XSLT <value-of>

Extracting and displaying XML data values

📝 What is <xsl:value-of>?

The <xsl:value-of> element extracts the value of an XML node and displays it in the output. It's used to select and show specific data from your XML document. 


<!-- Simple value-of example -->
<xsl:value-of select="title"/>

Understanding <value-of>

The <xsl:value-of> element is one of the most commonly used XSLT elements. It retrieves text content from XML nodes using XPath expressions and inserts it into the transformed output document.

🎯

Select Attribute

Points to the XML node 

<xsl:value-of select="name"/>
📊

XPath Expression

Navigate XML structure 

<xsl:value-of select="book/title"/>
🔤

Text Output

Displays node content 

<xsl:value-of select="@price"/>
✨

Single Value

Returns first match only 

<xsl:value-of select="item[1]"/>

🔹 Basic Example

Here's a simple example showing how to extract values from XML:

XML Data: 

<?xml version="1.0"?>
<book>
    <title>Learning XSLT</title>
    <author>John Smith</author>
    <price>29.99</price>
</book>

XSLT Template: 

<xsl:template match="book">
    <h2><xsl:value-of select="title"/></h2>
    <p>Author: <xsl:value-of select="author"/></p>
    <p>Price: $<xsl:value-of select="price"/></p>
</xsl:template>

Output:

Learning XSLT

Author: John Smith

Price: $29.99

🔹 Selecting Attributes

Use the @ symbol to select attribute values from XML elements:

XML Data: 

<product id="101" category="Electronics">
    <name>Laptop</name>
</product>

XSLT Template: 

<xsl:template match="product">
    <p>ID: <xsl:value-of select="@id"/></p>
    <p>Category: <xsl:value-of select="@category"/></p>
    <p>Name: <xsl:value-of select="name"/></p>
</xsl:template>

Output:

ID: 101

Category: Electronics

Name: Laptop

🔹 Using XPath Expressions

Navigate through nested XML structures using path expressions:

XML Data: 

<library>
    <book>
        <title>XML Basics</title>
        <author>
            <firstname>Jane</firstname>
            <lastname>Doe</lastname>
        </author>
    </book>
</library>

XSLT Template: 

<xsl:template match="library">
    <h3><xsl:value-of select="book/title"/></h3>
    <p>By: <xsl:value-of select="book/author/firstname"/> 
    <xsl:value-of select="book/author/lastname"/></p>
</xsl:template>

Output:

XML Basics

By: Jane Doe

🔹 Complete XSLT Document

Here's a full working XSLT stylesheet using value-of: 

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

<xsl:template match="/">
    <html>
    <body>
        <h1>Book Information</h1>
        <xsl:apply-templates select="book"/>
    </body>
    </html>
</xsl:template>

<xsl:template match="book">
    <div>
        <h2><xsl:value-of select="title"/></h2>
        <p><xsl:value-of select="author"/></p>
    </div>
</xsl:template>

</xsl:stylesheet>

💡 Key Points:

  • Use select attribute to specify which node to extract
  • Use @ to select attribute values
  • Returns only the first matching node if multiple exist
  • Outputs text content, not HTML tags
  • Can be combined with literal text in output

🧠 Test Your Knowledge

How do you select an attribute value in XSLT?