- Sams Teach Yourself XML in 21 Days, Third Edition
- Table of Contents
- About the Author
- Acknowledgments
- We Want to Hear from You!
- Introduction
- Part I: At a Glance
- Day 1. Welcome to XML
- All About Markup Languages
- All About XML
- Looking at XML in a Browser
- Working with XML Data Yourself
- Structuring Your Data
- Creating Well-Formed XML Documents
- Creating Valid XML Documents
- How XML Is Used in the Real World
- Online XML Resources
- Summary
- Q&A
- Workshop
- Day 2. Creating XML Documents
- Choosing an XML Editor
- Using XML Browsers
- Using XML Validators
- Creating XML Documents Piece by Piece
- Creating Prologs
- Creating an XML Declaration
- Creating XML Comments
- Creating Processing Instructions
- Creating Tags and Elements
- Creating CDATA Sections
- Handling Entities
- Summary
- Q&A
- Workshop
- Day 3. Creating Well-Formed XML Documents
- What Makes an XML Document Well-Formed?
- Creating an Example XML Document
- Understanding the Well-Formedness Constraints
- Using XML Namespaces
- Understanding XML Infosets
- Understanding Canonical XML
- Summary
- Q&A
- Workshop
- Day 4. Creating Valid XML Documents: DTDs
- All About DTDs
- Validating a Document by Using a DTD
- Creating Element Content Models
- Commenting a DTD
- Supporting External DTDs
- Handling Namespaces in DTDs
- Summary
- Q&A
- Workshop
- Declaring Attributes in DTDs
- Day 5. Handling Attributes and Entities in DTDs
- Specifying Default Values
- Specifying Attribute Types
- Handling Entities
- Summary
- Q&A
- Workshop
- Day 6. Creating Valid XML Documents: XML Schemas
- Using XML Schema Tools
- Creating XML Schemas
- Dissecting an XML Schema
- The Built-in XML Schema Elements
- Creating Elements and Types
- Specifying a Number of Elements
- Specifying Element Default Values
- Creating Attributes
- Summary
- Q&A
- Workshop
- Day 7. Creating Types in XML Schemas
- Restricting Simple Types by Using XML Schema Facets
- Creating XML Schema Choices
- Using Anonymous Type Definitions
- Declaring Empty Elements
- Declaring Mixed-Content Elements
- Grouping Elements Together
- Grouping Attributes Together
- Declaring all Groups
- Handling Namespaces in Schemas
- Annotating an XML Schema
- Summary
- Q&A
- Workshop
- Part I. In Review
- Well-Formed Documents
- Valid Documents
- Part II: At a Glance
- Day 8. Formatting XML by Using Cascading Style Sheets
- Our Sample XML Document
- Introducing CSS
- Connecting CSS Style Sheets and XML Documents
- Creating Style Sheet Selectors
- Using Inline Styles
- Creating Style Rule Specifications in Style Sheets
- Summary
- Q&A
- Workshop
- Day 9. Formatting XML by Using XSLT
- Introducing XSLT
- Transforming XML by Using XSLT
- Writing XSLT Style Sheets
- Using <xsl:apply-templates>
- Using <xsl:value-of> and <xsl:for-each>
- Matching Nodes by Using the match Attribute
- Working with the select Attribute and XPath
- Using <xsl:copy>
- Using <xsl:if>
- Using <xsl:choose>
- Specifying the Output Document Type
- Summary
- Q&A
- Workshop
- Day 10. Working with XSL Formatting Objects
- Introducing XSL-FO
- Using XSL-FO
- Using XSL Formatting Objects and Properties
- Building an XSL-FO Document
- Handling Inline Formatting
- Formatting Lists
- Formatting Tables
- Summary
- Q&A
- Workshop
- Part II. In Review
- Using CSS
- Using XSLT
- Using XSL-FO
- Part III: At a Glance
- Day 11. Extending HTML with XHTML
- Why XHTML?
