XSLT - 追加同级

Question

我正在尝试使用 XSLT 将 context-param 附加为最后一个兄弟。没有共同的父元素，所以任务有点难。

我想添加以下元素：

<context-param>
    <param-name>miku</param-name>
    <param-value>kawaii</param-value>
</context-param>

作为最后一个context-param元素（例如所有context-param元素必须彼此相邻，它们不能分散在xml中的任何地方）在以下xml中：

<web-app>
  <not_interesting_element1/>
  <not_interesting_element2/>

  <context-param>
    <param-name>not_interesting_param_key1</param-name>
    <param-value>kawaii</param-value>
  </context-param>
  <context-param>
    <param-name>not_interesting_param_key2</param-name>
    <param-value>kawaii</param-value>
  </context-param>
  <context-param>
    <param-name>parameterThatsGuaranteedToBeHere</param-name>
    <param-value>someValue</param-value>
  </context-param>


  <not_interesting_element3/>
  <not_interesting_element4/>
  <!-- ... servlets, ... -->
</web-app>

结果应该是这样的：

<web-app>
  <not_interesting_element1/>
  <not_interesting_element2/>

  <context-param>
    <param-name>not_interesting_param_key1</param-name>
    <param-value>kawaii</param-value>
  </context-param>
  <context-param>
    <param-name>not_interesting_param_key2</param-name>
    <param-value>kawaii</param-value>
  </context-param>
  <context-param>
    <param-name>parameterThatsGuaranteedToBeHere</param-name>
    <param-value>someValue</param-value>
  </context-param>
  <context-param>
      <param-name>miku</param-name>
      <param-value>kawaii</param-value>
  </context-param>

  <not_interesting_element3/>
  <not_interesting_element4/>
  <!-- ... servlets, ... -->
</web-app>

请问我该怎么做？

Answer 1

这种转变：

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

 <xsl:param name="pElemToAdd">
    <context-param>
        <param-name>miku</param-name>
        <param-value>kawaii</param-value>
    </context-param>
 </xsl:param>

 <xsl:template match="node()|@*" name="identity">
     <xsl:copy>
       <xsl:apply-templates select="node()|@*"/>
     </xsl:copy>
 </xsl:template>

 <xsl:template match="context-param[last()]">
  <xsl:call-template name="identity"/>
  <xsl:copy-of select="$pElemToAdd"/>
 </xsl:template>
</xsl:stylesheet>

应用于提供的 XML 文档时：

<web-app>
    <not_interesting_element1/>
    <not_interesting_element2/>
    <context-param>
        <param-name>not_interesting_param_key1</param-name>
        <param-value>kawaii</param-value>
    </context-param>
    <context-param>
        <param-name>not_interesting_param_key2</param-name>
        <param-value>kawaii</param-value>
    </context-param>
    <context-param>
        <param-name>parameterThatsGuaranteedToBeHere</param-name>
        <param-value>someValue</param-value>
    </context-param>
    <not_interesting_element3/>
    <not_interesting_element4/>
    <!-- ... servlets, ... -->
</web-app>

产生想要的正确结果：

<web-app>
   <not_interesting_element1/>
   <not_interesting_element2/>
   <context-param>
      <param-name>not_interesting_param_key1</param-name>
      <param-value>kawaii</param-value>
   </context-param>
   <context-param>
      <param-name>not_interesting_param_key2</param-name>
      <param-value>kawaii</param-value>
   </context-param>
   <context-param>
      <param-name>parameterThatsGuaranteedToBeHere</param-name>
      <param-value>someValue</param-value>
   </context-param>
   <context-param>
      <param-name>miku</param-name>
      <param-value>kawaii</param-value>
   </context-param>
   <not_interesting_element3/>
   <not_interesting_element4/><!-- ... servlets, ... -->
</web-app>

解释：

1. 身份规则“按原样”复制每个节点。

2. 只有一个模板，覆盖身份模板。此模板匹配作为其父级子级的所有 context-param 元素的最后一个 context-param 元素。

3. 在覆盖模板中执行了两个操作；当前节点通过对身份规则的调用被复制；然后将要附加的元素复制到输出。为了方便和灵活，我们假设要附加的元素作为参数传递给转换。