基于XSLT按子节点排序XML：提取指定歌曲并按rank_song排序

我帮你写了一段针对性的XSLT代码，可以从你的XML文档里提取所有带rank_song的歌曲，关联对应的专辑和乐队名称，并且按排名数值升序排序。

先补全你的XML示例（方便测试） #

<?xml version='1.0' encoding='UTF-8' standalone="yes"?>
<!DOCTYPE soundvisor SYSTEM "soundvisor.dtd">
<soundvisor>
  <groups>
    <group name_g='ACDC'>
      <city>Sidney</city>
      <country>Australia</country>
      <year_born>1973</year_born>
      <albums>
        <album name_a='Back in Black'>
          <year>1980</year>
          <songs>
            <song name_s='Hells Bells'>
              <rank_song>1</rank_song>
            </song>
            <song name_s='Back in Black'>
              <rank_song>2</rank_song>
            </song>
          </songs>
        </album>
        <album name_a='Highway to Hell'>
          <year>1979</year>
          <songs>
            <song name_s='Highway to Hell'>
              <rank_song>3</rank_song>
            </song>
          </songs>
        </album>
      </albums>
    </group>
    <group name_g='Led Zeppelin'>
      <city>London</city>
      <country>UK</country>
      <year_born>1968</year_born>
      <albums>
        <album name_a='IV'>
          <year>1971</year>
          <songs>
            <song name_s='Stairway to Heaven'>
              <rank_song>1</rank_song>
            </song>
          </songs>
        </album>
      </albums>
    </group>
  </groups>
</soundvisor>

对应的XSLT代码 #

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <!-- 匹配根节点，生成输出的根标签 -->
  <xsl:template match="/soundvisor">
    <ranked_songs>
      <!-- 筛选所有带rank_song的歌曲，按排名数值升序排序 -->
      <xsl:apply-templates select="groups/group/albums/album/songs/song[rank_song]">
        <xsl:sort select="rank_song" data-type="number" order="ascending"/>
      </xsl:apply-templates>
    </ranked_songs>
  </xsl:template>

  <!-- 处理每个符合条件的歌曲节点，输出关联信息 -->
  <xsl:template match="song">
    <song_entry>
      <band_name><xsl:value-of select="../../../@name_g"/></band_name>
      <album_name><xsl:value-of select="../../@name_a"/></album_name>
      <song_name><xsl:value-of select="@name_s"/></song_name>
      <rank><xsl:value-of select="rank_song"/></rank>
    </song_entry>
  </xsl:template>

</xsl:stylesheet>

关键细节说明 #

• 过滤逻辑：用song[rank_song]确保只处理带有排名的歌曲，忽略没有rank_song节点的条目
• 排序规则：指定data-type="number"是为了避免字符串排序的坑（比如"10"不会排在"2"前面）
• 路径关联：通过相对XPath路径从歌曲节点向上回溯，获取乐队（../../../@name_g）和专辑（../../@name_a）的名称

转换后的输出结果 #

<?xml version="1.0" encoding="UTF-8"?>
<ranked_songs>
  <song_entry>
    <band_name>ACDC</band_name>
    <album_name>Back in Black</album_name>
    <song_name>Hells Bells</song_name>
    <rank>1</rank>
  </song_entry>
  <song_entry>
    <band_name>Led Zeppelin</band_name>
    <album_name>IV</album_name>
    <song_name>Stairway to Heaven</song_name>
    <rank>1</rank>
  </song_entry>
  <song_entry>
    <band_name>ACDC</band_name>
    <album_name>Back in Black</album_name>
    <song_name>Back in Black</song_name>
    <rank>2</rank>
  </song_entry>
  <song_entry>
    <band_name>ACDC</band_name>
    <album_name>Highway to Hell</album_name>
    <song_name>Highway to Hell</song_name>
    <rank>3</rank>
  </song_entry>
</ranked_songs>

内容的提问来源于stack exchange，提问作者xavier