<xsl:if>  
Implements an if statement. It contains a test attribute and an XSLT template. If the test attribute evaluates to the boolean value true, the XSLT template is processed. This element implements an if statement only; if you need an if-then-else statement, use the <xsl:choose> element with a single <xsl:when> and a single <xsl:otherwise>.
 
Category

Instruction
 
Required Attributes
test
The test attribute contains a boolean expression. If it evaluates to the boolean value true , then the XSLT template inside the < xsl:if > element is processed.

 
Optional Attributes

None.
 
Content

An XSLT template.
 
Appears in

<xsl:if> appears inside a template.
 
Defined in

XSLT section 9.1, Conditional Processing with xsl:if.
 
Example

We'll illustrate the <xsl:if> element with the following stylesheet:

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

  <xsl:output method="text"/>

  <xsl:variable name="newline">
<xsl:text>
</xsl:text>
  </xsl:variable>

  <xsl:template match="/">
    <xsl:value-of select="$newline"/>
    <xsl:text>Here are the odd-numbered items from the list:</xsl:text>
    <xsl:value-of select="$newline"/>
    <xsl:for-each select="list/listitem">
      <xsl:if test="(position() mod 2) = 1">
        <xsl:number format="1. "/>
        <xsl:value-of select="."/>
        <xsl:value-of select="$newline"/>
      </xsl:if>
    </xsl:for-each>
  </xsl:template>
  
</xsl:stylesheet>

This stylesheet uses the <xsl:if> element to see if a given <listitem>'s position is an odd number. If it is, we write it to the result tree. We'll test our stylesheet with this XML document:

<?xml version="1.0"?>
<list>
  <title>A few of my favorite albums</title>
  <listitem>A Love Supreme</listitem>
  <listitem>Beat Crazy</listitem>
  <listitem>Here Come the Warm Jets</listitem>
  <listitem>Kind of Blue</listitem>
  <listitem>London Calling</listitem>
  <listitem>Remain in Light</listitem>
  <listitem>The Joshua Tree</listitem>
  <listitem>The Indestructible Beat of Soweto</listitem>
</list>

When we run this transformation, here are the results:

Here are the odd-numbered items from the list:
1. A Love Supreme
3. Here Come the Warm Jets
5. London Calling
7. The Joshua Tree