XSLT Viewer¶

Last Updated: May 2026 | Version: 1.10.0

Note (Phase 10c): The standalone XSLT Viewer tab has been retired. Quick XSLT transformations now live in the Unified Shell's Transform panel (set a stylesheet, transform, preview the result, open in browser), and full editing/parameters/batch processing remain in the XSLT Developer. The workflow below is unchanged in spirit; the controls are now part of the Transform side panel rather than a dedicated tab.

The XSLT Viewer allows you to quickly transform XML documents using XSLT stylesheets. Simply select your files and view the results immediately.

Overview¶

The XSLT Viewer is designed for quick transformations where you want to see results immediately. In the Unified Shell these quick transformations live in the Transform panel (open it from the Transform icon in the activity bar). For advanced features like live editing, parameters, and batch processing, use the XSLT Developer.

Transform panel in the Unified Shell Quick XSLT/XQuery transformations now live in the Unified Shell's Transform panel

What is XSLT?¶

XSLT (Extensible Stylesheet Language Transformations) is a language for transforming XML documents. Think of it like a recipe that tells the computer how to convert your XML data into a different format such as HTML, text, or another XML structure.

XSLT Concept XSLT transformation: XML input + XSLT rules = Output

Common uses:

Convert XML data to HTML for web display
Transform XML between different schemas
Generate reports from XML data
Extract and restructure data

How to Use¶

Step 1: Select Your Files¶

Open your XML source file in the editor host so it is the active document - the panel's INPUT section follows the active tab by default (use Change → Select XML file… to transform a fixed file from disk instead)
In the STYLESHEET section, click Change to choose an XSLT stylesheet (the clock icon offers your recently used stylesheets)

Step 2: Run and View the Results¶

Click Run Transform. The result appears in the OUTPUT panel that docks below the editor - the source stays on top, the result shows underneath. The panel header shows a format badge, a success/error status with timing (Transformed · N ms · M chars), and view toggles:

View	Description
Text	The raw result as text (the default)
Preview	For HTML/XHTML output: the result rendered as a web page
Table	For XQuery results that return a sequence: the items shown as a table

The OUTPUT METHOD defaults to Auto: the format (XML, HTML, XHTML, Text, JSON) is detected from the stylesheet's xsl:output declaration. Pick a concrete segment to override the detection.

Transform Panel Actions¶

Control	Description
Run Transform	Runs the transformation with the current stylesheet and input
Open result as editor tab	(OUTPUT panel) Opens the result as an editable, savable document
Open in browser	(OUTPUT panel) Opens the result in your default web browser
Save result…	(OUTPUT panel) Writes the result straight to a file
⋮ → Watch stylesheet file	Re-runs automatically when the stylesheet changes on disk
⋮ → Live preview	Re-runs automatically (debounced) while you edit the input document
⋮ → Auto-open result tab	Also opens every successful result as an editor tab (off by default)

XSLT Examples¶

FreeXmlToolkit includes example XSLT stylesheets in the examples/ folder. Here are some common XSLT patterns:

Example 1: Basic XML to HTML¶

Transform a simple XML list to an HTML table:

<!-- Input XML -->
<books>
    <book>
        <title>XML for Beginners</title>
        <author>Jane Smith</author>
        <price>29.99</price>
    </book>
    <book>
        <title>Advanced XSLT</title>
        <author>John Doe</author>
        <price>49.99</price>
    </book>
</books>

<!-- XSLT Stylesheet -->
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:output method="html" indent="yes"/>

  <xsl:template match="/">
    <html>
      <head><title>Book List</title></head>
      <body>
        <h1>Available Books</h1>
        <table border="1">
          <tr>
            <th>Title</th>
            <th>Author</th>
            <th>Price</th>
          </tr>
          <xsl:for-each select="books/book">
            <tr>
              <td><xsl:value-of select="title"/></td>
              <td><xsl:value-of select="author"/></td>
              <td><xsl:value-of select="price"/></td>
            </tr>
          </xsl:for-each>
        </table>
      </body>
    </html>
  </xsl:template>

</xsl:stylesheet>

Output: An HTML page with a table listing all books.

