Home > Articles > Web Services > XML

Sams Teach Yourself XML in 21 Days

Sep 16, 2005

📄 Contents

␡

⎙ Print

< Back Page 139 of 288 Next >

Recommended Book 

Sams Teach Yourself XML in 21 Days, 3rd Edition

Learn More Buy

The Basic XHTML Elements

To be able to use XHTML, you need to know what's available, so the following sections describe the basic XHTML elements and their attributes, with examples. These elements might look like HTML, but they're XHTML, which means they're really XML—and that means that there are rigid rules about which element can or must contain what other elements, which attributes are required, and so on. An HTML author should know these rules when making the transition to XHTML. The following sections list what versions of XHTML support each element and attribute (with the exception of XHTML 2.0, whose list of supported elements isn't even available yet). Let's start with the XHTML document element, <html>.

Using the Document Element: `<html>`

As you saw earlier today, the document element for all XHTML elements is <html>. This element must contain all other elements in an XHTML document. The <html> 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 the <html> element:

dir — Sets the direction of text that doesn't have an inherent direction, called 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.)
lang — Specifies the base language 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.)
xmlns — Is a required attribute that should be set to "http://www.w3.org/1999/xhtml". (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)

As you've already seen today, <html> is the document element for an XHTML document, and it looks like this:

<?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>
        .
        .
        .
    </body>
</html>

In HTML, the <HTML> tag is optional because it's the default, and browsers have long come to accept nearly any form of HTML markup. In XHTML, however, the <html> element is required as the document element.

The xmlns attribute is also required, and you use it to set the namespace for the document to "http://www.w3.org/1999/xhtml", as in today's example. The other attributes are optional.

In the XHTML DTDs, the <html> element is declared in such a way that it can contain a <head> element and a <body> element (or a <head> element and a <frameset> element in the XHTML 1.0 Frameset documents). The following section describes the <head> element.

Creating a Document Head: `<head>`

In an XHTML document, the <head> element contains the document's head, which holds data about the document, scripting elements, and other data not intended for direct display. In XHTML, every XHTML document should have a <head> element, and every <head> element must contain at least a <title> element. The <head> 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:

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.)
lang — Specifies the base language of the element. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
profile — Specifies the location of one or more profile URIs. (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've already seen a <head> element in the sample XHTML document:

<?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>
        .
        .
        .
</html>

XHTML specifies that the following elements may appear in the <head> element:

<base>
<isindex>
<link>
<meta>
<noscript>
<object>
<script>
<style>
<title>

The only one of these elements that's required in the <head> element is the <title> element, which is described in the following section.

Giving a Document a Title: `<title>`

The <title> element holds the title of the document. A browser displays the document's title in its title bar. The <title> element is supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1. Here are its attributes:

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.)
lang — Specifies the base language 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 XHTML DTDs say that "exactly one title is required per document." You've already seen how to use this element in the XHTML document ch11_02.html.

Giving a Document a Body: `<body>`

The document's body holds the document's content—all the data that the document is meant to display. The <body> element is supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, and XHTML 1.1. Here are this element's attributes:

alink — Sets the color of hyperlinks when they're being activated. This attribute was deprecated in HTML 4.0. (Supported in XHTML 1.0 Transitional and XHTML 1.0 Frameset.)
background — Specifies the URI of an image to be used for the browser's background. This attribute was deprecated in HTML 4.0. (Supported in XHTML 1.0 Transitional and XHTML 1.0 Frameset.)
bgcolor — Specifies the color of the browser's background. 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.)
link — Sets the color of hyperlinks that have not yet been visited. This attribute was deprecated in HTML 4.0. (Supported in XHTML 1.0 Transitional and XHTML 1.0 Frameset.)
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.)
text — Specifies the color of text in the document. This attribute was deprecated in HTML 4.0. (Supported in XHTML 1.0 Transitional and XHTML 1.0 Frameset.)
title — Specifies the title of the body. (Supported in XHTML 1.0 Strict, XHTML 1.0 Transitional, XHTML 1.0 Frameset, and XHTML 1.1.)
vlink — Specifies the color of hyperlinks that have been visited. This attribute was deprecated in HTML 4.0. (Supported in XHTML 1.0 Transitional and XHTML 1.0 Frameset.)
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've seen the <body> element in the sample XHTML document already:

<?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>
        .
        .
        .
    </head>

    <body>

           <h1>

               Long Live XHTML!

           </h1>

           This is an XHTML document.

           <br/>

           Pretty good, eh?

       </body>
</html>

A number of common attributes of the HTML <BODY> element were deprecated in HTML 4.0, so they are not part of either XHTML 1.0 Strict or XHTML 1.1. These attributes include such favorites as alink, background, bgcolor, link, text, and vlink. You're now supposed to use style sheets properties instead of these attributes. Listing 11.3 shows an example that assigns values to some of these properties.

Example 11.3. An XHTML Document That Uses Styles (`ch11_03.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 type="text/css">

               body {background: coral}

               a:link {color: black}

               a:active {color: green}

               a:visited {color: blue}

           </style>
    </head>

    <body>
        <h1>
            Long Live XHTML!
        </h1>
        This is an
        <a href="http://www.w3.org/MarkUp/">XHTML</a>.
        document.
        <br/>
        Pretty good, eh?
    </body>
</html>

Figure 11.5 shows the results of Listing 11.3. The W3C's idea in turning toward style sheets to handle the display is that it wants to separate the display details from the data details. That idea is reaching its zenith in XHTML 2.0, which doesn't support even the usual HTML display elements. Theoretically, this transition makes sense, but it has also delayed the acceptance of XHTML by HTML authors.

Figure 11.5 sing an embedded style sheet.

Note also that if a style sheet contains sensitive characters, such as < or &, you should use external style sheets, as you did on Day 8, "Formatting XML by Using Cascading Style Sheets," because the entire contents of an XHTML document is intended to be valid XML.

< Back Page 139 of 288 Next >

🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Privacy Notice

Overview

Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security

Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children

This site is not directed to children under the age of 13.

Marketing

Pearson may send or direct marketing communications to users, provided that

Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
Such marketing is consistent with applicable law and Pearson's legal obligations.
Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out

Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

As required by law.
With the consent of the individual (or their parent, if the individual is a minor)
In response to a subpoena, court order or legal process, to the extent permitted or required by law
To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
To investigate or address actual or suspected fraud or other illegal activities
To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links

This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020

Email Address