Transform XML to XML using an XSLT file

Question

I'm trying to transform XML from one format to another but haven't had much luck in finding resources that explain how this works too well. How can I set data inside the XML tags using a value that is inside other XML tags?

Here is the starting XML

<?xml version="1.0" encoding="utf-8"?>
<In xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="in.xsd">
  <Submit ID="1234">
    <Label>
      <Code>300</Code>
      <Source>27</Source>
    </Label>
    <Data>
      <Number>18</Number>
      <Date>2018-04-01</Date>
      <IsFile>0</IsFile>
      <Location></Location>
      <Files>
        <File>
          <Name>red.pdf</Name>
          <Classification>FILE</Classification>
        </File>
        <File>
          <Name>picture.pdf</Name>
          <Type>IMAGE</Type>
        </File>
      </Files>
    </Data>
  </Submit>
</In>

My current XSLT

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:msxsl="urn:schemas-microsoft-com:xslt" exclude-result-prefixes="msxsl">
    <xsl:output method="xml" indent="yes"/>

  <xsl:template match="/">
    <xsl:apply-templates select="In"/>
  </xsl:template>
  <xsl:template match="In">
    <Q xmlns:tns="Q" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" Source="{@source}" Notification="true">
      <xsl:value-of select="Submit/Label/Source"/>
    </Q>
  </xsl:template>
</xsl:stylesheet>

Expected end result after using XSLT to transform the XML file.

<?xml version="1.0" encoding="utf-8"?>
<Q xmlns:tns="Q" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="scheme.xsd" Source="27" Notification="true">
<SubmitID="1234">
<Label>
    <Code>300</Code>
    <Source>27</Source>
</Label>
<Data>
    <Number>18</Number>
    <Date>2018-04-01</Date>
    <IsFile>0</IsFile>
</Data>
<Files>
    <File>
        <Name>red.pdf</Name>
        <Type>FILE</Type>
    </File>
    <File>
        <Name>picture.pdf</Name>
        <Type>IMAGE</Type>
    </File>
</Files>
</Submit>
</Q>

The XSLT is incomplete and doesn't produce the expected outcome. I am still missing code to generate what goes in between.

Answer 1

Try the following XSLT-1.0 stylesheet:

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:msxsl="urn:schemas-microsoft-com:xslt" exclude-result-prefixes="msxsl">
  <xsl:output method="xml" indent="yes"/>

  <!-- identity template - copies all elements and its children and attributes -->    
  <xsl:template match="node()|@*">
      <xsl:copy>
        <xsl:apply-templates select="node()|@*" />
      </xsl:copy>
  </xsl:template>    

  <xsl:template match="/In">                   <!-- Remove the 'In' element -->
    <xsl:apply-templates select="node()"/>
  </xsl:template>

  <xsl:template match="Submit">                <!-- Create the 'Q' element and its sub-elements -->
    <Q xmlns:tns="Q" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" Source="{@source}" Notification="true">
        <xsl:copy>
            <xsl:copy-of select="@*"/>
            <xsl:apply-templates select="Label" />
            <xsl:apply-templates select="Data" />
            <xsl:apply-templates select="Data/Files" />
        </xsl:copy>
    </Q>
  </xsl:template>

  <xsl:template match="Data">                  <!-- Create the 'Data' sub-element without all of its children -->
    <xsl:copy>
        <xsl:copy-of select="Number"/>
        <xsl:copy-of select="Date"/>
        <xsl:copy-of select="IsFile"/>
    </xsl:copy>
  </xsl:template>  

</xsl:stylesheet>

Answer 2

This is returning most of what I require. Is this the correct way to do this?

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:msxsl="urn:schemas-microsoft-com:xslt" exclude-result-prefixes="msxsl">
    <xsl:output method="xml" indent="yes"/>

  <xsl:template match="/">
    <xsl:apply-templates select="In"/>
  </xsl:template>

  <xsl:template match="In">
    <Q xmlns:tns="Q" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" Source="{Submit/Label/Source}" Notification="true">
      <xsl:value-of select="Submit/Label/Source"/>
      <Label>
      <Code><xsl:value-of select="Submit/Label/Code"/></Code>
      <Source><xsl:value-of select="Submit/Label/Source"/></Source>
      </Label>
    </Q>
  </xsl:template>
</xsl:stylesheet>