Example 2: Filter and Sort Data¶

Filter items based on a condition and sort the results:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:output method="xml" indent="yes"/>

  <xsl:template match="/">
    <expensive-books>
      <!-- Select books over $30, sorted by price descending -->
      <xsl:for-each select="books/book[price > 30]">
        <xsl:sort select="price" data-type="number" order="descending"/>
        <book>
          <xsl:copy-of select="title"/>
          <xsl:copy-of select="price"/>
        </book>
      </xsl:for-each>
    </expensive-books>
  </xsl:template>

</xsl:stylesheet>

Example 3: Using Templates for Modular Code¶

Use templates to organize complex transformations:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:output method="html" indent="yes"/>

  <!-- Main template -->
  <xsl:template match="/">
    <html>
      <body>
        <xsl:apply-templates select="books/book"/>
      </body>
    </html>
  </xsl:template>

  <!-- Template for each book -->
  <xsl:template match="book">
    <div class="book">
      <h2><xsl:value-of select="title"/></h2>
      <p>By: <xsl:value-of select="author"/></p>
      <xsl:call-template name="format-price">
        <xsl:with-param name="amount" select="price"/>
      </xsl:call-template>
    </div>
  </xsl:template>

  <!-- Named template for price formatting -->
  <xsl:template name="format-price">
    <xsl:param name="amount"/>
    <p class="price">
      <xsl:text>Price: $</xsl:text>
      <xsl:value-of select="format-number($amount, '#,##0.00')"/>
    </p>
  </xsl:template>

</xsl:stylesheet>

Example 4: XML to JSON-like Structure¶

Convert XML to a JSON-friendly text format:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:output method="text"/>

  <xsl:template match="/">
    <xsl:text>[</xsl:text>
    <xsl:for-each select="books/book">
      <xsl:if test="position() > 1">,</xsl:if>
      <xsl:text>{"title":"</xsl:text>
      <xsl:value-of select="title"/>
      <xsl:text>","author":"</xsl:text>
      <xsl:value-of select="author"/>
      <xsl:text>","price":</xsl:text>
      <xsl:value-of select="price"/>
      <xsl:text>}</xsl:text>
    </xsl:for-each>
    <xsl:text>]</xsl:text>
  </xsl:template>

</xsl:stylesheet>

Example 5: Conditional Formatting¶

Apply different styles based on data values:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:output method="html" indent="yes"/>

  <xsl:template match="/">
    <html>
      <head>
        <style>
          .low-price { color: green; }
          .high-price { color: red; font-weight: bold; }
        </style>
      </head>
      <body>
        <xsl:for-each select="books/book">
          <p>
            <xsl:value-of select="title"/>:
            <span>
              <xsl:attribute name="class">
                <xsl:choose>
                  <xsl:when test="price &lt; 30">low-price</xsl:when>
                  <xsl:otherwise>high-price</xsl:otherwise>
                </xsl:choose>
              </xsl:attribute>
              $<xsl:value-of select="price"/>
            </span>
          </p>
        </xsl:for-each>
      </body>
    </html>
  </xsl:template>

</xsl:stylesheet>

Example 6: Grouping with Keys (XSLT 1.0 Muenchian Grouping)¶

Group items by a common value:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:output method="html" indent="yes"/>

  <!-- Key for grouping books by author -->
  <xsl:key name="books-by-author" match="book" use="author"/>

  <xsl:template match="/">
    <html>
      <body>
        <h1>Books by Author</h1>
        <!-- Select first book of each author group -->
        <xsl:for-each select="books/book[count(. | key('books-by-author', author)[1]) = 1]">
          <xsl:sort select="author"/>
          <h2><xsl:value-of select="author"/></h2>
          <ul>
            <!-- List all books by this author -->
            <xsl:for-each select="key('books-by-author', author)">
              <li><xsl:value-of select="title"/></li>
            </xsl:for-each>
          </ul>
        </xsl:for-each>
      </body>
    </html>
  </xsl:template>

</xsl:stylesheet>

Included Example Files¶

FreeXmlToolkit includes professional example stylesheets in the examples/xsl/ folder:

Stylesheet	Description
`FundsXML_Factsheet.xsl`	Generate a fund factsheet report
`FundsXML_ExecutiveSummary.xsl`	Create an executive summary
`FundsXML_DataQualityReport.xsl`	Data quality validation report
`FundsXML_PortfolioAnalysis.xsl`	Portfolio analysis with charts
`FundsXML_RiskReport.xsl`	Risk analysis report

Use these with the example XML file examples/xml/FundsXML_422_Bond_Fund.xml.

Performance Statistics¶

After each transformation, the OUTPUT panel's status line shows compact statistics in the form Transformed · N ms · M chars:

Execution time - How long the transformation took (milliseconds)
Output size - Size of the generated output (characters)

For detailed per-template timings, enable Profile run in the Transform panel's ⋮ menu - the next run also opens a read-only Profile tool tab.

Tips¶

Validate first - Make sure your XML and XSLT files are valid before transformation
Check the OUTPUT panel status - If a transformation fails, the red error status in the OUTPUT panel header shows the error message
Use the Preview view - For HTML output, the OUTPUT panel's Preview toggle shows you exactly how it will look
Try the example files - Learn from the included examples in the examples/ folder
Need more features? - Use the XSLT Developer for advanced editing

Next Steps¶

XSLT Developer - Full XSLT/XQuery development environment
PDF Generator (FOP) - Generate PDFs from XSL-FO stylesheets

Previous	Home	Next
XSD Validation	Home	XSLT Developer