XML / XSD-如何在其自身中递归引用complexType？

Question

My question is very similar to What xsd will let an element have itself as a sub element infinitely? .

What I want to do is utilize an XML structure that is able to create a Skeleton within XML. The XML will have a top level complexType that includes a recursive list of Bone complexTypes that include their own attributes and element data.

The XML I am using is here:

<SkeletalMapping xmlns="test" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="test SkeletalDefinition.xsd">

<Skeleton sourceSkeleton="Max" targetSkeleton="UDK" version="1.0">
    <Bone name="Origin" target="ROOT">
        <PivotPoint x="0.0" y="0.0" z="0.0" />
        <Bone name="UpperBody" target="SPINE">
            <PivotPoint x="0.0" y="0.033" z="0.438" />
            <Bone name="Head" target="HEAD">
                <PivotPoint x="0.0" y="0.006" z="0.667" />
            </Bone>
            <Bone name="RightArm" target="RIGHT_ARM">
                <PivotPoint x="-0.203" y="0.05" z="0.477" />
                <Bone name="LRightHand" target="RIGHT_HAND">
                    <PivotPoint x="-0.586" y="0.074" z="0.067" />
                </Bone> <!-- LeftHand -->
            </Bone> <!-- LeftArm -->
            <Bone name="LeftArm" target="LEFT_ARM">
                <PivotPoint x="0.203" y="0.05" z="0.477" />
                <Bone name="LeftHand" target="LEFT_HAND">
                    <PivotPoint x="0.587" y="0.074" z="0.066" />
                </Bone> <!-- LeftHand -->
            </Bone> <!-- LeftArm -->
        </Bone> <!-- UpperBody -->
        <Bone name="RightLeg" target="RIGHT_LEG">
            <PivotPoint x="-0.14" y="-0.019" z="-0.467" />
            <Bone name="RightFoot" target="RIGHT_FOOT">
                <PivotPoint x="-0.17" y="0.083" z="-0.889" />
            </Bone> <!-- RightFoot -->
        </Bone> <!-- RightLeg -->
        <Bone name="LeftLeg" target="LEFT_LEG">
            <PivotPoint x="0.14" y="-0.019" z="-0.467" />
            <Bone name="LeftFoot" target="LEFT_FOOT">
                <PivotPoint x="0.17" y="0.083" z="-0.889" />
            </Bone> <!-- LegFoot -->
        </Bone> <!-- LeftLeg -->
    </Bone> <!-- Origin -->
</Skeleton>

The XSD That I am using is:

<?xml version="1.0" encoding="utf-8" ?>
<xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">

    <xs:complexType name="Vec3">
        <xs:attribute name="x" type="xs:float"/>
        <xs:attribute name="y" type="xs:float"/>
        <xs:attribute name="z" type="xs:float"/>
    </xs:complexType>

    <xs:element name="Bone">
        <xs:complexType mixed="true">
            <xs:sequence>
                <xs:element ref="Bone" minOccurs="0" maxOccurs="unbounded"/>
            </xs:sequence>
            <xs:element name="PivotPoint" type="Vec3" minOccurs="0" maxOccurs="1"/>
            <xs:attribute name="name" type="xsd:string" use="required"/>
            <xs:attribute name="target" type="xsd:string" />
        </xs:complexType>
    </xs:element>

    <xs:element name="Skeleton">
        <xs:complexType>
            <xs:sequence>
                <xs:element ref="Bone" minOccurs="0" maxOccurs="unbounded"/>
            </xs:sequence>
            <xs:attribute name="sourceSkeleton" type="xs:string" />
            <xs:attribute name="targetSkeleton" type="xs:string" />
            <xs:attribute name="version" type="xs:string" />
        </xs:complexType>
    </xs:element>

    <xs:element name="SkeletonMapping">
        <xs:complexType>
            <xs:sequence minOccurs="0" maxOccurs="unbounded">
                <xs:element ref="Skeleton"/>
            </xs:sequence>
        </xs:complexType>
</xs:element>
</xs:schema>

The Editor I am using is Notepad++ with the XML plugins. The XML and XSD Syntax passes validation, however I can't figure out why the XML Tool validation of the XSD says it is unable to parse the XML.

If anyone knows how I can fix this please let me know, as I've tried breaking the Bone inheritance from:

<Skeleton>
    <Bone>
        <Bone>
            <Bone/>
        </Bone>
    </Bone>
</Skeleton>

to

<Skeleton>
    <BoneGroup>
        <Bone>
            <BoneGroup>
                <Bone>
                    <BoneGroup>
                        <Bone/>
                    </BoneGroup>
                </Bone>
            </BoneGroup>
        </Bone>
    </BoneGroup>
</Skeleton>

, for which I created a new element BoneGroup that had a ref to Bone, and Bone had a ref to BoneGroup, but that didn't work out any better.

Answer 1

You XML Schema file is invalid. Firstly, change the xsd: alias with xs: for those two attributes, since xs: is the alias you assigned for the XSD namespace. Then take the PivotPoint and put it first item in the sequence it is under now.

You then have to work on either the XSD or the XML to agree on what the top element name should be: SkeletalMapping or SkeletonMapping.

Then you need to fix the XML namespace; your XSD has no target namespace whereas your XML defines the default namespace as "test"; so you either add the targetNamespace and default namespace in your XSD file to be "test" or you remove the xmlns="test" in your XML file; if you go with the latter, please make sure you also change the xsi:schemaLocation to xsi:noNamespaceSchemaLocation.

I don't want to bloat the response by reposting the corrected files; if you're still having troubles, please let me know and I'll attach a link with the zipped files. I did test the corrected ones and they work fine with my tooling.