schemaLocation question

[Peter A. Volchek]

I have the question related to "schemaLocation" attribute processing. As I noticed in your code, when parser meeths the schemaLocation attribute with the uri that was already defined previously it just gets the schema grammar from cache and uses it.   This causes the trouble when validating the following instance document:   a.xml ----------------------------------------------------------------------------- <ns:A xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"       xmlns:ns="http://www.sample.com"       xsi:schemaLocation="http://www.sample.com sch1.xsd">   <ns:B xsi:schemaLocation="http://www.sample.com sch2.xsd">Hello</ns:B> </ns:A> -----------------------------------------------------------------------------   In this document the element A is declared in in schema sch1.xsd, and element B in sch2.xsd as follows:   sch1.xsd ----------------------------------------------------------------------------- <?xml version="1.0"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"            targetNamespace="http://www.sample.com">     <xs:element name="A">     <xs:complexType>       <xs:sequence>           <xs:any namespace="http://www.sample.com" minOccurs="1" maxOccurs="unbounded"/>       </xs:sequence>     </xs:complexType>   </xs:element>   </xs:schema> -----------------------------------------------------------------------------     sch2.xsd ----------------------------------------------------------------------------- <?xml version="1.0"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"            targetNamespace="http://www.sample.com">     <xs:element name="B" type="xs:string"/>   </xs:schema> -----------------------------------------------------------------------------   Now, if you parse with DOMPrint sample you'll get the following error:   > DOMPrint.exe -v=always -n -s a.xml Error at file "a.xml", line 5, column 61    Message: Unknown element 'ns:B'   THe reason is that parser ignores the second schemaLocation attribute, meaning that the grammar already exists for it in cache. Is this expected behaviour? What does XMLSchema rec. says about it ?   Peter A. Volchek