Import Transformation Patterns (XSLT)

Import Transformation Patterns (XSLT)

This article provides practical, ready-to-use XSLT 1.0 code for the most common data manipulation tasks. Each pattern is presented in a separate section. Within each section, you'll find tabs explaining the Goal, showing the Source XML you're starting with, the XSLT Stylesheet needed to transform it, and the final Resulting Target XML.

You can use these patterns as a starting point and adapt them to your specific needs in the Transformation Editor.

For a refresher on general XSLT syntax and functions, please refer to our core Clevr XSLT Documentation.
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Pattern 1: Basic CSV to Target XML
This is the most fundamental pattern. It shows how to convert the standard source XML generated from a CSV file into the required target format.

Goal

Convert a simple CSV structure to the <importedData> format, which is required by the importer.

Source XML (from a CSV)

  1. <root>
  2.   <row>
  3.     <StudentID>101</StudentID>
  4.     <FirstName>Jane</FirstName>
  5.     <LastName>Doe</LastName>
  6.   </row>
  7.   <row>
  8.     <StudentID>102</StudentID>
  9.     <FirstName>John</FirstName>
  10.     <LastName>Smith</LastName>
  11.   </row>
  12. </root>

XSLT Stylesheet

  1. <?xml version="1.0"?>
  2. <xsl:transform version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
  3.     xmlns:date="urn:date" xmlns:math="urn:math" xmlns:str="urn:str" exclude-result-prefixes="date math str">

  5.   <xsl:template match="Root">
  6.     <importedData>
  7.       <xsl:for-each select="row">
  8.         <row>
  9.           <column header="ID">
  10.             <xsl:value-of select="StudentID"/>
  11.           </column>
  12.           <column header="FName">
  13.             <xsl:value-of select="FirstName"/>
  14.           </column>
  15.           <column header="LName">
  16.             <xsl:value-of select="LastName"/>
  17.           </column>
  18.         </row>
  19.       </xsl:for-each>
  20.     </importedData>
  21.   </xsl:template>

  23. </xsl:transform>

How the Code Works

  1. <xsl:template match="/root">: This line starts a template that matches the <root> element of your source XML.
  2. <importedData>: This creates the main wrapper element required for the target format.
  3. <xsl:for-each select="row">: This is a loop. It finds every <row> element inside <root> and repeats the code within it for each one.
  4. <column header="...">: Inside the loop, this creates the required <column> element for each piece of data.
  5. <xsl:value-of select="StudentID"/>: This finds the value of the <StudentID> element from the source XML and places it inside the <column> tag.

Resulting Target XML

  1. <importedData>
  2.   <row>
  3.     <column header="ID">101</column>
  4.     <column header="FName">Jane</column>
  5.     <column header="LName">Doe</column>
  6.   </row>
  7.   <row>
  8.     <column header="ID">102</column>
  9.     <column header="FName">John</column>
  10.     <column header="LName">Smith</column>
  11.   </row>
  12. </importedData>
Pattern 2: Combining Two Fields into One
This pattern shows how to concatenate values from two source nodes (FirstName and LastName) into a single FullName column.

Goal

Combine a first and last name into a single "FullName" field.

Source XML (from a CSV)

  1. <root>
  2.   <row>
  3.     <FirstName>Jane</FirstName>
  4.     <LastName>Doe</LastName>
  5.   </row>
  6. </root>

XSLT Stylesheet

This snippet would be placed inside the <row> element of your main template (as shown in Pattern 1).
  1. <column header="FullName">
  2.   <xsl:value-of select="concat(FirstName, ' ', LastName)"/>
  3. </column>

How the Code Works

  1. <xsl:value-of select="..."/>: This tells the system to output the result of an expression.
  2. concat(FirstName, ' ', LastName): This is the core function. It takes the value of the <FirstName> node, adds a literal space ' ', and then adds the value of the <LastName> node, joining them together into a single string.

Resulting Target XML

  1. <importedData>
  2.   <row>
  3.     <column header="FullName">Jane Doe</column>
  4.   </row>
  5. </importedData>
Pattern 3: Using Conditional Logic (If/Then)
This pattern shows how to set the value of a column based on a condition.

