How to apply an XSLT Stylesheet in C#

I found a possible answer here: http://web.archive.org/web/20130329123237/http://www.csharpfriends.com/Articles/getArticle.aspx?articleID=63

From the article:

XPathDocument myXPathDoc = new XPathDocument(myXmlFile) ;
XslTransform myXslTrans = new XslTransform() ;
myXslTrans.Load(myStyleSheet);
XmlTextWriter myWriter = new XmlTextWriter("result.html",null) ;
myXslTrans.Transform(myXPathDoc,null,myWriter) ;

Edit:

But my trusty compiler says, XslTransform is obsolete: Use XslCompiledTransform instead:

XPathDocument myXPathDoc = new XPathDocument(myXmlFile) ;
XslCompiledTransform myXslTrans = new XslCompiledTransform();
myXslTrans.Load(myStyleSheet);
XmlTextWriter myWriter = new XmlTextWriter("result.html",null);
myXslTrans.Transform(myXPathDoc,null,myWriter);

Based on Daren's excellent answer, note that this code can be shortened significantly by using the appropriate XslCompiledTransform.Transform overload:

var myXslTrans = new XslCompiledTransform(); 
myXslTrans.Load("stylesheet.xsl"); 
myXslTrans.Transform("source.xml", "result.html"); 

(Sorry for posing this as an answer, but the code block support in comments is rather limited.)

In VB.NET, you don't even need a variable:

With New XslCompiledTransform()
    .Load("stylesheet.xsl")
    .Transform("source.xml", "result.html")
End With

Here is a tutorial about how to do XSL Transformations in C# on MSDN:

http://support.microsoft.com/kb/307322/en-us/

and here how to write files:

http://support.microsoft.com/kb/816149/en-us

just as a side note: if you want to do validation too here is another tutorial (for DTD, XDR, and XSD (=Schema)):

http://support.microsoft.com/kb/307379/en-us/

i added this just to provide some more information.

This might help you

public static string TransformDocument(string doc, string stylesheetPath)
{
    Func<string,XmlDocument> GetXmlDocument = (xmlContent) =>
     {
         XmlDocument xmlDocument = new XmlDocument();
         xmlDocument.LoadXml(xmlContent);
         return xmlDocument;
     };

    try
    {
        var document = GetXmlDocument(doc);
        var style = GetXmlDocument(File.ReadAllText(stylesheetPath));

        System.Xml.Xsl.XslCompiledTransform transform = new System.Xml.Xsl.XslCompiledTransform();
        transform.Load(style); // compiled stylesheet
        System.IO.StringWriter writer = new System.IO.StringWriter();
        XmlReader xmlReadB = new XmlTextReader(new StringReader(document.DocumentElement.OuterXml));
        transform.Transform(xmlReadB, null, writer);
        return writer.ToString();
    }
    catch (Exception ex)
    {
        throw ex;
    }

}   

I would like to share this small piece of code which reads from Database and transforms using XSLT. On the top I also have used xslt-extensions which makes it little different than others.

Note: This is just a draft code and may need cleanup before using in production.

var schema = XDocument.Load(XsltPath);
using (var connection = new SqlConnection(ConnectionString))
{
    connection.Open();
    using (var command = new SqlCommand(Sql, connection))
    {
        var reader = command.ExecuteReader();
        var dt = new DataTable(SourceNode);
        dt.Load(reader);
                    
        string xml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" + Environment.NewLine;
        using (var stringWriter = new StringWriter())
        {
            dt.WriteXml(stringWriter, true);
            xml += stringWriter.GetStringBuilder().ToString();
        }

        XDocument transformedXml = new XDocument();
        var xsltArgumentList = new XsltArgumentList();
        xsltArgumentList.AddExtensionObject("urn:xslt-extensions", new XsltExtensions());

        using (XmlWriter writer = transformedXml.CreateWriter())
        {
            XslCompiledTransform xslt = new XslCompiledTransform();
            xslt.Load(schema.CreateReader());
            xslt.Transform(XmlReader.Create(new StringReader(xml)), xsltArgumentList, writer);
        }
        var result = transformedXml.ToString();
    }
}

XsltPath is path to your xslt file.
ConnectionString constant is pointing to your database.
Sql is your query.
SourceNode is node of each record in source xml.

Now the interesting part, please note the use of urn:xslt-extensions and new XsltExtensions() in above code. You can use this if need some complex computation which may not be possible in xslt. Following is a simple method to format date.

public class XsltExtensions
{
    public string FormatDate(string dateString, string format)
    {
        DateTime date;

        if (DateTime.TryParse(dateString, out date))
            return date.ToString(format);

        return dateString;
    }
}

In XSLT file you can use it as below;

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:ext="urn:xslt-extensions">
...
<myTag><xsl:value-of select="ext:FormatDate(record_date, 'yyyy-MM-dd')"/></myTag>
...
</xsl:stylesheet>