Major Description
Say we have these two schemas:
foo.dfdl.xsd
<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:dfdl="http://www.ogf.org/dfdl/dfdl-1.0/" xmlns:dfdlx="http://www.ogf.org/dfdl/dfdl-1.0/extensions" xmlns:foo="http://example.com/" targetNamespace="http://example.com/" elementFormDefault="unqualified"> <include schemaLocation="/org/apache/daffodil/xsd/DFDLGeneralFormat.dfdl.xsd" /> <include schemaLocation="bar.dfdl.xsd" /> <annotation> <appinfo source="http://www.ogf.org/dfdl/"> <dfdl:format ref="foo:GeneralFormat" representation="binary" /> </appinfo> </annotation> <element name="foo" type="foo:NumEnums" /> </schema>
bar.dfdl.xsd
<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:dfdl="http://www.ogf.org/dfdl/dfdl-1.0/" xmlns:dfdlx="http://www.ogf.org/dfdl/dfdl-1.0/extensions" xmlns:bar="http://example.com/" targetNamespace="http://example.com/" elementFormDefault="unqualified"> <include schemaLocation="/org/apache/daffodil/xsd/DFDLGeneralFormat.dfdl.xsd" /> <annotation> <appinfo source="http://www.ogf.org/dfdl/"> <dfdl:format ref="bar:GeneralFormat" representation="binary" /> </appinfo> </annotation> <simpleType name="enum" dfdl:lengthKind="explicit" dfdl:length="1"> <restriction base="xs:int" /> </simpleType> <simpleType name="NumEnums" dfdlx:repType="bar:enum"> <restriction base="xs:string"> <enumeration value="zero" dfdlx:repValues="0"/> <enumeration value="one" dfdlx:repValues="1"/> </restriction> </simpleType> </schema>
Note that foo.dfdl.xsd and bar.dfdl.xsd use the same targetNamespace, but have different namespace prefixes.
Trying to compile this schema causes the error:
> [error] Schema Definition Error: Undefined QName prefix 'bar'
Likely what is happening is we create a quasi element in the scope foo.dfdl.xsd that has its type set to that of its dfdlx:repType property, which is "bar:enum". But in that scope, "bar:enum" doesn't make sense because the "bar" prefix isn't defined, the namespace prefix in this scope is "foo".