- Writing XHTML Documents
- Validating XHTML Documents
- The Basic XHTML Elements
- Organizing Text
- Formatting Text
- Selecting Fonts: <font>
- Comments: <!-->
- Summary
- Q&A
- Workshop
- Day 12. Putting XHTML to Work
- Creating Hyperlinks: <a>
- Linking to Other Documents: <link>
- Handling Images: <img>
- Creating Frame Documents: <frameset>
- Creating Frames: <frame>
- Creating Embedded Style Sheets: <style>
- Formatting Tables: <table>
- Creating Table Rows: <tr>
- Formatting Table Headers: <th>
- Formatting Table Data: <td>
- Extending XHTML
- Summary
- Q&A
- Workshop
- Day 13. Creating Graphics and Multimedia: SVG and SMIL
- Introducing SVG
- Creating an SVG Document
- Creating Rectangles
- Adobe's SVG Viewer
- Using CSS Styles
- Creating Circles
- Creating Ellipses
- Creating Lines
- Creating Polylines
- Creating Polygons
- Creating Text
- Creating Gradients
- Creating Paths
- Creating Text Paths
- Creating Groups and Transformations
- Creating Animation
- Creating Links
- Creating Scripts
- Embedding SVG in HTML
- Introducing SMIL
- Summary
- Q&A
- Workshop
- Day 14. Handling XLinks, XPointers, and XForms
- Introducing XLinks
- Beyond Simple XLinks
- Introducing XPointers
- Introducing XBase
- Introducing XForms
- Summary
- Workshop
- Part III. In Review
- Part IV: At a Glance
- Day 15. Using JavaScript and XML
- Introducing the W3C DOM
- Introducing the DOM Objects
- Working with the XML DOM in JavaScript
- Searching for Elements by Name
- Reading Attribute Values
- Getting All XML Data from a Document
- Validating XML Documents by Using DTDs
- Summary
- Q&A
- Workshop
- Day 16. Using Java and .NET: DOM
- Using Java to Read XML Data
- Finding Elements by Name
- Creating an XML Browser by Using Java
- Navigating Through XML Documents
- Writing XML by Using Java
- Summary
- Q&A
- Workshop
- Day 17. Using Java and .NET: SAX
- An Overview of SAX
- Using SAX
- Using SAX to Find Elements by Name
- Creating an XML Browser by Using Java and SAX
- Navigating Through XML Documents by Using SAX
- Writing XML by Using Java and SAX
- Summary
- Q&A
- Workshop
- Day 18. Working with SOAP and RDF
- Introducing SOAP
- A SOAP Example in .NET
- A SOAP Example in Java
- Introducing RDF
- Summary
- Q&A
- Workshop
- Part IV. In Review
- Part V: At a Glance
- Day 19. Handling XML Data Binding
- Introducing DSOs
- Binding HTML Elements to HTML Data
- Binding HTML Elements to XML Data
- Binding HTML Tables to XML Data
- Accessing Individual Data Fields
- Binding HTML Elements to XML Data by Using the XML DSO
- Binding HTML Tables to XML Data by Using the XML DSO
- Searching XML Data by Using a DSO and JavaScript
- Handling Hierarchical XML Data
- Summary
- Q&A
- Workshop
- Day 20. Working with XML and Databases
- XML, Databases, and ASP
- Storing Databases as XML
- Using XPath with a Database
- Introducing XQuery
- Summary
- Q&A
- Workshop
- Day 21. Handling XML in .NET
- Creating and Editing an XML Document in .NET
- From XML to Databases and Back
- Reading and Writing XML in .NET Code
- Using XML Controls to Display Formatted XML
- Creating XML Web Services
- Summary
- Q&A
- Workshop
- Part V. In Review
- Appendix A. Quiz Answers
- Quiz Answers for Day 1
- Quiz Answers for Day 2
- Quiz Answers for Day 3
- Quiz Answers for Day 4
- Quiz Answers for Day 5
- Quiz Answers for Day 6
- Quiz Answers for Day 7
- Quiz Answers for Day 8
- Quiz Answers for Day 9
- Quiz Answers for Day 10
- Quiz Answers for Day 11
- Quiz Answers for Day 12
- Quiz Answers for Day 13
- Quiz Answers for Day 14
- Quiz Answers for Day 15
- Quiz Answers for Day 16
- Quiz Answers for Day 17
- Quiz Answers for Day 18
- Quiz Answers for Day 19
- Quiz Answers for Day 20
- Quiz Answers for Day 21
Recommended Book
Recommended Book
Recommended Book
Writing XSLT Style Sheets
Now that you've seen three different places to create XSLT transformations—on a Web server, in a client browser, and using a standalone program—it's time to see how to create your own XSLT style sheets.
