Microsoft KB Archive/300934

Knowledge Base

How to apply an XSL Transformation to XML for streaming by using Visual Basic .NET

Article ID: 300934

Article Last Modified on 3/29/2007

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APPLIES TO

• Microsoft Visual Basic .NET 2002 Standard Edition
• Microsoft Visual Basic .NET 2003 Standard Edition

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This article was previously published under Q300934

For a Microsoft Visual C# .NET version of this article, see 307494.

For a Microsoft Visual C++ .NET version of this article, see 815655.

IN THIS TASK

SUMMARY

• Requirements
• How to apply XSL Transformations
• Complete code sample

REFERENCES

SUMMARY

This article describes how to apply the Extensible Stylesheets Language (XSL) Transformations (XSLT) language to an Extensible Markup Language (XML) document by using the XslTransform class to create a new XML document. XSL is an XML-based language that is designed to transform either an XML document into another XML document or an XML document into any other structured document.

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Requirements

The following list outlines the recommended hardware, software, network infrastructure, and service packs that you need:

• Microsoft Visual Studio .NET
• Microsoft Visual Studio .NET Software Development Kit (SDK) QuickStarts

This article assumes that you are familiar with the following topics:

• XML terminology
• Creating and reading an XML file
• XML Path Language (XPath) syntax
• XSL

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How to apply XSL Transformations

This example uses two files named Books.xml and Books.xsl. You can create your own Books.xml and Books.xsl files or use the sample files that are included with the .NET Software Development Kit (SDK) QuickStarts.

1. Create a new Console Application in Visual Basic .NET.
2. Make sure that the project contains a reference to the System.Xml namespace, and add a reference if it does not.

3. Use the Imports statement on the Xml, XPath, and Xsl namespaces so that you are not required to qualify declarations in those namespaces later in your code. You must use the Imports statement prior to any other declarations:

   Imports System.Xml
   Imports System.Xml.XPath
   Imports System.Xml.Xsl
                       

4. Declare the appropriate variables. Declare an XPathDocument object to hold the XML document and an XslTransform object to transform XML documents. Add the declaration code in the Main procedure of Module1:

   Dim myXslTransform As XslTransform
   Dim myXPathDocument As XPathDocument
                       

5. Populate an XPathDocument object with the sample file, Books.xml. The XPathDocument class provides a fast and performance-oriented cache to process XML documents using XSLT. The XPathDocument class is similar to an XML Document Object Model (DOM) but is highly optimized for XSLT processing and the XPath data model.

   'Open the XML.  
   myXPathDocument = New XPathDocument("books.xml")
                       

6. Construct a new XslTransform object. The XslTransform class is an XSLT processor that implements the XSL Transformations (XSLT) version 1.0 recommendation:

   myXslTransform = New XslTransform()
                       

7. Use the Load method to load the XslTransform object with the style sheet. This style sheet transforms the details of the Books.xsl document into a simple International Standard Book Number (ISBN) list of books:

   myXslTransform.Load("books.xsl")
                       

8. Create an XmlTextWriter class with the new, transformed XML file name. Call the Transform method to initiate the transformation.

   Dim writer as XmlTextWriter
   writer = New XmlTextWriter("ISBNBooks.xml",System.Text.Encoding.UTF8)
   myXslTransform.Transform(myXPathDocument,Nothing, writer)
   writer.Flush()
   writer.Close()
                       

9. Alternately, you can send the transformed XML document into an XmlReader, Stream, or TextWriter class. The following code sample sends the XML transformation to an instance of the StringWriter (a derivative of TextWriter), which in turn writes the transformation to the console window.

   Dim stWrite As System.IO.StringWriter = New System.IO.StringWriter()
   myXslTransform.Transform(myXPathDocument, Nothing, stWrite)
   Console.WriteLine(stWrite.ToString)
   Console.ReadLine() 'Pause
                           

   NOTE: The complete code listing uses the preceding code instead of the code in step 8.

10. Build and run your project.The results of the transformation are displayed in the console window as follows:

       <root><bookstore><book ISBN="1-861003-11-0"><price>8.99</price>
                </book><book ISBN="0-201-63361-2"><price>11.99</price>
                </book><book ISBN="1-861001-57-6"><price>9.99</price>
                </book></bookstore></root>
                        

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Complete code listing

Imports System.Xml
Imports System.Xml.XPath
Imports System.Xml.Xsl
Module Module1

    Sub Main()
        Dim myXslTransform As XslTransform
        Dim myXPathDocument As XPathDocument
        myXPathDocument = New XPathDocument("books.xml")
        myXslTransform = New XslTransform()
        myXslTransform.Load("books.xsl")
        Dim stWrite As System.IO.StringWriter = New System.IO.StringWriter()
        myXslTransform.Transform(myXPathDocument, Nothing, stWrite)
        Console.WriteLine(stWrite.ToString)
        Console.ReadLine()
    End Sub

End Module 
                

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REFERENCES

For more information about the XslTransform class, see the following Microsoft .NET Framework Class Library documentation:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfSystemXmlXslXslTransformClassTopic.asp

For more information about the XslTransform class with the XslTransform object, see the following Microsoft .NET Framework Developer's Guide documentation:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconXSLTTransformationsWithXslTransformClass.asp

For a practical comparison of XSLT and Active Server Pages .NET, see the following MSDN Voices Extreme XML column:

http://msdn2.microsoft.com/en-us/library/ms950754.aspx

For more information about XML in .NET, see the ".NET Framework XML Classes and C# Offer Simple, Scalable Data Manipulation" article from MSDN Magazine at the following Microsoft Web site:

http://msdn.microsoft.com/msdnmag/issues/01/01/xml/

For more general information about Visual Basic .NET or XML in .NET, see the following Usenet newsgroups:

microsoft.public.dotnet.languages.vb

microsoft.public.dotnet.xml

For more information, refer to the following book:

R. Allen Wyke, Sultan Rehman, Brad Leupen, XML Programming (Core Reference), http://www.microsoft.com/mspress/books/sampchap/4798.aspx Microsoft Press, 2001

For more information, refer to the following Microsoft Training & Certification course:

Microsoft Corporation 2500 Introduction to XML and the Microsoft .NET Platform

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Additional query words: dotnet xml

Keywords: kbhowtomaster KB300934

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