Converting CSV Files to Hierarchical XML Using One XSL Transformation

Question

I am attempting to convert a comma delimited list into an XML file with a hierarchical structure. To do this, I am using XSLT alone, preferably with one transform. There is a previous example that is similar, but it does not go into the depth of creating subelements, which I see is a common problem during this kind of transformation that to my knowledge has been left without a clear answer.

Similar Example: XSLT 2.0 to convert CSV to XML format

CSV Example:

ClaimRef,HandlerRef,ClaimType,Date,Area,SettleDate,ClaimStatus,ClaimantName
1,1/1,Liability,08-12-2013,US,23-05-2014,Closed,Mark
2,1/2,Liability,08-10-2013,UK,23-02-2014,Closed,John

Desired XML Output Format (Where this is different because it contains subelements):

<Claims>
 <Claim>
  <ClaimRef></ClaimRef>
  <HandlerRef></HandlerRef>
  <ClaimType></ClaimType>
  <Date></Date>
  <Area></Area>
  <SettleDate></SettleDate>
  <ImportantDevision>
      <ClaimStatus></ClaimStatus>
      <ClaimantName></ClaimantName>
  </ImportantDivision>
 </Claim>
</Claims>

Working XSLT Version 2.0 Without Subelements:

<xsl:param name="inputCsv"/>
<xsl:template match="/" name="csv2xml">
    <Claims>
         <xsl:variable name="csv" select="unparsed-text($csv-uri, $csv-encoding)"/>
                <!--Get Header-->
                <xsl:variable name="header-tokens" as="xs:string*">
                    <xsl:analyze-string select="$csv" regex="\r\n?|\n">
                        <xsl:non-matching-substring>
                            <xsl:if test="position()=1">
                                <xsl:copy-of select="tokenize(.,',')"/>                                        
                            </xsl:if>
                        </xsl:non-matching-substring>
                    </xsl:analyze-string>
                </xsl:variable>                    
                <xsl:analyze-string select="$csv" regex="\r\n?|\n">
                    <xsl:non-matching-substring>
                        <xsl:if test="not(position()=1)">
                            <Claim>
                                <xsl:for-each select="tokenize(.,',')">
                                    <xsl:variable name="pos" select="position()"/>
                                    <xsl:element name="{$header-tokens[$pos]}">
                                        <xsl:value-of select="."/>
                                    </xsl:element>
                                </xsl:for-each>
                            </Claim>
                        </xsl:if>
                    </xsl:non-matching-substring>
                </xsl:analyze-string>
    </Claims>
</xsl:template>

I would then have a dummy XML file with in order trick the XSL to transform my CSV file. Perhaps a better question would be how to distinguish divisions from one another using only XSLT before Tag Names, attributes, ids, etc. are created?

Answer 1

You haven't really explained what are the criteria to nest elements, but as already pointed out in a comment you can transform the flat XML you create first in any way. The following assumes you simply want to nest adjacent elements starting with the name Claim:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:xs="http://www.w3.org/2001/XMLSchema" exclude-result-prefixes="xs" version="2.0">

    <xsl:param name="csv-uri" as="xs:string" select="'test2017062301.txt'"/>
    <xsl:param name="csv-encoding" as="xs:string" select="'Windows-1252'"/>

    <xsl:output indent="yes"/>

    <xsl:template match="@* | node()">
        <xsl:copy>
            <xsl:apply-templates select="@* | node()"/>
        </xsl:copy>
    </xsl:template>

    <xsl:template match="/" name="csv2xml">
        <Claims>
            <xsl:variable name="csv" select="unparsed-text($csv-uri, $csv-encoding)"/>
            <xsl:variable name="flat-xml">
                <!--Get Header-->
                <xsl:variable name="header-tokens" as="xs:string*">
                    <xsl:analyze-string select="$csv" regex="\r\n?|\n">
                        <xsl:non-matching-substring>
                            <xsl:if test="position() = 1">
                                <xsl:copy-of select="tokenize(., ',')"/>
                            </xsl:if>
                        </xsl:non-matching-substring>
                    </xsl:analyze-string>
                </xsl:variable>
                <xsl:analyze-string select="$csv" regex="\r\n?|\n">
                    <xsl:non-matching-substring>
                        <xsl:if test="not(position() = 1)">
                            <Claim>
                                <xsl:for-each select="tokenize(., ',')">
                                    <xsl:variable name="pos" select="position()"/>
                                    <xsl:element name="{$header-tokens[$pos]}">
                                        <xsl:value-of select="."/>
                                    </xsl:element>
                                </xsl:for-each>
                            </Claim>
                        </xsl:if>
                    </xsl:non-matching-substring>
                </xsl:analyze-string>
            </xsl:variable>
            <xsl:apply-templates select="$flat-xml/*"/>
        </Claims>
    </xsl:template>

    <xsl:template match="Claim">
        <xsl:copy>
            <xsl:for-each-group select="*" group-adjacent="starts-with(local-name(), 'Claim')">
                <xsl:choose>
                    <xsl:when test="current-grouping-key() and current-group()[2]">
                        <ClaimDivision>
                            <xsl:copy-of select="current-group()"/>
                        </ClaimDivision>
                    </xsl:when>
                    <xsl:otherwise>
                        <xsl:copy-of select="current-group()"/>
                    </xsl:otherwise>
                </xsl:choose>
            </xsl:for-each-group>
        </xsl:copy>
    </xsl:template>

</xsl:stylesheet>

Result for your sample input then is

<?xml version="1.0" encoding="UTF-8"?>
<Claims>
   <Claim>
      <ClaimRef>1</ClaimRef>
      <HandlerRef>1/1</HandlerRef>
      <ClaimType>Liability</ClaimType>
      <Date>08-12-2013</Date>
      <Area>US</Area>
      <SettleDate>23-05-2014</SettleDate>
      <ClaimDivision>
         <ClaimStatus>Closed</ClaimStatus>
         <ClaimantName>Mark</ClaimantName>
      </ClaimDivision>
   </Claim>
   <Claim>
      <ClaimRef>2</ClaimRef>
      <HandlerRef>1/2</HandlerRef>
      <ClaimType>Liability</ClaimType>
      <Date>08-10-2013</Date>
      <Area>UK</Area>
      <SettleDate>23-02-2014</SettleDate>
      <ClaimDivision>
         <ClaimStatus>Closed</ClaimStatus>
         <ClaimantName>John</ClaimantName>
      </ClaimDivision>
   </Claim>
</Claims>