元素序列的XSD中的复杂规则

Question

在我的XML中，我有6个元素X1、X2、X3、X4、X5和X6。规则如下：

X1后面必须跟X2

X2后面必须跟X3

X3后面必须跟X4

X4后面必须跟X2、X3、X4或X5

X5后面必须跟X6

X6后面可以跟X2、X3、X4、X5或X6

我正在尝试为此定义一个XSD。有可能吗？我使用sequence、minOccur和maxOccur尝试了几种方法，但都不起作用。有什么想法可以让我试试吗？

Answer 1

XML Schema 1.0无法处理这种情况。另一方面，Schematron直接转换您的约束，请参阅下面的工作/测试的Schematron模式：

<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://purl.oclc.org/dsdl/schematron">
  <pattern>
    <rule context="X1">
      <assert test="following-sibling::*[1][self::X2]">
        X1 must be followed by X2
      </assert>
    </rule>
    <rule context="X2">
      <assert test="following-sibling::*[1][self::X3]">
        X2 must be followed by X3
      </assert>
    </rule>
    <rule context="X3">
      <assert test="following-sibling::*[1][self::X4]">
        X3 must be followed by X4
      </assert>
    </rule>
    <rule context="X4">
      <assert test="following-sibling::*[1][self::X2 or self::X3 or self::X4 or self::X5]">
        X4 must be followed by X2, X3, X4 or X5
      </assert>
    </rule>
    <rule context="X5">
      <assert test="following-sibling::*[1][self::X6]">
        X5 must be followed by X6
      </assert>
    </rule>
    <rule context="X6">
      <assert test="not(following-sibling::*) or following-sibling::*[1][self::X2 or self::X3 or self::X4 or self::X5 or self::X6]">
        X6 can be followed by X2, X3, X4, X5 or X6
      </assert>
    </rule>
  </pattern>
</schema>

XML Schema1.1将添加断言支持，但这对断言XPath应用的范围有一些限制-您需要将断言放在X1..X6的父元素上。

还要注意，Schematron规则可以嵌入在xs:annotation/xs:appinfo中的XML Schema中，您应该能够同时针对XML Schema和嵌入的Schematron规则进行验证。

在操作评论之后跟进

嵌入上述Schematron规则的XML Schema如下所示。这是一个定义可以包含X1..X6的元素测试的示例。

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:sch="http://purl.oclc.org/dsdl/schematron">
  <xs:annotation>
    <xs:appinfo>
      <sch:title>Sample embedded Schematron rules</sch:title>
    </xs:appinfo>
  </xs:annotation>
  <xs:element name="test">
    <xs:annotation>
      <xs:appinfo>
        <sch:pattern>
          <sch:rule context="X1">
            <sch:assert test="following-sibling::*[1][self::X2]"> X1 must be followed by X2 </sch:assert>
          </sch:rule>
          <sch:rule context="X2">
            <sch:assert test="following-sibling::*[1][self::X3]"> X2 must be followed by X3 </sch:assert>
          </sch:rule>
          <sch:rule context="X3">
            <sch:assert test="following-sibling::*[1][self::X4]"> X3 must be followed by X4 </sch:assert>
          </sch:rule>
          <sch:rule context="X4">
            <sch:assert test="following-sibling::*[1][self::X2 or self::X3 or self::X4 or self::X5]"> X4
              must be followed by X2, X3, X4 or X5 </sch:assert>
          </sch:rule>
          <sch:rule context="X5">
            <sch:assert test="following-sibling::*[1][self::X6]"> X5 must be followed by X6 </sch:assert>
          </sch:rule>
          <sch:rule context="X6">
            <sch:assert
              test="not(following-sibling::*) or following-sibling::*[1][self::X2 or self::X3 or self::X4 or self::X5 or self::X6]"
              > X6 can be followed by X2, X3, X4, X5 or X6 </sch:assert>
          </sch:rule>
        </sch:pattern>
      </xs:appinfo>
    </xs:annotation>
    <xs:complexType>
      <xs:choice maxOccurs="unbounded">
        <xs:element ref="X1"/>
        <xs:element ref="X2"/>
        <xs:element ref="X3"/>
        <xs:element ref="X4"/>
        <xs:element ref="X5"/>
        <xs:element ref="X6"/>
      </xs:choice>
    </xs:complexType>
  </xs:element>

  <xs:element name="X1"/>
  <xs:element name="X2"/>
  <xs:element name="X3"/>
  <xs:element name="X4"/>
  <xs:element name="X5"/>
  <xs:element name="X6"/>
</xs:schema>

实例文档可能如下所示：

<?oxygen SCHSchema="test.xsd"?>
<test xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:noNamespaceSchemaLocation="test.xsd">
  <X1/>
  <X2/>
  <X3/>
  <X4/>
  <X4/>
  <X3/>
  <X4/>
  <X5/>
  <X6/>
  <X4/>
  <X5/>
  <X6/>
</test>

使用oXygen XML编辑器对上述内容进行了测试。该实例还将XML Schema与处理指令相关联，以告诉oXygen该模式包含嵌入的Schematron规则。验证是根据XML Schema和Schematron规则执行的。

Answer 2

无论如何，这里尝试了一种解决方案，假设X6可以是终端项目，而"OverallSequence“是基本元素。

​

<xs:complexType name="OverallSequence">
  <xs:group  ref="firstItem" />
</xs:complexType>

<xs:group name="sixthChoice">
  <xs:choice>
    <xs:group  ref="secondItem" />
    <xs:group  ref="thirdItem" />
    <xs:group  ref="fourthItem" />
    <xs:group  ref="fifthItem" />
    <xs:group  ref="sixthItem" />
  </xs:choice>
</xs:group>

<xs:group name="sixthItem">
  <xs:sequence>
    <xs:element name="X6" type="xs:string" />
    <xs:group    ref="sixthChoice" minOccurs="0" >
  </xs:sequence>
</xs:group>

<xs:group name="fifthItem">
  <xs:sequence>
    <xs:element name="X5"  type="xs:string" />
    <xs:group    ref="sixthItem" />
  </xs:sequence>
</xs:group>

<xs:group name="fourthChoice">
  <xs:choice>
    <xs:group  ref="secondItem" />
    <xs:group  ref="thirdItem" />
    <xs:group  ref="fourthItem" />
  </xs:choice>
</xs:group>

<xs:group name="fourthItem" />
  <xs:sequence>
    <xs:element name="X4" type="xs:string" />
    <xs:group    ref="fourthChoice" minOccurs="0" >
    <xs:group    ref="fifthItem" />
  </xs:sequence>
</xs:group>

<xs:group name="thirdItem" />
  <xs:sequence>
    <xs:element name="X3" type="xs:string" />
    <xs:group    ref="fourthItem">
  </xs:sequence>
</xs:group>

<xs:group name="secondItem" />
  <xs:sequence>
    <xs:element name="X2" type="xs:string" />
    <xs:group    ref="thirdItem">
  </xs:sequence>
</xs:group>

<xs:group name="firstItem" />
  <xs:sequence>
    <xs:element name="X1" type="xs:string" />
    <xs:group    ref="secondItem">
  </xs:sequence>
</xs:group>