To work with XSLT, you have to know how XSLT views XML documents. In XSLT terms, an XML document is a tree of nodes. The tree starts with the root node, and it branches out from that point. The root node corresponds to the very beginning of the document; it's not the same as the document element. The root node corresponds to the very beginning of the document, so you have access to the document's prolog, which comes before the document element.
Each distinct item in an XML document is considered a node—comments, processing instructions, elements, even the text inside elements. From XSLT's point of view, there are seven types of nodes, and you're going to see how to build style sheets that use all of them:
- Attribute— An attribute.
- Comment— The text of a comment (excluding the <!-- and --> parts).
- Element— An element.
- Namespace— The namespace's URI.
- Processing instruction— The text of the processing instruction (excluding <? and ?>).
- Root node— The very start of the document, before even the document element. XSLT gives you access to the root node, which comes before the document element, in order to give you access to the prolog, such as the XML declaration.
- Text— The text of the node.
To handle and search the various nodes in XML documents, the XSLT specification defines a number of elements, just as you saw for XML schemas in Day 6, "Creating Valid XML Documents: XML Schemas." It also uses an XML-specific language, XML Path Language (XPath), to let you specify exactly what nodes you're looking for.
You'll see how this works by dissecting the style sheet ch09_02.xsl. You started that document with an XML declaration and by using the <xsl:stylesheet> element. (Note that this is not the <?xsl:stylesheet?> processing instruction you can use in XML documents to connect style sheets to XML documents.) In this element, you associate the xsl namespace with the URI " http://www.w3.org/1999/XSL/Transform ", which is the official namespace for XSLT:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
.
.
.
To indicate what elements you want to locate and work with, you use the <xsl:template> element to create an XSLT template. A template lets you match a node or nodes in the XML document and specify what you want to do with the contained data. For example, to match the document element <states> in the sample XML document, you can use this <xsl:template> element:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="states">
.
.
.
</xsl:template>
.
.
.
</xsl:stylesheet>
Now the XSLT processor will look through your XML document and match the <states> element to the template. Technically speaking, what's happening here is that when the XSLT processor opens the document, it starts at the root node and searches for templates that match the children of the root node, which means that <xsl:template match="states"> will match because <states> is a child of the root node; <xsl:template match="state"> would not match, however, because <state> is a grandchild of the root node.
In the sample template, you specify what you want the matched element to be replaced with in the formatted output document. For example, if you wanted to replace the document element, including all its child nodes, with the HTML <HTML><BODY><H1>Hello!</H1></BODY></HTML>, you could use this:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="states">
<HTML><BODY><H1>Hello!</H1></BODY></HTML>
</xsl:template>
.
.
.
</xsl:stylesheet>
Now the resulting output document will only hold <HTML><BODY><H1>Hello!</H1></BODY></HTML>. Although this shows how templates work, it's not too useful in itself. In the ch09_02.xsl example, you actually want to produce this kind of output:
<HTML>
<BODY>
<P>California</P>
<P>Massachusetts</P>
<P>New York</P>
</BODY>
</HTML>
To do this, you need to strip data out of the <state> elements in the XML document, and to do that, you can use some additional templates. Now that you've matched the <states> element, you can indicate that you want to match child nodes inside the <states> element by using additional templates. You indicate this by using the <xsl:apply-templates> element:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="states">
<HTML>
<BODY>
<xsl:apply-templates/>
</BODY>
</HTML>
</xsl:template>
.
.
.
</xsl:stylesheet>
This example says is that the XSLT processor should place <HTML><BODY> into the output document, followed by the results of applying any other templates in the style sheet that match the child nodes of the <states> node, followed by </BODY></HTML>.