- 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
Organizing Text
When you want to organize text in an XHTML document, things work very much as they do in HTML. As you've seen, you can place simple text with other elements—in other words, you can use mixed-content models in XHTML:
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title> An XHTML Document </title> </head> <body> <h1> Long Live XHTML! </h1> This is an XHTML document. <br/> Pretty good, eh? </body> </html>
The five XML predefined entities also work in XHTML:
- & is the & character.
- ' is the ' character.
- > is the > character.
- < is the < character.
- " is the " character.
In fact, there are a great many more character entities in HTML 4.0; they are available at http://www.w3.org/TR/html4/sgml/entities.html, and they're supported in XHTML as well. Here's a sampling:
- Á is a Latin capital letter A with an acute accent.
- α is a Greek lowercase letter alpha.
- ¢ is a cents sign.
- € is a euro symbol.
- ∞ is an infinity symbol.
- — is an em dash.
- Π is a Greek uppercase letter pi.
- π is a Greek lowercase letter pi.
- ® is a registered trademark sign.
Creating Paragraphs: <p>
The <p> element lets you create block-level paragraphs in XHTML. Note that because <p> is a block-level element, you cannot display other block-level elements inside it. The main difference between <p> in HTML and <p> in XHTML is that in XHTML, every <p> tag needs a closing </p> tag, whereas closing </p> tags are not usually used in HTML. After you've created a paragraph using <p>, you can format it as you like by using style sheets.
The <p> element is supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1. Here are this element's attributes:
- align — Sets the alignment of the text. Possible values include left (the default), right, center, and justify. This attribute was deprecated in HTML 4.0. (Supported in XHTML 1.0 Transitional and XHTML 1.0 Frameset.)
- class — Sets the style class of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- dir — Sets the direction of directionally neutral text. This attribute can be set to ltr, for left-to-right text, or rtl, for right-to-left text. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- id — Specifies the ID with which to refer to the element. You should set this attribute to a unique identifier. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- lang — Sets the base language of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- style — Indicates how a browser should display the element. You should set this to an inline style. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- title — Specifies the title of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- xml:lang — Specifies the base language for the element when the document is treated as XML. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
Paragraphs are the most basic block elements for text. A browser usually adds some space before and after paragraphs to separate them from other elements, but note that the actual handling varies by browser. Listing 11.4 shows an example that uses both line breaks and paragraphs.
Example 11.4. An XHTML Document That Uses Paragraphs and Line Breaks (ch11_04.html)
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title> An XHTML Document </title> </head> <body> <h1> Long Live XHTML! </h1> <p> This is an XHTML document. </p> Pretty good, eh? <br/> For more information, see <a href="http://www.w3.org/MarkUp/">XHTML</a>. </body> </html>
Figure 11.6 shows the XHTML document from Listing 11.4. This example points out the difference between <p> and <br>. The <p> element contains text and makes it into a block-level element; the browser normally uses vertical space to offset it from other elements. The <br> element is an empty element that just makes the browser skip to the next line. You can style the text in a <p> element by styling that element, but you can't style text by using the <br> element.
Figure 11.6 sing paragraphs and line breaks.
Skipping a Line: <br>
In XHTML, the <br> element is an empty element that inserts a line break in text, and you use it like this in XHTML:
<br />
This element is supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1. Here are the attributes of this element:
- class — Sets the style class of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- clear — Is used to move past other content. You can set this attribute to none, left, right, or all. (Supported in XHTML 1.0 Transitional and XHTML 1.0 Frameset.)
- id — Specifies the ID with which to refer to the element. You should set this attribute to a unique identifier. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- style — Indicates how a browser should display the element. You should set this to an inline style. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- title — Specifies the title of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1. )
Using this element as <br/> in XHTML doesn't cause any problems in the major browsers.
Centering Text: <center>
While HTML was growing up, the <center> element was a very popular one. You could use this element to center text and other content in Web pages. Like many other elements and attributes, <center> was deprecated in HTML 4.0 in favor of style sheets, which means that it's only supported in XHTML 1.0 Transitional and XHTML 1.0 Frameset; you won't find it in the XHTML 1.0 Strict, XHTML 1.1, or XHTML 2.0 DTDs. Here are the attributes of this element:
- class — Sets the style class of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- dir — Sets the direction of directionally neutral text. This attribute can be set to ltr, for left-to-right text, or rtl, for right-to-left text. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- id — Specifies the ID with which to refer to the element. You should set this attribute to a unique identifier. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- lang — Sets the base language of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- style — Indicates how a browser should display the element. You should set this to an inline style. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- title — Specifies the title of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- xml:lang — Specifies the base language for the element when the document is treated as XML. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1. )
Although it has been deprecated, the <center> element is still a very popular one, and it's built into XHTML 1.0 Transitional and XHTML 1.0 Frameset. Listing 11.5 shows an example of using this element in the document ch11_05.html.
Example 11.5. An XHTML Document That Uses the <center> Element (ch11_05.html)
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title> An XHTML Document </title> </head> <body> <center> <h1> Long Live XHTML! </h1> This is an XHTML document. <br/> Pretty good, eh? <br/> For more information, see <a href="http://www.w3.org/MarkUp/">XHTML</a>. </center> </body> </html>
Figure 11.7 shows what this XHTML document looks like in a browser.
Figure 11.7 entering text by using the <center> element.
Even though the <center> element is still popular, it has been deprecated. So how are you supposed to center text now? You can use the <div> element with style sheets, as described in the next section.
