Assume I have variables $a
, $b
, $c
and $d
which all hold numbers. I would like to get the smallest (largest) value. My typical XSLT 1.0 approach to this is
<xsl:variable name="minimum">
<xsl:for-each select="$a | $b | $c | $d">
<xsl:sort
select="."
data-type="number"
order="ascending" />
<xsl:if test="position()=1"><xsl:value-of select="." /></xsl:if>
</xsl:for-each>
</xsl:variable>
However, my xslt 1.0 processor complains with
runtime error: file stylesheet.xslt line 106 element for-each
The 'select' expression does not evaluate to a node set.
How can I compute the minimum (maximum) of the given values?
Of course, I could use a long series of <xsl:when>
statements and check all combinations, but I'd rather like a smaller solution.
If the variables have statically defined values (not dynamically computed), then something like the following can be done with XSLT 1.0:
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text"/>
<xsl:variable name="vA" select="3"/>
<xsl:variable name="vB" select="1"/>
<xsl:variable name="vC" select="9"/>
<xsl:variable name="vD" select="5"/>
<xsl:template match="/">
<xsl:for-each select=
"document('')/*/xsl:variable
[contains('|vA|vB|vC|vD|', concat('|', @name, '|'))]
/@select
">
<xsl:sort data-type="number" order="ascending"/>
<xsl:if test="position() = 1">
Smallest: <xsl:value-of select="."/>
</xsl:if>
<xsl:if test="position() = last()">
Largest: <xsl:value-of select="."/>
</xsl:if>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>
When this transformation is applied on any XML document (not used), the wanted, correct result is produced:
Smallest: 1
Largest: 9
II. Now, suppose the variables are dynamically defined.
We can do something like this (but need the xxx:node-set()
extension function):
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:ext="http://exslt.org/common">
<xsl:output method="text"/>
<xsl:variable name="vA" select="number(/*/*[3])"/>
<xsl:variable name="vB" select="number(/*/*[1])"/>
<xsl:variable name="vC" select="number(/*/*[9])"/>
<xsl:variable name="vD" select="number(/*/*[5])"/>
<xsl:template match="/">
<xsl:variable name="vrtfStore">
<num><xsl:value-of select="$vA"/></num>
<num><xsl:value-of select="$vB"/></num>
<num><xsl:value-of select="$vC"/></num>
<num><xsl:value-of select="$vD"/></num>
</xsl:variable>
<xsl:for-each select="ext:node-set($vrtfStore)/*">
<xsl:sort data-type="number" order="ascending"/>
<xsl:if test="position() = 1">
Smallest: <xsl:value-of select="."/>
</xsl:if>
<xsl:if test="position() = last()">
Largest: <xsl:value-of select="."/>
</xsl:if>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>
when this transformation is applied on the following XML document:
<nums>
<num>01</num>
<num>02</num>
<num>03</num>
<num>04</num>
<num>05</num>
<num>06</num>
<num>07</num>
<num>08</num>
<num>09</num>
<num>10</num>
</nums>
the wanted, correct result is produced:
Smallest: 1
Largest: 9
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