XSLT, 2nd Edition

Name

<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 Attribute

test

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

[1.0] XSLT section 9.1, “Conditional Processing with xsl:if.”

[2.0] XSLT section 8.1, “Conditional Processing with xsl:if.”

Example

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

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

  <xsl:output method="text"/>

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

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