSString *errorMsgRoot = @"**** ERROR: POSXMLSchemaValidator.m createAndAddValidatorFor:, ";

    if (schemaDoc == NULL) {

        /* the schema cannot be loaded or is not well-formed */

        NSLog(@"%@ the schema: %s can not be loaded or is not well-formed", errorMsgRoot, schemaFileNameStr);

        return ret;

    }

    

    // http://www.xmlsoft.org/html/libxml-xmlschemas.html#xmlSchemaNewDocParserCtxt

    xmlSchemaParserCtxtPtr parserCtxt = xmlSchemaNewDocParserCtxt(schemaDoc);

    if (parserCtxt == NULL) {

        /* unable to create a parser context for the schema */

        xmlFreeDoc(schemaDoc);

        NSLog(@"%@ unable to create a parser context for schema %s", errorMsgRoot, schemaFileNameStr);

        return ret;

    }

    

    // http://www.xmlsoft.org/html/libxml-xmlschemas.html#xmlSchemaParse

    xmlSchemaPtr schema = xmlSchemaParse(parserCtxt);

    if (schema == NULL) {

        /* the schema itself is not valid */

        xmlSchemaFreeParserCtxt(parserCtxt);

        xmlFreeDoc(schemaDoc);

        NSLog(@"%@ the schema %s is not valid", errorMsgRoot, schemaFileNameStr);

        return ret;

    }

    

    // http://www.xmlsoft.org/html/libxml-xmlschemas.html#xmlSchemaNewValidCtxt

    xmlSchemaValidCtxtPtr validCtxt = xmlSchemaNewValidCtxt(schema);

    if (validCtxt == NULL) {

        /* unable to create a validation context for the schema */

        xmlSchemaFree(schema);

        xmlSchemaFreeParserCtxt(parserCtxt);

        xmlFreeDoc(schemaDoc);

        NSLog(@"%@ unable to validation context for schema %s", errorMsgRoot, schemaFileNameStr);

        return ret; 

    }

    

    //xmlSchemaFree(schema); causes crash when we try to use validCtxt

    xmlSchemaFreeParserCtxt(parserCtxt);

    xmlFreeDoc(schemaDoc);

    

    // http://www.xmlsoft.org/html/libxml-xmlschemas.html#xmlSchemaValidateDoc

    int error = xmlSchemaValidateDoc(validCtxt.validCtxt, doc);             

    if (error == 0) {

        NSLog(@"document is a valid instance of %@", schemaFileName);

        ret = YES;

    } 

    

Is this a bug?

thanks in advance

Andy