Apply XSLT Transform to an already transformed XML - xslt

Question

All,
I have an XML file which I transform it using an XSLT document to another XML.
Can I define another set of transformations in the same XSLT file to be applied in the result XML of the first transformation?
Thanks,
MK

Answer 1

Yes.
I. This XSLT 1.0 transformation:
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:ext="http://exslt.org/common"
xmlns:msxsl="urn:schemas-microsoft-com:xslt"
>
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:variable name="vrtfPass1">
<xsl:apply-templates/>
</xsl:variable>
<xsl:template match="node()|#*" name="identity">
<xsl:copy>
<xsl:apply-templates select="node()|#*"/>
</xsl:copy>
</xsl:template>
<xsl:template match="node()|#*" mode="pass2">
<xsl:copy>
<xsl:apply-templates select="node()|#*" mode="pass2"/>
</xsl:copy>
</xsl:template>
<xsl:template match="num/text()">
<xsl:value-of select="2*."/>
</xsl:template>
<xsl:template match="num/text()" mode="pass2">
<xsl:value-of select="1+."/>
</xsl:template>
<xsl:template match="/">
<xsl:apply-templates select="ext:node-set($vrtfPass1)/*" mode="pass2"/>
</xsl:template>
</xsl:stylesheet>
when applied on this XML document:
<t>
<num>1</num>
<num>2</num>
<num>3</num>
<num>4</num>
<num>5</num>
</t>
produces:
<t>
<num>3</num>
<num>5</num>
<num>7</num>
<num>9</num>
<num>11</num>
</t>
Do note:
Two transformations are actually performed, the second is performed on the result of the first.
The result of the first transformation is the content of the variable $vrtfPass1.
In XSLT 1.0 the type of variables that contain dynamically generated (temporary) XML trees (XML document or XML fragment) is RTF (Result-Tree-Fragment). No XPath operations are possible on an RTF -- it needs to be converted to a regular node-set using the extension function xxx:node-set(), which is provided by the vast majority of XSLT 1.0 processor vendors. In this example exslt:node-set() is used, because EXSLT is implemented by many different vendors.
The second transformation is applied on the result of the first: <xsl:apply-templates select="ext:node-set($vrtfPass1)/*" mode="pass2"/> . A separate mode is used in order to cleanly separate the code of the two transformations.
The first transformation multiplies each num/text() by 2. The second transformation increments each num/text(). The result is 2*.+1
II. This XSLT 2.0 transformation:
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema" >
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:variable name="vPass1">
<xsl:apply-templates mode="pass1"/>
</xsl:variable>
<xsl:template match="node()|#*" mode="pass1">
<xsl:copy>
<xsl:apply-templates select="node()|#*" mode="pass1"/>
</xsl:copy>
</xsl:template>
<xsl:template match="node()|#*" mode="pass2">
<xsl:copy>
<xsl:apply-templates select="node()|#*" mode="pass2"/>
</xsl:copy>
</xsl:template>
<xsl:template match="num/text()" mode="pass1">
<xsl:value-of select="2*xs:integer(.)"/>
</xsl:template>
<xsl:template match="num/text()" mode="pass2">
<xsl:value-of select="1+."/>
</xsl:template>
<xsl:template match="/">
<xsl:apply-templates select="$vPass1" mode="pass2"/>
</xsl:template>
</xsl:stylesheet>
when applied on the same XML document, produces the same wanted and correct result.
Do note: In XSLT 2.0/XPath 2.0 the RTF type has been abolished. No xxx:node-set() extension function is needed.