更简洁/高效的 XSLT

Question

下面的 XSLT 转换如何更简洁？它可以工作，但我仍然无法以声明的方式看到问题（作为一个相对的 XSLT 新手），并且觉得这个解决方案是一个程序性的解决方案，而且相当冗长。我想看看对声明式方法有直观感觉的人如何解决/简化它？

XSLT 用于构造具有三个深度级别的垂直导航元素。导航元素根据选择的节点展开/折叠。 Css 类（活动）也会根据选择的级别而应用。

它有 2 个参数，id 和 query_string。

在它作用的 XML 中有一个特例节点“News” - 该节点的所有后代节点都具有相同的 id，因此使用 query_string 来区分它们。

这里是 XSLT

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:msxsl="urn:schemas-microsoft-com:xslt" exclude-result-prefixes="msxsl">
<xsl:output method="html" omit-xml-declaration="yes" indent="yes" />
<xsl:param name="id" select="'id:144016'"></xsl:param>
<xsl:param name="query_string" select="'year=2012&amp;month=12'"/>

<xsl:template match="/">
<xsl:choose>
  <xsl:when test="//siteMapNode[@id=$id and @query_string=$query_string]"> 
    <xsl:apply-templates select="//siteMapNode[@id=$id and @query_string=$query_string]/ancestor-or-self::*[@depth=1]" />
  </xsl:when>
  <xsl:when test="//siteMapNode[@id=$id]/ancestor::*[@depth=1]">
    <xsl:apply-templates select="//siteMapNode[@id=$id]/ancestor-or-self::*[@depth=1]" />
  </xsl:when>
  <xsl:otherwise>
    <xsl:apply-templates select="//siteMapNode[@id=$id]" />
  </xsl:otherwise>
</xsl:choose>
</xsl:template>

<xsl:template match="siteMapNode/siteMapNode/siteMapNode">
<xsl:variable name="matchidandyearpartofquery" select="count(self::node()[@id=$id and @query_string=substring($query_string, 1, 9)])" />
<xsl:variable name="matchid" select="count(self::node()[@id=$id])" />    
<xsl:variable name="matchdescendentid" select="count(self::node()//*[@id=$id and @query_string=substring($query_string, 1, 9)])" />
<li>
  <xsl:if test="$matchidandyearpartofquery &gt; 0 or $matchdescendentid &gt; 0">
    <xsl:attribute name="class">
      <xsl:text>active</xsl:text>
    </xsl:attribute>
  </xsl:if>
  <a>
    <xsl:attribute name="href">
      <xsl:value-of select="@url" />
    </xsl:attribute>
    <xsl:value-of select="@title" />
  </a>
<xsl:choose>
  <xsl:when test="self::node()[@id=$id and @query_string=substring($query_string, 1, 9)]">
    <xsl:if test="./*">
      <ul>
        <xsl:apply-templates select="siteMapNode">
          <xsl:sort select="@month" data-type="number" order="descending"/>
        </xsl:apply-templates>
      </ul>
    </xsl:if>
  </xsl:when>
  <xsl:when test="self::node()//*[@id=$id and @query_string=substring($query_string, 1, 9)]">
      <ul>
        <xsl:apply-templates select="siteMapNode">
          <xsl:sort select="@month" data-type="number" order="descending"/>
        </xsl:apply-templates>
      </ul>
  </xsl:when>
  <xsl:when test="self::node()[@id=$id]">
    <xsl:if test="./*">
      <xsl:if test="./*[not(@id=$id)]">
      <ul>
        <xsl:apply-templates select="siteMapNode">
          <xsl:sort select="@month" data-type="number" order="descending"/>
        </xsl:apply-templates>
      </ul>
      </xsl:if>
    </xsl:if>
  </xsl:when>
  <xsl:when test="self::node()//*[@id=$id]">
      <ul>
        <xsl:apply-templates select="siteMapNode">
          <xsl:sort select="@month" data-type="number" order="descending"/>
        </xsl:apply-templates>
      </ul>
  </xsl:when>
  <xsl:otherwise>      
  </xsl:otherwise>
</xsl:choose>
</li>
</xsl:template>

