XSD problem with complexType set abstract="true"

Question

Thank you! @Yitzhak Khabinsky I copy a small example as below:

In XSD file defined as blow:

<?xml version="1.0"?>
<xs:schema
    attributeFormDefault="unqualified"
    elementFormDefault="qualified"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns:vc="http://www.w3.org/2007/XMLSchema-versioning"
    vc:minVersion="1.1"
>   
    <xs:element name="CalculationProcess">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="CalculationStep" type="CalculationStepType" minOccurs="1" maxOccurs="unbounded" />
            </xs:sequence>
        </xs:complexType>
        <xs:unique name="UniqueId">
            <xs:selector xpath="CalculationStep"/>
            <xs:field xpath="@Id" />
        </xs:unique>
    </xs:element>

    <xs:complexType name="CalculationStepType">
        <xs:sequence>
            <xs:element name="Parameter">
                <xs:complexType>
                    <xs:all>
                        <xs:element name="AdditionalData" type="AddData" minOccurs="0">
                            <xs:alternative test="@Type = 'Woodham'" type="AddDataWoodham"/>
                        </xs:element>
                    </xs:all>
                </xs:complexType>
            </xs:element>
        </xs:sequence>
        <xs:attribute name="Id" use="required" inheritable="true">
            <xs:simpleType>
                <xs:restriction base="xs:integer">
                    <xs:minInclusive value="0"></xs:minInclusive>
                </xs:restriction>
            </xs:simpleType>
        </xs:attribute>
        <xs:attribute name="Name" type="xs:string" use="required" inheritable="true" />
        <xs:attribute name="Type" type="TCalculationStepType" use="required" />
        <xs:attribute name="InputCount" type="xs:integer" use="required" />
        <xs:attribute name="OutputCount" type="xs:integer" use="required" />
        <!-- StreamId must > 0 -->
        <xs:attribute name="StreamId" use="required" >
            <xs:simpleType>
                <xs:restriction base="xs:integer">
                    <xs:minInclusive value="1"></xs:minInclusive>
                </xs:restriction>
            </xs:simpleType>
        </xs:attribute>
    </xs:complexType>
    
    <!-- CalculationStep@Type must match one of the enumerations -->
    <xs:simpleType name="TCalculationStepType">
        <xs:restriction base="xs:string">
            <xs:enumeration value="Woodham" />
        </xs:restriction>
    </xs:simpleType>
    
    <xs:complexType name="AddData" abstract="true"/>
       
    <xs:complexType name="AddDataWoodham">
        <xs:complexContent>
            <xs:extension  base="AddData">
                <!--PhotostereoWoodham-->
                <xs:all>
                    <xs:element name="FilePath" type="xs:string" minOccurs="1" />
                    <xs:element name="ScaleFactorP" type="xs:decimal" minOccurs="1" />
                    <xs:element name="ScaleFactorQ" type="xs:decimal" minOccurs="1" />
                    <xs:element name="CalculationMethod" type="xs:integer" minOccurs="1" />
                    <xs:element name="SlantLookupSize" type="xs:integer" minOccurs="1" />
                    <xs:element name="TiltLookupSize" type="xs:integer" minOccurs="1" />
                </xs:all>
            </xs:extension >
        </xs:complexContent>
    </xs:complexType>
</xs:schema>

XML file:

<?xml version='1.0'?>
<CalculationProcess xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="ObjCalcConfig.xsd">
    <CalculationStep Id='0' Name='Woodham' Type='Woodham' InputCount='4' OutputCount='3' StreamId='1'>
        <Parameter>
            <AdditionalData>
                <FilePath>files\matrix.xml</FilePath>
                <ScaleFactorP>1.5</ScaleFactorP>
                <ScaleFactorQ>1.5</ScaleFactorQ>
                <CalculationMethod>2</CalculationMethod>
                <SlantLookupSize>25</SlantLookupSize>
                <TiltLookupSize>72</TiltLookupSize>
            </AdditionalData>
        </Parameter>
    </CalculationStep>
</CalculationProcess>

But I get a error: enter image description here

I don't know where is the problem, could someone please help me to resolve this error. THANK YOU!!!

I tried do abstract="false", that doesn't work because the base element is empty...

Answer 1

I'm not sure what you are trying to achieve here.

Your type alternative rules are saying that if @Type is "Woodham", then the element should have type AddDataWoodham; if the Type attribute is absent or has any other value (which is the case for your example), then the element should have type AddData; but an element cannot have type AddData because the type is abstract. So that's clearly an error.

Your instance seems to conform to type AddDataWoodham, but it isn't being validated against that type, because it doesn't have a Type attribute with value Woodham.