Nic Miloslav     Example 23    KEYWORDS      EXAMPLES      AUTHORS     

Boolean function is very useful, if you want to check, if a variable has some defined value. Compare Stylesheet 1 and Stylesheet 2


     XML     HOME     XSL 1     XSL 2      
<xslTutorial >
<animal>cat</animal>
<animal>dog</animal>
<animal>cow</animal>
</xslTutorial>

     XSL 1     HOME     XML     HTML 1     OUTPUT 1     
<xsl:stylesheet version='1.0' xmlns:xsl='http://www.w3.org/1999/XSL/Transform' >
<xsl:variable name="color">red</xsl:variable>
<xsl:template match="//animal">
<xsl:choose>
<xsl:when test='boolean($color)'>
<P style="color:{$color}">
<xsl:value-of select="."/></P>
</xsl:when>
<xsl:otherwise>
<P><xsl:value-of select="."/></P>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>

     HTML 1     HOME     XML     XSL 1     OUTPUT 1     
<HTML>
<HEAD> </HEAD>
<BODY>
<P style="color:red">cat</P>
<P style="color:red">dog</P>
<P style="color:red">cow</P> </BODY> </HTML>

     OUTPUT 1     HOME     XML     XSL 1     HTML 1     

cat

dog

cow


     XSL 2     HOME     XML     HTML 2     OUTPUT 2     
<xsl:stylesheet version='1.0' xmlns:xsl='http://www.w3.org/1999/XSL/Transform' >
<xsl:variable name="color"></xsl:variable>
<xsl:template match="//animal">
<xsl:choose>
<xsl:when test='boolean($color)'>
<P style="color:{$color}">
<xsl:value-of select="."/></P>
</xsl:when>
<xsl:otherwise>
<P><xsl:value-of select="."/></P>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>

     HTML 2     HOME     XML     XSL 2     OUTPUT 2     
<HTML>
<HEAD> </HEAD>
<BODY>
<P>cat</P>
<P>dog</P>
<P>cow</P> </BODY> </HTML>

     OUTPUT 2     HOME     XML     XSL 2     HTML 2     

cat

dog

cow