替代.NET中的XPath id()

Question

我有以下XML文档:

<text xmlns:its="http://www.w3.org/2005/11/its" >
 <its:rules version="2.0">
  <its:termRule selector="//term" term="yes" termInfoPointer="id(@def)"/>
 </its:rules>
 <p>We may define <term def="TDPV">discoursal point of view</term>
 as <gloss xml:id="TDPV">the relationship, expressed through discourse
  structure, between the implied author or some other addresser,
  and the fiction.</gloss>
 </p>
</text>

termInfoPointer是一个指向<gloss xml:id="TDPV">元素的XPath表达式.

我使用LINQ-to-XML来选择它.

XElement term = ...;
object value = term.XPathEvaluate("id(@def)");

我得到以下异常: System.NotSupportedException: This XPathNavigator does not support IDs.

我找不到解决这个问题的方法,所以我尝试id()用其他表达式替换:

//*[@xml:id='TDPV'] // works, but I need to use @def

//*[@xml:id=@def]
//*[@xml:id=@def/text()]
//*[@xml:id=self::node()/@def/text()]

但这些都不起作用.

有没有办法id()用另一个表达式实现或替换它？

我更喜欢不涉及替换id()另一个表达式的解决方案/解决方法,因为这个表达式可能是复杂的id(@def) | id(//*[@attr="(id(@abc()))))))"]).

Answer 1

如果def保证属性仅在XMLdocument中出现一次,请使用:

//*[@xml:id = //@def]

如果可能存在不同的def属性,那么您需要提供一个XPath表达式,def在您的案例中精确选择所需的属性:

//*[@xml:id = someExpressionSelectingTheWantedDefAttribute]

基于XSLT的验证:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="/">
     <xsl:copy-of select="//*[@xml:id = //@def]"/>
 </xsl:template>
</xsl:stylesheet>

在提供的XML文档上应用此转换时:

<text xmlns:its="http://www.w3.org/2005/11/its" >
 <its:rules version="2.0">
  <its:termRule selector="//term" term="yes" termInfoPointer="id(@def)"/>
 </its:rules>
 <p>We may define <term def="TDPV">discoursal point of view</term>
 as <gloss xml:id="TDPV">the relationship, expressed through discourse
  structure, between the implied author or some other addresser,
  and the fiction.</gloss>
 </p>
</text>

评估XPath表达式,并将此评估的结果(所选元素)复制到输出:

<gloss xmlns:its="http://www.w3.org/2005/11/its" xml:id="TDPV">the relationship, expressed through discourse
  structure, between the implied author or some other addresser,
  and the fiction.</gloss>