xsl:if
Used for conditional processing. It takes a mandatory test
attribute, whose value is a boolean expression. The contents of the
xsl:if element are expanded only of the expression is true.
Category: instruction
Content:
sequence-constructor
Permitted parent elements:
any XSLT element whose content model is
sequence-constructor; any literal result element
Attributes
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The boolean expression to be tested. The full syntax of boolean expressions is outlined in XPath Syntax. |
Notes on the Saxon implementation
Provided that syntax extensions are enabled, Saxon (from 10) allows the xsl:if instruction
to have a then and/or else attribute. The then attribute
defines an expression to be evaluated when the test condition is true; if it is
present, then the xsl:if instruction must be empty. The else attribute
defines an expression to be evaluated when the test condition is false; it
defaults to the empty sequence.
Examples
Example 1
To include a hyperlink in the output only if the current element has a
preface attribute:
Example 2
A function that performs head-tail recursion, using Saxon's extended syntax:
<xsl:function name="f:product" as="xs:double"> <xsl:param name="input" as="xs:double*"/> <xsl:if test="empty($input)" then="1" else="head($input) * f:product(tail($input))"/> </xsl:function>