XSLT

Branching Elements of XSLT

Three XSLT elements are used for branching: <xsl:if>, <xsl:choose>, and <xsl:for-each>. The first two are much like the if and case statements you may be familiar with from other languages, while the for-each element is significantly different from the for or do-while structures in other languages. We’ll discuss all of them here.

The <xsl:if> Element

The <xsl:if> element looks like this:

<xsl:if test="count(zone) &gt; 2">
  <xsl:text>Applicable zones: </xsl:text>
  <xsl:apply-templates select="zone"/>
</xsl:if>

The <xsl:if> element, surprisingly enough, implements an if statement. The element has only one attribute, test. If the value of test evaluates to the boolean value true, then all elements inside the <xsl:if> are processed. If test evaluates to false, then the contents of the <xsl:if> element are ignored. (If you want to implement an if-then-else statement, check out the <xsl:choose> element described in the next section.)

Notice that we used > instead of > in the attribute value. You’re always safe using > here, although some XSLT processors process the greater-than sign correctly if you use > instead. If you need to use the less-than operator (<), you’ll have to use the < entity. The same holds true for the less-than-or-equal operator (<=) and the greater-than-or-equal (>=) operators. See Section B.4.2 for more information on this topic.

Converting to boolean values

The <xsl:if> element is pretty simple, but it’s the first time ...