XSLT <xsl:when>
XSLT <xsl:when>
The <xsl:when>
element is used to specify an action for the <xsl:choose>
element. The <xsl:when>
element evaluates an expression, and if it returns true, an action is performed.
note
The <xsl:when>
element is used in conjunction with <xsl:choose>
and <xsl:otherwise>
to express multiple conditional tests.
Syntax
<xsl:when test="boolean-expression">
<!-- Content: template -->
</xsl:when>
Attributes
Attribute | Value | Required/Optional | Description |
---|---|---|---|
test | boolean-expression | Required | Specifies a Boolean expression to be tested |
Example
Let's see some examples:
Example 1
The code below will add a red background-color to the author column when the price of the book is higher than 15.
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<html>
<body>
<h2>The bookstore</h2>
<table border="1">
<tr bgcolor="#9acd32">
<th>Title</th>
<th>Author</th>
</tr>
<xsl:for-each select="bookstore/book">
<tr>
<td><xsl:value-of select="title"/></td>
<xsl:choose>
<xsl:when test="price>'15'">
<td bgcolor="#ff0000">
<xsl:value-of select="author"/></td>
</xsl:when>
<xsl:otherwise>
<td><xsl:value-of select="author"/></td>
</xsl:otherwise>
</xsl:choose>
</tr>
</xsl:for-each>
</table>
</body>
</html>
</xsl:template>
</xsl:stylesheet>
Example 2
Declare a variable named "color". Set its value to the color attribute of the current element. If the current element has no color attribute, the value of "color" will be "red":
<xsl:variable name="color">
<xsl:choose>
<xsl:when test="@color">
<xsl:value-of select="@color"/>
</xsl:when>
<xsl:otherwise>red</xsl:otherwise>
</xsl:choose>
</xsl:variable>