(Optional) XSLT with Class XslCompiledTransform

Recall from Section 19.7 that XSLT provides elements that define rules for converting one type of XML document to another type of XML document. We showed how to transform XML documents into XHTML documents and displayed these in Internet Explorer. The XSLT processor included in Internet Explorer (i.e., MSXML) performed the transformations.

Performing an XSL Transformation in C# Using the .NET Framework

Figure 19.30 applies the style sheet sports.xsl (Fig. 19.17) to sports.xml (Fig. 19.26) programmatically. The result of the transformation is written to an XHTML file on disk and displayed in a text box. Figure 19.30(c) shows the resulting XHTML document (sports.html) when it is viewed in Internet Explorer.

Figure 19.30. XSLT style sheet applied to an XML document.

 1 // Fig. 19.30: TransformTest.cs
 2 // Applying an XSLT style sheet to an XML document.
 3 using System;
 4 using System.Windows.Forms;
 5 using System.Xml.Xsl; // contains class XslCompiledTransform
 6
 7 namespace TransformTest
 8 {
 9 public partial class TransformTestForm : Form
10 {
11 public TransformTestForm()
12 {
13 InitializeComponent();
14 } // end constructor
15
16 // applies the transformation 
17 private XslCompiledTransform transformer;
18
19 // initialize variables
20 private void TransformTestForm_Load( object sender, EventArgs e )
21 {
22 transformer = new XslCompiledTransform(); // create transformer
23
24 // load and compile the style sheet
25 transformer.Load( "sports.xsl" ); 
26 } // end method TransformTestForm_Load
27
28 // transform XML data on transformButton_Click event
29 private void transformButton_Click( object sender, EventArgs e )
30 {
31 // perform the transformation and store the result in new file
32 transformer.Transform( "sports.xml", "sports.html" ); 
33
34 // read and display the XHTML document's text in a Textbox
35 consoleTextBox.Text = 
36  System.IO.File.ReadAllText( "sports.html" ); 
37 } // end method transformButton_Click
38 } // end class TransformTestForm
39 } // end namespace TransformTest
 

(a)

(b)

(c)

Line 5 is a using declaration for the System.Xml.Xsl namespace, which contains class XslCompiledTransform for applying XSLT style sheets to XML documents. Line 17 declares XslCompiledTransform reference transformer. An object of this type serves as an XSLT processor (like MSXML in earlier examples) to transform XML data from one format to another.

In event handler transformTestForm_Load (lines 2026), line 22 creates a new XslCompiledTransform object. Then line 25 calls the XslCompiledTransform object's Load method, which parses and loads the style sheet that this application uses. This method takes an argument specifying the name and location of the style sheetsports.xsl (Fig. 19.17) located in the current directory.

Event handler TRansformButton_Click (lines 2937) calls method transform of class XslCompiledTransform to apply the style sheet (sports.xsl) to sports.xml (line 32). This method takes two string argumentsthe first specifies the XML file to which the style sheet should be applied, and the second specifies the file in which the result of the transformation should be stored on disk. Thus the transform method call in line 32 transforms sports.xml to XHTML and writes the result to disk as the file sports.html. Figure 19.30(c) shows the new XHTML document rendered in Internet Explorer. Note that the output is identical to that of Fig. 19.16in the current example, though, the XHTML is stored on disk rather than generated dynamically by MSXML.

After applying the transformation, the program displays the content of the newly created sports.html file in the txtConsole TextBox, as shown in Fig. 19.30(b). Lines 3536 obtain the text of the file by passing its name to method ReadAllText of the System.IO.File class provided by the FCL to simplify file-processing tasks on the local system.

Preface

Index

    Introduction to Computers, the Internet and Visual C#

    Introduction to the Visual C# 2005 Express Edition IDE

    Introduction to C# Applications

    Introduction to Classes and Objects

    Control Statements: Part 1

    Control Statements: Part 2

    Methods: A Deeper Look

    Arrays

    Classes and Objects: A Deeper Look

    Object-Oriented Programming: Inheritance

    Polymorphism, Interfaces & Operator Overloading

    Exception Handling

    Graphical User Interface Concepts: Part 1

    Graphical User Interface Concepts: Part 2

    Multithreading

    Strings, Characters and Regular Expressions

    Graphics and Multimedia

    Files and Streams

    Extensible Markup Language (XML)

    Database, SQL and ADO.NET

    ASP.NET 2.0, Web Forms and Web Controls

    Web Services

    Networking: Streams-Based Sockets and Datagrams

    Searching and Sorting

    Data Structures

    Generics

    Collections

    Appendix A. Operator Precedence Chart

    Appendix B. Number Systems

    Appendix C. Using the Visual Studio 2005 Debugger

    Appendix D. ASCII Character Set

    Appendix E. Unicode®

    Appendix F. Introduction to XHTML: Part 1

    Appendix G. Introduction to XHTML: Part 2

    Appendix H. HTML/XHTML Special Characters

    Appendix I. HTML/XHTML Colors

    Appendix J. ATM Case Study Code

    Appendix K. UML 2: Additional Diagram Types

    Appendix L. Simple Types

    Index



    Visual C# How to Program
    Visual C# 2005 How to Program (2nd Edition)
    ISBN: 0131525239
    EAN: 2147483647
    Year: 2004
    Pages: 600

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