XSD 1.1 - 子元素上的替代测试Xpath

我试图使用XSD 1.1框架来测试当前范围元素的子元素是否包含属性 . 如果为true，我想要对元素进行一次模式验证，如果为false我想要另一个 .

Example XML

<!-- XML 1 -->
<GrandParent name="Sam">
    <Parent name="Kevin">
        <Child name="Kyle" id="10" dob="1989-05-02"/>
    </Parent>
</GrandParent>


<!-- XML 2 -->
<GrandParent name="Sam">
    <Parent name="Kevin" id="10" dob="1975-10-11"/>
</GrandParent>

XSD 1.1 used for above xml examples

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

  <xs:element name="GrandParent">
      <xs:complexType>
          <xs:sequence>
            <xs:element ref="Parent" />
          </xs:sequence>
          <xs:attribute name="name" type="xs:string" use="required" />
      </xs:complexType>
  </xs:element>

  <xs:element name="Parent">
      <xs:alternative test="./Child/@id" type="ParentType1" />
      <xs:alternative                    type="ParentType2" />
  </xs:element>

  <xs:element name="Child">
      <xs:complexType>
          <xs:attribute name="name" type="xs:string" use="required" />
          <xs:attribute name="id" type="xs:integer" use="required" />
          <xs:attribute name="dob" type="xs:date" use="required" />
      </xs:complexType>
  </xs:element>

  <xs:complexType name="ParentType1">
      <xs:sequence>
          <xs:element ref="Child" />
      </xs:sequence>
      <xs:attribute name="name" type="xs:string" use="required" />
  </xs:complexType>

  <xs:complexType name="ParentType2">
      <xs:attribute name="name" type="xs:string" use="required" />
      <xs:attribute name="id" type="xs:integer" use="required" />
      <xs:attribute name="dob" type="xs:date" use="required" />
  </xs:complexType>

</xs:schema>

我正在使用Xerces xsd 1.1验证功能 XSD Validation Error

XML 1
[Error] 1:46: cvc-complex-type.4: Attribute 'id' must appear on element 'Parent'.
[Error] 1:46: cvc-complex-type.4: Attribute 'dob' must appear on element 'Parent'.
[Error] 1:100: cvc-complex-type.2.1: Element 'Parent' must have no character or element information item [children], because the type's content type is empty.

XML 2
Validates

Xpath没有尝试过一些变化，包括 //Child/@id 和 boolean(Child/@id) ，但没有快乐 . 我不关心属性的值是什么，只是它存在于子元素中 .

Update

感谢Michael Kay提供的以下答案，我重写了我的架构使用断言而不是替代品 . 这是更新的架构：

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

    <xs:element name="GrandParent">
        <xs:complexType>
            <xs:choice>
                <xs:element ref="Parent" />
            </xs:choice>
            <xs:attribute name="name" type="xs:string" use="required" />
        </xs:complexType>
    </xs:element>

    <xs:element name="Child">
        <xs:complexType>
            <xs:attribute name="name" type="xs:string"  use="required" />
            <xs:attribute name="id"   type="xs:integer" use="required" />
            <xs:attribute name="dob"  type="xs:date"    use="required" />
        </xs:complexType>
    </xs:element>

    <xs:element name="Parent">
        <xs:complexType>
            <xs:sequence>
                <xs:element ref="Child" minOccurs="0"/>
            </xs:sequence>
            <xs:attribute name="name" type="xs:string"  use="required" />
            <xs:attribute name="id"   type="xs:integer" use="optional" />
            <xs:attribute name="dob"  type="xs:date"    use="optional" />
            <xs:assert test="if (Child/@id) then not(@id or @dob) else (@id and @dob and not(Child))"/>
        </xs:complexType>
    </xs:element>

</xs:schema>

该模式似乎工作得更好，我使用以下XML测试它，所有这些都按预期通过或失败

PASS <GrandParent name="Sam"><Parent name="Kevin"><Child name="Kyle" id="10" dob="1989-05-02"/></Parent></GrandParent>
PASS <GrandParent name="Sam"><Parent name="Kevin" id="10" dob="1975-10-11"/></GrandParent>
FAIL <GrandParent name="Sam"><Parent name="Kevin" id="10"/></GrandParent>
FAIL <GrandParent name="Sam"><Parent name="Kevin" dob="1975-10-11"/></GrandParent>
FAIL <GrandParent name="Sam"><Parent name="Kevin"/></GrandParent>