<xsl:template match="siteMapNode/siteMapNode/siteMapNode/siteMapNode">
<xsl:variable name="matchidandyearpartofquery" select="count(self::node()[@id=$id and @query_string=$query_string])" />
<xsl:variable name="matchid" select="count(self::node()[@id=$id])" />
<xsl:variable name="matchdescendentid" select="count(self::node()//*[@id=$id and @query_string=substring($query_string, 1, 9)])" />
<li>
  <xsl:if test="$matchidandyearpartofquery &gt; 0 or $matchdescendentid &gt; 0">
    <xsl:attribute name="class">
      <xsl:text>active icon-nav-left</xsl:text>
    </xsl:attribute>
  </xsl:if>
  <a>
    <xsl:attribute name="href">
      <xsl:value-of select="@url" />
    </xsl:attribute>
    <xsl:value-of select="@title" />
  </a>
<xsl:choose>
 <xsl:when test="self::node()[@id=$id and @query_string=$query_string]">
    <xsl:if test="./*">
      <ul>
        <xsl:apply-templates select="siteMapNode">
          <xsl:sort select="@month" data-type="number" order="descending"/>
        </xsl:apply-templates>
      </ul>
    </xsl:if>
  </xsl:when>
  <xsl:when test="self::node()//*[@id=$id and @query_string=substring($query_string, 1, 9)]">
      <ul>
        <xsl:apply-templates select="siteMapNode">
          <xsl:sort select="@month" data-type="number" order="descending"/>
        </xsl:apply-templates>
      </ul>
  </xsl:when>
  <xsl:when test="self::node()[@id=$id]">
    <xsl:if test="./*">
      <xsl:if test="./*[not(@id=$id)]">
      <ul>
        <xsl:apply-templates select="siteMapNode">
          <xsl:sort select="@month" data-type="number" order="descending"/>
        </xsl:apply-templates>
      </ul>
      </xsl:if>
    </xsl:if>
  </xsl:when>
  <xsl:otherwise>    
  </xsl:otherwise>
</xsl:choose>
</li>
</xsl:template>

 <xsl:template match="siteMapNode/siteMapNode/siteMapNode/siteMapNode/siteMapNode">
<xsl:variable name="matchidandyearpartofquery" select="count(self::node()[@id=$id and @query_string=$query_string])" />
<li>
  <xsl:if test="$matchidandyearpartofquery &gt; 0">
    <xsl:attribute name="class">
      <xsl:text>active icon-nav-left</xsl:text>
    </xsl:attribute>
  </xsl:if>
  <a>
    <xsl:attribute name="href">
      <xsl:value-of select="@url" />
    </xsl:attribute>
    <xsl:value-of select="@title" />
  </a>
</li>
</xsl:template>
</xsl:stylesheet>

还有一些示例 XML 输入

<siteMapNode id="id:144037" title="Home" url="index.jsp" depth="0" show_in_top="Yes" show_in_footer="No" use_as_default="No" query_string="" month="" year="">
  <siteMapNode id="id:144037" title="Home" url="index.jsp" depth="1" show_in_top="Yes" show_in_footer="No" use_as_default="No" query_string="" month="" year="" />
  <siteMapNode id="id:144513" title="Company" url="our-company/index.jsp" depth="1" show_in_top="Yes" show_in_footer="No" use_as_default="No" query_string="" month="" year="">
    <siteMapNode id="id:144615" title="At a glance" url="our-company/at-a-glance.jsp" depth="2" show_in_top="No" show_in_footer="No" use_as_default="No" query_string="" month="" year="" />
    <siteMapNode id="id:144005" title="Our Brands" url="our-company/our-brands.jsp" depth="2" show_in_top="No" show_in_footer="No" use_as_default="No" query_string="" month="" year="" />
    <siteMapNode id="id:144629" title="Our Products" url="our-company/our-products.jsp" depth="2" show_in_top="No" show_in_footer="No" use_as_default="No" query_string="" month="" year="" />
    <siteMapNode id="id:144638" title="Our Global Purpose" url="our-company/our-global-purpose.jsp" depth="2" show_in_top="No" show_in_footer="No" use_as_default="No" query_string="" month="" year="" />
    <siteMapNode id="id:144002" title="Company History" url="our-company/company-history.jsp" depth="2" show_in_top="No" show_in_footer="No" use_as_default="No" query_string="" month="" year="" />
    <siteMapNode id="id:144003" title="Leadership" url="our-company/leadership.jsp" depth="2" show_in_top="No" show_in_footer="No" use_as_default="No" query_string="" month="" year="" />
  </siteMapNode>
  <siteMapNode id="id:144016" title="News" url="news-press/newslisting.jsp" depth="1" show_in_top="Yes" show_in_footer="No" use_as_default="No" query_string="" month="" year="">
    <siteMapNode id="id:144016" title="2012 Archive" url="news-press/newslisting.jsp?year=2012" depth="2" show_in_top="No" show_in_footer="No" use_as_default="No" query_string="year=2012" month="" year="2012">
      <siteMapNode id="id:144016" title="December" url="news-press/newslisting.jsp?year=2012&amp;month=12" depth="3" show_in_top="No" show_in_footer="No" use_as_default="No" query_string="year=2012&amp;month=12" month="12" year="2012" />
      <siteMapNode id="id:144016" title="April" url="news-press/newslisting.jsp?year=2012&amp;month=4" depth="3" show_in_top="No" show_in_footer="No" use_as_default="No" query_string="year=2012&amp;month=4" month="4" year="2012" />
    </siteMapNode>
    <siteMapNode id="id:144016" title="2013 Archive" url="news-press/newslisting.jsp" depth="2" show_in_top="No" show_in_footer="No" use_as_default="No" query_string="year=2013" month="" year=""/>
  </siteMapNode>
</siteMapNode>

