XSLT, Renaming Elements using mapping table based on Attribute's value

Question

How to rename the elements according to a mapping table based on attribute's of the element?

Any suggestions would be much appreciated. Maybe a XSLT 2.0 template and modifying the mapping table for better solution?

Many thanks in advance Thomas

Original XML:

<transaction>
  <records type="1" >
      <record type="1" >
        <field number="1" >
            <item>223</item>
        </field>
        <field number="2" >
            <item>456</item>
        </field>
      </record>
  </records>

  <records type="14" >
      <record type="14" >
        <field number="1" >
            <item>777</item>
        </field>
        <field number="2" >
            <item>678</item>
        </field>
      </record>

      <record type="14" >
        <field number="1" >
            <item>555</item>
        </field>
      </record>
  </records>
</transaction>

Mapping table:

<xsl:stylesheet>
  <mapping type="1" from="record" to="first-record">
      <map number="1" from="field" to="great-field"/>
      <map number="2" from="field" to="good-field"/>
  </mapping>

  <mapping type="14" from="record" to="real-record">
      <map number="1" from="field" to="my-field"/>
      <map number="2" from="field" to="other-field"/>
  </mapping>     
</xsl:stylesheet>

Result after the transformation:

<transaction>
  <records type="1" >
      <first-record type="1" >
        <great-field number="1" >
            <item >223</item>
        </great-field>
        <good-field number="2" >
            <item >456</item>
        </good-field>
      </first-record>
  </records>

  <records type="14" >
      <real-record type="14" >
        <my-field number="1" >
            <item >777</item>
        </my-field>
        <other-field number="2" >
            <item >678</item>
        </other-field>
      </real-record>

      <real-record type="14" >
        <my-field number="1" >
            <item >555</item>
        </my-field>
      </real-record>
  </records>
</transaction>

Answer 1

Here is an XSLT 3.0 stylesheet (executable with Saxon 9.8 any edition or Altova XMLSpy/Raptor 2017 or 2018) that transforms the mapping into an XSLT 3.0 stylesheet and then executes it with the transform function from XPath 3.1:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns:math="http://www.w3.org/2005/xpath-functions/math"
    xmlns:axsl="http://www.w3.org/1999/XSL/Transform-alias"
    exclude-result-prefixes="xs math axsl"
    version="3.0">

    <xsl:param name="mapping">
        <mapping type="1" from="record" to="first-record">
            <map number="1" from="field" to="great-field"/>
            <map number="2" from="field" to="good-field"/>
        </mapping>

        <mapping type="14" from="record" to="real-record">
            <map number="1" from="field" to="my-field"/>
            <map number="2" from="field" to="other-field"/>
        </mapping>  
    </xsl:param>

    <xsl:namespace-alias stylesheet-prefix="axsl" result-prefix="xsl"/>

    <xsl:variable name="stylesheet">
        <axsl:stylesheet version="3.0">
            <axsl:mode name="transform" on-no-match="shallow-copy"/>
            <xsl:apply-templates select="$mapping/mapping" mode="xslt-modes"/>
            <xsl:apply-templates select="$mapping/mapping" mode="xslt-code"/>
        </axsl:stylesheet>
    </xsl:variable>

    <xsl:template match="mapping" mode="xslt-modes">
        <axsl:mode name="transform-{position()}" on-no-match="shallow-copy"/>
    </xsl:template>

    <xsl:template match="mapping" mode="xslt-code">
        <axsl:template match="{@from}[@type = '{@type}']" mode="transform">
            <axsl:element name="{@to}">
                <axsl:apply-templates select="@* | node()" mode="transform-{position()}"/>
            </axsl:element>
        </axsl:template>
        <xsl:apply-templates mode="xslt-code">
            <xsl:with-param name="pos" select="position()"/>
        </xsl:apply-templates>
    </xsl:template>

    <xsl:template match="map" mode="xslt-code">
        <xsl:param name="pos"/>
        <axsl:template match="{@from}[@number = '{@number}']" mode="transform-{$pos}">
            <axsl:element name="{@to}">
                <axsl:apply-templates select="@* | node()" mode="#current"/>
            </axsl:element>
        </axsl:template>
    </xsl:template> 

    <xsl:template match="/">
        <xsl:message select="$stylesheet"></xsl:message>
        <xsl:sequence select="transform(map { 'source-node' : ., 'stylesheet-node' : $stylesheet , 'initial-mode' : xs:QName('transform') })?output"/>
    </xsl:template>

</xsl:stylesheet>

Remove or comment out the <xsl:message select="$stylesheet"></xsl:message> which is only in there to show the produced stylesheet code.

Of course the approach to transform the mapping into an XSLT stylesheet can also be used with XSLT 2.0 but then you need to run the created stylesheet from outside XSLT with e.g. Java or C# or by hand in your editor.