Goal

Create a column named Status. If the source IsActive node is "true", set the value to "Active". Otherwise, set it to "Inactive".

Source XML (from a JSON file)

  1. <root>
  2.   <element>
  3.     <StudentID>101</StudentID>
  4.     <IsActive>true</IsActive>
  5.   </element>
  6.   <element>
  7.     <StudentID>102</StudentID>
  8.     <IsActive>false</IsActive>
  9.   </element>
  10. </root>

XSLT Stylesheet

This snippet goes inside a <row> element.
  1. <column header="Status">
  2.   <xsl:choose>
  3.     <xsl:when test="IsActive = 'true'">
  4.       <xsl:value-of select="'Active'"/>
  5.     </xsl:when>
  6.     <xsl:otherwise>
  7.       <xsl:value-of select="'Inactive'"/>
  8.     </xsl:otherwise>
  9.   </xsl:choose>
  10. </column>

How the Code Works

  1. <xsl:choose>: This element starts a block of conditional choices, similar to an if/else statement.
  2. <xsl:when test="IsActive = 'true'">: This is the if condition. The test attribute checks if the value of the <IsActive> node is equal to the string 'true'.
  3. <xsl:value-of select="'Active'"/>: If the test passes, this line outputs the literal string 'Active'.
  4. <xsl:otherwise>: This is the else block. It catches any case where the <xsl:when> test fails.
  5. <xsl:value-of select="'Inactive'"/>: This line outputs the literal string 'Inactive' if the condition is not met.

Resulting Target XML

  1. <importedData>
  2.   <row>
  3.     <column header="Status">Active</column>
  4.   </row>
  5.   <row>
  6.     <column header="Status">Inactive</column>
  7.   </row>
  8. </importedData>
Pattern 4: Creating Repeater Data
This pattern shows how to process a nested structure to create the <instance> nodes required for a repeater.

Goal 

Convert a nested list of contacts from a JSON file into repeater instances.

Source XML (from a JSON file)

  1. <root>
  2.   <element>
  3.     <StudentID>4876</StudentID>
  4.     <EmergencyContacts>
  5.       <ContactName>Maria Garcia</ContactName>
  6.       <ContactPhone>555-0101</ContactPhone>
  7.     </EmergencyContacts>
  8.     <EmergencyContacts>
  9.       <ContactName>Luis Garcia</ContactName>
  10.       <ContactPhone>555-0102</ContactPhone>
  11.     </EmergencyContacts>
  12.   </element>
  13. </root>

XSLT Stylesheet

This snippet goes inside a <row> element.
  1. <column header="ContactNameRepeater">
  2.   <xsl:for-each select="EmergencyContacts">
  3.     <instance>
  4.       <xsl:value-of select="ContactName"/>
  5.     </instance>
  6.   </xsl:for-each>
  7. </column>
  8. <column header="ContactPhoneRepeater">
  9.   <xsl:for-each select="EmergencyContacts">
  10.     <instance>
  11.       <xsl:value-of select="ContactPhone"/>
  12.     </instance>
  13.   </xsl:for-each>
  14. </column>

How the Code Works

  1. This pattern uses two separate <column> elements, one for each field in the repeater.
  2. <xsl:for-each select="EmergencyContacts">: This starts a nested loop. For the current record, it finds every <EmergencyContacts> element and repeats the code inside for each one.
  3. <instance>: Inside the loop, this creates the required <instance> tag for each contact.
  4. <xsl:value-of select="ContactName"/>: This pulls the ContactName from the current <EmergencyContacts> element being processed in the loop. The process is repeated for the ContactPhone.

Resulting Target XML

  1. <importedData>
  2.   <row>
  3.     <column header="ContactNameRepeater">
  4.       <instance>Maria Garcia</instance>
  5.       <instance>Luis Garcia</instance>
  6.     </column>
  7.     <column header="ContactPhoneRepeater">
  8.       <instance>555-0101</instance>
  9.       <instance>555-0102</instance>
  10.     </column>
  11.   </row>
  12. </importedData>
 
 

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