这是预期输出 HTML 的示例（此处，从新闻部分中选择了 2012 年 12 月）

<li class="active"><a href="news-press/newslisting.jsp?year=2012">2012 Archive</a>
  <ul>
    <li class="active icon-nav-left"><a href="news-press/newslisting.jsp?year=2012&amp;month=12">December</a></li>
    <li><a href="news-press/newslisting.jsp?year=2012&amp;month=4">April</a></li>
  </ul>
</li>
<li><a href="news-press/newslisting.jsp">2013 Archive</a></li>

Answer 1

这是我的解决方案，希望对 cme​​ts 有所帮助。它适用于您的示例，但您可能有更具体的要求，这没有考虑到。不过，我希望它对你有用。

以下 XSLT 样式表：

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="html"/>

  <xsl:param name="id" select="'id:144016'"></xsl:param>
  <xsl:param name="query_string" select="'year=2012&amp;month=12'"/>

  <!-- Match the siteMapNode element at depth 1 with the specified id. Just apply 
       templates to its children. -->
  <xsl:template match="siteMapNode[@id=$id and @depth='1']"
        priority="5">
    <xsl:apply-templates select="node()|@*"/>
  </xsl:template>

  <!-- Match the siteMapNode element with the specified id that partially match the 
       query string. These will have child elements so apply templates and keep
       going. -->
  <xsl:template match="siteMapNode[@id=$id and contains($query_string, @query_string)]"
        priority="1">
    <li class="active">
      <xsl:call-template name="anchor"/>
      <ul>
    <xsl:apply-templates select="node()|@*"/>
      </ul>
    </li>
  </xsl:template>

  <!-- Match the siteMapNode element with the specified id that completely match the 
       query string. -->
  <xsl:template match="siteMapNode[@id=$id and $query_string=@query_string]"
        priority="10">
    <li class="active icon-nav-left">
      <xsl:call-template name="anchor"/>
    </li>
  </xsl:template>

  <!-- Match the remaining siteMapNode elements with the specified id.
       This template has the default priority of 0.5. -->
  <xsl:template match="siteMapNode[@id=$id]">
    <li>
      <xsl:call-template name="anchor"/>
    </li>
  </xsl:template>

  <!-- The anchor element we output is common, so put it into a template we can call. -->
  <xsl:template name="anchor">
      <a href="{@url}">
    <xsl:value-of select="@title"/>
      </a>
  </xsl:template>

  <!-- The built-in template for elements and the root node is already doing what we want, 
       so we don't need to include it explicitly. It's below, commented out, for 
       reference. -->
<!--  <xsl:template match="*|/">
    <xsl:apply-templates/>
  </xsl:template>-->

  <!-- Don't want to output text or attribute nodes unless we explicitly say so, so we 
       need to override the built-in templates for these. -->
  <xsl:template match="text()|@*"/>

</xsl:stylesheet>

在应用于您的示例输入 XML 时提供以下输出：

<li class="active"><a href="news-press/newslisting.jsp?year=2012">2012 Archive</a><ul>
      <li class="active icon-nav-left"><a href="news-press/newslisting.jsp?year=2012&amp;month=12">December</a></li>
      <li><a href="news-press/newslisting.jsp?year=2012&amp;month=4">April</a></li>
   </ul>
</li>
<li><a href="news-press/newslisting.jsp">2013 Archive</a></li>