XSLT - <xsl:apply-templates> (with select) to <xsl:for-each>.

What is <xsl:apply-templates>?

  • <xsl:apply-templates> tells the XSLT processor:
    “Go find matching nodes (based on select) and then apply the best matching template rules I’ve defined for them.”

  • It’s template-driven, unlike <xsl:for-each>, which is more procedural.

Syntax

<xsl:apply-templates select="XPath_expression"/>

  • select defines the nodes to which templates should be applied.

  • The processor will look for <xsl:template match="..."> rules that match those nodes.

Example XML

<books>
    <book>
        <title>XML Fundamentals</title>
        <author>Alice Johnson</author>
    </book>
    <book>
        <title>XSLT in Action</title>
        <author>Bob Smith</author>
    </book>
</books>

XSLT using <xsl:apply-templates>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
    <xsl:template match="/">
        <html>
            <body>
                <h2>Book List</h2>
                <ul>
                    <!-- Apply templates to each <book> node -->
                    <xsl:apply-templates select="books/book"/>
                </ul>
            </body>
        </html>
    </xsl:template>

    <!-- Template for each book -->
    <xsl:template match="book">
        <li>
            <xsl:value-of select="title"/> - 
            <xsl:value-of select="author"/>
        </li>
    </xsl:template>
</xsl:stylesheet>

Output (HTML result)

<html>
  <body>
    <h2>Book List</h2>
    <ul>
      <li>XML Fundamentals - Alice Johnson</li>
      <li>XSLT in Action - Bob Smith</li>
    </ul>
  </body>
</html>

Difference from <xsl:for-each>

  • xsl:for-each: You write instructions directly inside the loop.

  • xsl:apply-templates: Delegates processing to matching templates, making code more modular and reusable.