XSLT实现XML中sectors数组首个可映射元素匹配及兜底处理方案咨询

The issue with your original code is that <xsl:apply-templates select="sectors/sector"/> processes all sector elements, which results in multiple outputs (including the fallback sector_other for non-matching sectors). To fix this, we need to target only the first sector that matches your predefined mapping, and fall back to sector_other if no matches exist.

Here's a working XSLT implementation:

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

  <!-- Main template to generate the sectorIdentifier element -->
  <xsl:template match="/">
    <sectorIdentifier>
      <!-- Apply templates only to the FIRST sector that matches our predefined list -->
      <xsl:apply-templates select="sectors/sector[. = 'industry' or . = 'health'][1]"/>
      
      <!-- If no matching sectors exist, output the fallback value -->
      <xsl:if test="not(sectors/sector[. = 'industry' or . = 'health'])">
        <xsl:text>sector_other</xsl:text>
      </xsl:if>
    </sectorIdentifier>
  </xsl:template>

  <!-- Template for 'industry' sector -->
  <xsl:template match="sector[. = 'industry']">
    <xsl:text>sector_industry_materials</xsl:text>
  </xsl:template>

  <!-- Template for 'health' sector -->
  <xsl:template match="sector[. = 'health']">
    <xsl:text>sector_health_medical</xsl:text>
  </xsl:template>

  <!-- Optional: Add more predefined sector mappings here as needed -->
  <!-- Example:
  <xsl:template match="sector[. = 'logistique']">
    <xsl:text>sector_logistics_transport</xsl:text>
  </xsl:template>
  -->
</xsl:stylesheet>

How This Works: #

1. Target the First Match: The select="sectors/sector[. = 'industry' or . = 'health'][1]" filters sectors to only those in your predefined list, then picks the first one in the original XML order.
2. Map to Identifier: Separate templates handle each sector value, outputting the corresponding mapped string cleanly.
3. Fallback Handling: The <xsl:if> checks if there are no matching sectors at all, and outputs sector_other in that case.

Testing with Your Input: #

For your sample XML:

<sectors type="array">
 <sector>industry</sector>
 <sector>e-commerce</sector>
 <sector>logistique</sector>
</sectors>

The output will be:

<sectorIdentifier>sector_industry_materials</sectorIdentifier>

If all sectors are non-matching (e.g., e-commerce and logistique), the output becomes:

<sectorIdentifier>sector_other</sectorIdentifier>

This approach ensures you only get the first valid mapped sector, or the fallback value when no matches exist.

内容的提问来源于stack exchange，提问作者vittorio