Styling Block Content: <div>
In XHTML you use the <div> element to enclose sections of text or other elements. This lets you style that content as you like. This element is supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1. Here are its attributes:
- align — Specifies the horizontal alignment of the element. This attribute can be set to left (the default), right, center, or justify. This attribute was deprecated in HTML 4.0. (Supported in XHTML 1.0 Transitional and XHTML 1.0 Frameset.)
- class — Sets the style class of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- dir — Sets the direction of directionally neutral text. This attribute can be set to ltr, for left-to-right text, or rtl, for right-to-left text. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- id — Specifies the ID with which to refer to the element. You should set this attribute to a unique identifier. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- lang — Sets the base language of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- style — Indicates how a browser should display the element. You should set this to an inline style. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- title — Specifies the title of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- xml:lang — Specifies the base language for the element when the document is treated as XML. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
The W3C says that you should use the align attribute of the <div> element to align text. Listing 11.6 shows an example of this.
Example 11.6. An XHTML Document That Uses the <div> Element (ch11_06.html)
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title> An XHTML Document </title> </head> <body> <div align="center"> <h1> Long Live XHTML! </h1> This is an XHTML document. <br/> Pretty good, eh? <br/> For more information, see <a href="http://www.w3.org/MarkUp/">XHTML</a>. </div> </body> </html>
This XHTML document gives the same results as shown in Figure 11.7. That's fine, but the W3C seems to have forgotten that it deprecated the align attribute in HTML 4.0. To be consistent with the way the W3C has been changing things, you should use a style sheet to style the <div> element. Listing 11.7 shows an example of this that gives the same results as Listing 11.6.
Example 11.7. An XHTML Document That Uses the <div> Element and Styles (ch11_07.html)
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title> An XHTML Document </title> <style> div {text-align: center} </style> </head> <body> <div> <h1> Long Live XHTML! </h1> This is an XHTML document. <br/> Pretty good, eh? <br/> For more information, see <a href="http://www.w3.org/MarkUp/">XHTML</a>. </div> </body> </html>
You can also position text and other content by using the positioning style properties and the <div> element that you saw on Day 6, "Creating Valid XML Documents: XML Schemas." Besides <div>, there's another element you can use in XHTML for styling—<span>, which you can use for inline styling.
Styling Inline Content: <span>
You can use the <span> element to apply inline styles in XHTML. This element is supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1. Here are the attributes of this element:
- class — Sets the style class of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- dir — Sets the direction of directionally neutral text. This attribute can be set to ltr, for left-to-right text, or rtl, for right-to-left text. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- id — Specifies the ID with which to refer to the element. You should set this attribute to a unique identifier. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- lang — Sets the base language of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- style — Indicates how a browser should display the element. You should set this to an inline style. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- title — Specifies the title of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- xml:lang — Specifies the base language for the element when the document is treated as XML. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
Listing 11.8 shows an example of using the <span> element. This example formats the word XHTML in red italics (see Figure 11.8).
Example 11.8. An XHTML Document That Uses the <span> Element (ch11_08.html)
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title> An XHTML Document </title> <style> span {color: red; font-style: italic} </style> </head> <body> <div> <h1> Long Live XHTML! </h1> This is an <span>XHTML</span> document. <br/> Pretty good, eh? <br/> For more information, see <a href="http://www.w3.org/MarkUp/">XHTML</a>. </div> </body> </html>
Figure 11.8 Using inline formatting.
The <div> and <span> elements are more important in XHTML than they are in HTML because of the reliance on style sheets to handle formatting in XHTML. By handling block styling, the <div> element replaces elements such as <center> in XHTML 1.0 Strict and XHTML 1.1, and by handling inline styling, <span> replaces elements such as <font>.
Creating Headings: <h1> to <h6>
Headings are block elements that present text in bold font of various sizes, allowing you to organize that text into sections. Using headings lets you break up the text flow in XHTML documents. As in HTML, the <h1> through <h6> elements create headings; <h1> creates the largest text and <h6> the smallest. These elements are supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1. Here are the possible attributes of these elements:
- align — Specifies the horizontal alignment of the element. This attribute can be set to left (the default), right, center, or justify. It was deprecated in HTML 4.0. (Supported in XHTML 1.0 Transitional and XHTML 1.0 Frameset.)
- class — Sets the style class of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- dir — Sets the direction of directionally neutral text. This attribute can be set to ltr, for left-to-right text, or rtl, for right-to-left text. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- id — Specifies the ID with which to refer to the element. You should set this attribute to a unique identifier. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- lang — Sets the base language of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- style — Indicates how a browser should display the element. You should set this to an inline style. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- title — Specifies the title of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
- xml:lang — Specifies the base language for the element when the document is treated as XML. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
You can see the six heading elements <h1>, <h2>, <h3>, <h4>, <h5>, and <h6> at work in Listing 11.9.
Example 11.9. An XHTML Document That Uses Headings (ch11_09.html)
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title> Using Headings </title> <style> div {text-align: center} </style> </head> <body> <div> <h1>Here is an <h1> heading</h1> <h2>Here is an <h2> heading</h2> <h3>Here is an <h3> heading</h3> <h4>Here is an <h4> heading</h4> <h5>Here is an <h5> heading</h5> <h6>Here is an <h6> heading</h6> </div> </body> </html>
Figure 11.9 shows this XHTML document in a browser.
Figure 11.9 Using headings in XHTML.