XSL技术实现：从逗号分隔字符串创建可遍历数组

Hey there! Let's figure out how to turn that comma-separated string into something you can loop over with <xsl:for-each> in XSL. The solution depends on which XSLT version you're working with, so I'll break down both common scenarios:

If you're using XSLT 2.0 or later (like 3.0), you can use the built-in tokenize() function to split the string directly into a sequence of strings—which you can iterate over right away.

Here's a complete example:

<!-- Define your original string variable -->
<xsl:variable name="string-variable" select="'hello, hello, good Evening, good evening'" />

<!-- Split the string, handling spaces around commas -->
<xsl:variable name="split-sequence" select="tokenize($string-variable, '\s*,\s*')" />

<!-- Loop through each item in the sequence -->
<xsl:for-each select="$split-sequence">
  <list-item>
    <xsl:value-of select="." />
  </list-item>
</xsl:for-each>

Quick breakdown: #

• The regex \s*,\s* matches a comma surrounded by any number of whitespace characters (spaces, tabs, etc.). This ensures you don't end up with extra spaces in your split values.
• The tokenize() function returns a sequence, so <xsl:for-each> can directly select it without extra steps.

XSLT 1.0 doesn't have a built-in tokenize() function, so we need to create a recursive template to split the string into a node set (since 1.0 works with nodes instead of sequences).

Here's how to do it:

<!-- Your original string variable -->
<xsl:variable name="string-variable" select="'hello, hello, good Evening, good evening'" />

<!-- Call the split template to generate a node set -->
<xsl:variable name="split-nodes">
  <xsl:call-template name="split-string">
    <xsl:with-param name="input" select="$string-variable" />
    <xsl:with-param name="delimiter" select="', '" /> <!-- Adjust if your delimiter has different spacing -->
  </xsl:call-template>
</xsl:variable>

<!-- Loop through the generated <item> nodes -->
<xsl:for-each select="$split-nodes/item">
  <list-item>
    <xsl:value-of select="." />
  </list-item>
</xsl:for-each>

<!-- Recursive template to split the string into nodes -->
<xsl:template name="split-string">
  <xsl:param name="input" />
  <xsl:param name="delimiter" select="', '" />
  
  <xsl:choose>
    <!-- If the input still contains the delimiter -->
    <xsl:when test="contains($input, $delimiter)">
      <!-- Extract the part before the delimiter -->
      <item>
        <xsl:value-of select="substring-before($input, $delimiter)" />
      </item>
      <!-- Recurse with the remaining part of the string -->
      <xsl:call-template name="split-string">
        <xsl:with-param name="input" select="substring-after($input, $delimiter)" />
        <xsl:with-param name="delimiter" select="$delimiter" />
      </xsl:call-template>
    </xsl:when>
    <!-- No more delimiters left—add the final item -->
    <xsl:otherwise>
      <item>
        <xsl:value-of select="$input" />
      </item>
    </xsl:otherwise>
  </xsl:choose>
</xsl:template>

Notes for XSLT 1.0: #

• If your XSLT processor supports the EXSLT str:tokenize extension, you can simplify this by using str:tokenize($string-variable, '\s*,\s*')—just add the namespace xmlns:str="http://exslt.org/strings" to your stylesheet. But not all processors support this, so the recursive template is more reliable.
• To handle leading/trailing commas or extra spaces, you can add a step to trim the input string first (using a helper template for trimming in 1.0).

内容的提问来源于stack exchange，提问作者Robertone