用于计算特定子树中叶节点的简洁表达式 [英] Concise expression for counting leaf nodes in specific subtrees

问题描述

在我尝试回答问题XSLT - 棘手的转换时，我遇到了以下任务:><块引用>

对于每个标签 计算第二个叶子节点的数量 子标签.

将叶节点"定义为一个 标签，该标签没有其他 标签作为子标签.不过，它可能有其他标签作为孩子.

我最终得到了两个表达式:

<xsl:variable name="grandchildren_and_below" select="count(MMM[2]//MMM[count(MMM) = 0])"/>

第一个计算第二个孩子的叶子，第二个计算第二个孩子的所有祖先.我无法将这两个组合成一个表达式(除了我必须做的明显求和 :-) ).不知何故，我无法使节点数组索引选择器 [2]、附加条件 count(MMM) = 0 和祖先路径 `//' 适合相同的表达式.

那么，有没有更简洁(可能更优雅)的方式来编写这个表达式?

非常感谢！

为了测试，你可以使用这个输入文件:

<MMM><MMM><MMM><MMM/><MMM/></MMM><MMM><MMM/><MMM><MMM/></MMM></MMM></MMM><MMM><MMM/></MMM></MMM>

以及以下 XSLT 表:

<xsl:样式表版本=1.0"xmlns:xsl="http://www.w3.org/1999/XSL/Transform"><xsl:output method="xml" encoding="ISO-8859-1" indent="yes"/><xsl:template match="MMM"><xsl:variable name="just_children" select="count(MMM[position() = 2 and count(MMM) = 0])"/><xsl:variable name="grandchildren_and_below" select="count(MMM[2]//MMM[count(MMM) = 0])"/><MMM just_children="{$just_children}" grandchildren_and_below="{$grandchildren_and_below}"><xsl:apply-templates/></MMM></xsl:模板></xsl:stylesheet>

解决方案

你的 just_children 变量可以这样写:

您的 grandchildren_and_below 变量可以写成这样:

要将它们合二为一，您可以使用后代或自我轴，就像这样

In my attempt to answer question XSLT - Tricky Transformation I came across the following task:

For each tag <MMM> count the number of leaf nodes in the second <MMM> child tag.

Define "leaf node" as an <MMM> tag that does not have other <MMM> tags as children. It may have other tags as children, though.

I ended up with two expressions:

<xsl:variable name="just_children" select="count(MMM[position() = 2 and count(MMM) = 0])"/>
<xsl:variable name="grandchildren_and_below" select="count(MMM[2]//MMM[count(MMM) = 0])"/>

The first one counts the leafs in the second child, the second one in all ancestors of the second child. I was not able to combine these two into one expression (except for the obvious summing which I have to do :-) ). Somehow I cannot make the node array index selector [2], the additional condition count(MMM) = 0, and the ancestor path `//' fit into the same expression.

So, is there more a concise (and probably more elegant) way to write this expression?

Thanks a lot!

For testing you can use this input file:

<?xml version="1.0" encoding="ISO-8859-1"?>
<MMM>
  <MMM>
    <MMM>
      <MMM/>
      <MMM/>
    </MMM>    
    <MMM>
      <MMM/>
      <MMM>
        <MMM/>
      </MMM>
    </MMM>
  </MMM>
  <MMM>
    <MMM/>
  </MMM>
</MMM>

and the following XSLT sheet:

<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet 
    version="1.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:output method="xml" encoding="ISO-8859-1" indent="yes"/>

  <xsl:template match="MMM">
    <xsl:variable name="just_children" select="count(MMM[position() = 2 and count(MMM) = 0])"/>
    <xsl:variable name="grandchildren_and_below" select="count(MMM[2]//MMM[count(MMM) = 0])"/>
    <MMM just_children="{$just_children}" grandchildren_and_below="{$grandchildren_and_below}">
      <xsl:apply-templates/>
    </MMM>    
  </xsl:template>
</xsl:stylesheet>

解决方案

Your just_children variable could be written as this:

<xsl:variable name="just_children" select="count(MMM[2][not(MMM)])"/>

And your grandchildren_and_below variable could be written as this:

<xsl:variable name="grandchildren_and_below" select="count(MMM[2]//MMM[not(MMM)])"/>

To put them both together as one, you could use the descendant-or-self axes, like so

<xsl:variable name="all" select="count(MMM[2]//descendant-or-self::MMM[not(MMM)])"/>

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