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如何使用XPath选择具有最长子#text节点值的XML节点？

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在使用此查询之前，我已使用XPath选择具有最大整数id值的节点：

//somenode[not(@id <= preceding::somenode/@id) and not(@id <= following::somenode/@id)]

我希望我可以做类似的事情：

//entry[not(string-length(child::text()) <= string-length(preceding::entry/child::text())) and not(string-length(child::text()) <= string-length(following::entry/child::text()))]

但它返回一堆节点而不是一个节点 .

示例XML：

<xml>
  <entry>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</entry>
  <entry>Nam dignissim mi a massa mattis rutrum eu eget mauris.</entry>
  <entry>Ut at diam a sem scelerisque pretium nec pulvinar purus.</entry>
  <entry>Nunc in nisi nec dolor accumsan suscipit vel a quam.</entry>
  <entry>Nunc suscipit lobortis arcu, nec adipiscing libero bibendum nec.</entry>
  <entry>Aenean eget ipsum et nunc eleifend scelerisque.</entry>
  <entry>In eu magna et diam volutpat molestie.</entry>
  <entry>In volutpat luctus mi, eu laoreet orci dictum vel.</entry>
  <entry>In mattis mi nec magna sodales eu bibendum felis aliquet.</entry>
<!-- etc for 800 more lines or so -->
  <entry>Duis auctor felis id neque gravida ut auctor ipsum ullamcorper.</entry>
  <entry>Sed vel tortor mauris, et aliquet tellus.</entry>
</xml>

XPath测试：http://chris.photobooks.com/xml/default.htm?state=1o

xml xpath textnode

1 回答

  • 2

    The wanted element(s) cannot be selected with a single XPath 1.0 expression ，因为在XPath 1.0中，无法将函数应用于所有选定节点（ string-length(someNodeSet) 仅应用于此节点集的第一个节点） . 另一个原因是在XPath 1.0中，无法命名和引用范围变量 .

    In XPath 2.0 this is trivial ：

    /*/entry[not(string-length(.) &lt; /*/entry/string-length(.))]

    以上选择所有 entry 元素，其字符串值的长度为最大值 .

    /*/entry[not(string-length(.) &lt; /*/entry/string-length(.))] [1]

    以上选择了第一个（按文档顺序）这样的 entry 元素 .

    XSLT 2.0 - based verification ：

    这种转变：

    <xsl:stylesheet version="2.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

 <xsl:template match="/">
  <xsl:sequence select=
   "/*/entry[not(string-length(.) &lt; /*/entry/string-length(.))]"/>
 </xsl:template>
</xsl:stylesheet>

    when applied on the provided XML document ：

    <xml>
  <entry>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</entry>
  <entry>Nam dignissim mi a massa mattis rutrum eu eget mauris.</entry>
  <entry>Ut at diam a sem scelerisque pretium nec pulvinar purus.</entry>
  <entry>Nunc in nisi nec dolor accumsan suscipit vel a quam.</entry>
  <entry>Nunc suscipit lobortis arcu, nec adipiscing libero bibendum nec.</entry>
  <entry>Aenean eget ipsum et nunc eleifend scelerisque.</entry>
  <entry>In eu magna et diam volutpat molestie.</entry>
  <entry>In volutpat luctus mi, eu laoreet orci dictum vel.</entry>
  <entry>In mattis mi nec magna sodales eu bibendum felis aliquet.</entry>
<!-- etc for 800 more lines or so -->
  <entry>Duis auctor felis id neque gravida ut auctor ipsum ullamcorper.</entry>
  <entry>Sed vel tortor mauris, et aliquet tellus.</entry>
</xml>

    selects the entry elements (in this case only one) with the maximum string-length and outputs the selected elements ：

    <entry>Nunc suscipit lobortis arcu, nec adipiscing libero bibendum nec.</entry>
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