Calling a .NET C# class from XSLT
- by HanSolo
If you've ever worked with XSLT, you'd know that it's pretty limited when it comes to its programming capabilities. Try writing a for loop in XSLT and you'd know what I mean. XSLT is not designed to be a programming language so you should never put too much programming logic in your XSLT. That code can be a pain to write and maintain and so it should be avoided at all costs. Keep your xslt simple and put any complex logic that your xslt transformation requires in a class.
Here is how you can create a helper class and call that from your xslt. For example, this is my helper class:
public class XsltHelper
{
public string GetStringHash(string originalString)
{
return originalString.GetHashCode().ToString();
}
}
And this is my xslt file(notice the namespace declaration that references the helper class):
<?xml version="1.0" encoding="UTF-8" ?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0" xmlns:ext="http://MyNamespace">
<xsl:output method="text" indent="yes" omit-xml-declaration="yes"/>
<xsl:template match="/">The hash code of "<xsl:value-of select="stringList/string1" />" is "<xsl:value-of select="ext:GetStringHash(stringList/string1)" />".
</xsl:template>
</xsl:stylesheet>
Here is how you can include the helper class as part of the transformation:
string xml = "<stringList><string1>test</string1></stringList>";
XmlDocument xmlDocument = new XmlDocument();
xmlDocument.LoadXml(xml);
XslCompiledTransform xslCompiledTransform = new XslCompiledTransform();
xslCompiledTransform.Load("XSLTFile1.xslt");
XsltArgumentList xsltArgs = new XsltArgumentList();
xsltArgs.AddExtensionObject("http://MyNamespace", Activator.CreateInstance(typeof(XsltHelper)));
using (FileStream fileStream = new FileStream("TransformResults.txt", FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite))
{
// transform the xml and output to the output file ...
xslCompiledTransform.Transform(xmlDocument, xsltArgs, fileStream);
}
