XSLT 2.0 in .NET - CodeProject

The .NET Framework provides XslCompiledTransform which is an XSLT processor 1.0. However this doesn't mean that we can’t work with XSLT 2.0 in .NET. This article is for folks who want to use XSLT 2.0 in .NET.

Download Saxon.zip - 5.75 MB

Introduction

The .NET Framework provides XslCompiledTransform which is an XSLT processor 1.0. However this doesn't mean that we can’t work with XSLT 2.0 in .NET. This article is for folks who want to use XSLT 2.0 in .NET.

XSLT 2.0 is richer than XSLT 1.0. Indeed, below some features of XSLT 2.0.

regular expressions
current date time and multiple functions on dates
grouping
xsl:function for camelcasing a string
string comparison
tokenize() and matches()
for … in … return
next-match
as attribute on basic processors

All the functions and the specifications are described on W3C. You can also find all the functions on w3schools.

Saxon is an XSLT and XQuery processor created by Michael Kay. There are open-source and also closed-source commercial versions. Versions exist for Java and .NET. In this tutorial we will use Saxon .NET API to illustrate how the XSLT processing is performed.

Using the code

Input

The XML file below contains a list of some cities, their country and the population count.

<?xml version="1.0" encoding="utf-8"?>

<cities>
  <city name="Milano" country="Italia" pop="1307495" />
  <city name="Paris" country="France" pop="2220140" />
  <city name="Bordeaux" country="France" pop="719489" />
  <city name="München" country="Deutschland" pop="1260391" />
  <city name="Lyon" country="France" pop="474946" />
  <city name="Venezia" country="Italia" pop="270801" />
  <city name="Delft" country="Holland" pop="94512" />
  <city name="Rotterdam" country="Holland" pop="607460" />
</cities>

Desired output

Generated at 22.12.2011 23:42:27

Position	Country	City List	Population
1	France	Paris, Bordeaux, Lyon	3.414575E6
2	Italia	Milano, Venezia	1.578296E6
3	Deutschland	München	1.260391E6
4	Holland	Delft, Rotterdam	701972

XSLT Processing

We will make an XSLT to transform this XML file into an HTML report containing the list of countries ordered by population count and for each country the list of its cities grouped.

In the XSLT below, I used xsl:for-each-group statement in order to group the cities by country.

It is possible to set up the grouping in XSLT 1.0 by using xsl:key but It would be more complex.

Also, you will notice that I used current-dateTime() function in order to retrieve the current date time and format-dateTime() function in order to format the current date time.

<?xml version="1.0" encoding="iso-8859-1"?>

<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="html" indent="yes" encoding="iso-8859-1" />

  <xsl:template match="/">
    <html>
      <head>
        <title>Cities</title>
      </head>
      <body>
        Generated at
        <xsl:value-of select="format-dateTime(current-dateTime(), '[D].[M].[Y] [H]:[m]:[s]' )" />
        <br />
        <table style="border : 1px solid #000;">
          <thead>
            <tr>
              <th>Position</th>
              <th>Country</th>
              <th>City List</th>
              <th>Population</th>
            </tr>
          </thead>
          <tbody>
            <xsl:for-each-group select="cities/city" group-by="@country">
              <xsl:sort select="sum(current-group()/@pop)" data-type="number" order="descending" />
              <tr>
                <td>
                  <xsl:value-of select="position()" />
                </td>
                <td>
                  <xsl:value-of select="@country" />
                </td>
                <td>
                  <xsl:value-of select="current-group()/@name" separator=", " />
                </td>
                <td>
                  <xsl:value-of select="sum(current-group()/@pop)" />
                </td>
              </tr>
            </xsl:for-each-group>
          </tbody>
        </table>
      </body>
    </html>
  </xsl:template>
</xsl:stylesheet>

The code below performs the main XSLT processing by using the SAXON .NET API.

namespace Saxon
{
    internal class Program
    {
        private static void Main()
        {
            const string xmlFile = @"..\..\cities.xml";
            const string xsltFile = @"..\..\cities.xslt";
            const string outFile = @"..\..\cities_grouped.html";

            try
            {
                using (XmlReader xml = XmlReader.Create(xmlFile))
                using (XmlReader xslt = XmlReader.Create(xsltFile))
                {
                    // Create a Processor instance
                    var processor = new Processor();

                    // Load the source document
                    XdmNode input = processor.NewDocumentBuilder().
                        Build(xml);

                    // Create a transformer for the stylesheet
                    XsltTransformer transformer = processor.NewXsltCompiler().
                        Compile(xslt).Load();

                    // Set the root node of the source document to be the initial context node
                    transformer.InitialContextNode = input;

                    // Create a serializer
                    var serializer = new Serializer();
                    serializer.SetOutputStream(new FileStream(outFile, FileMode.Create, FileAccess.Write));

                    // Transform the source XML
                    transformer.Run(serializer);

                    Console.WriteLine("Output written to " + outFile + Environment.NewLine);
                }
            }
            catch (Exception e)
            {
                ConsoleColor currentConsoleColor = Console.ForegroundColor;
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine("oops : " + e.Message);
                Console.ForegroundColor = currentConsoleColor;
            }

            Console.Write("Press any key to exit ...");
            Console.ReadKey();
        }
    }
}

Other options

There is XQSharp, an XSLT, XPath 2.0 and XQuery 1.0 implementation for the .NET platform. And there is AltovaXML, an XSLT 2.0 and XQuery 1.0 COM based software package for Windows that can be used with .NET too (via COM Interop).