XSLT xsl:if

In XSLT (Extensible Stylesheet Language Transformations), the xsl:if element is used to perform conditional processing. It allows you to apply a template or process certain nodes based on a specified condition. If the condition evaluates to true, the code block within the xsl:if element is executed; otherwise, it is skipped.

The basic syntax of the xsl:if element is as follows:

<xsl:if test="condition">
  <!-- Code block to execute when the condition is true -->
</xsl:if>

In this structure:

• The test attribute of the xsl:if element specifies the XPath expression that determines the condition to be evaluated. The expression can be any valid XPath expression that results in a boolean value (true or false).
• If the test expression evaluates to true, the code block within the xsl:if element is executed. If the expression evaluates to false, the code block is skipped, and no processing occurs.

Here’s an example of using xsl:if to apply a template based on a condition:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:template match="/">
    <output>
      <xsl:if test="price &lt; 50">
        <cheap-book>
          <xsl:apply-templates select="bookstore/book[price &lt; 50]"/>
        </cheap-book>
      </xsl:if>
    </output>
  </xsl:template>

  <xsl:template match="book">
    <title><xsl:value-of select="title"/></title>
    <price><xsl:value-of select="price"/></price>
  </xsl:template>
</xsl:stylesheet>

In this example, the xsl:if element checks if the price of a book is less than 50. If the condition is true for at least one book, the <cheap-book> element is added to the output, and the corresponding <book> elements with prices less than 50 are processed within the <cheap-book> element.

Using xsl:if, you can control the application of templates or the processing of nodes in your XSLT transformation based on specific conditions. It provides a flexible way to handle different scenarios and tailor the output according to the input data.