XHTML documents have a simple, common structure that forms the basis for designing all
Web pages. This basic structure of tags is shown in the following listing with associated tags
described in the following sections.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD/XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml11-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>A Web Page</title>
</head>
<body>
. page content goes here
.
</body>
</html>
As you begin coding an XHTML page you can start with this template. In fact, you may wish to
create this document and save it as a template file. Then, when you start a new page, simply open
this document, save it under the name of the new page, and continue coding for the particular
information to appear on that page.
The Prolog
As meantioned previously all XHTML documents should begin with the prolog lines
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD/XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml11-transitional.dtd">
The first line indicates that this document is based on XML version 1.0 standards. The following
lines point to the Document Type Definition against which page coding will be validated.
The <html> Tag
The <html>...</html> container tag surrounds
all XHTML coding in the document. This tag indicates that the enclosed information contains XHTML coding
and should be rendered as such in the browser. In conformance with XHTML standards, the opening tag
includes a reference to the location namespace of the validation standards to be applied to this
document, along with attributes that specify the language used (English in this case):
The <head>...</head> container tag encloses
the head section of the XHTML document. The head section supplies a title for the document (see below)
along with other information related to formatting and indexing of the document. For present purposes,
only a title appears in the head section. Other tags that can be included in the head section are
discussed as needed.
The <title> Tag
The <title>...</title> container tag gives a
title to the document. This tag encloses a string of text that appears in the browser's Title
Bar when the page is opened. The <title> tag is
optional but provides helpful identification information to the person visiting the various pages of
your Web site.
The <body> Tag
The bulk of the coding of an XHTML document appears in the body section surrounded by the
<body>...</body> container tag. Only information
appearing inside this tag is displayed in the browser window. In its simplest form, the body section
contains plain text that is displayed in the default font style inside the browser window. Browsers
normally display text using Times New Roman font face at approximately 12-point size.
All Web pages begin with this basic document structure. Then the <body>
of the document is expanded with text and other page elements that are to be displayed inside
the browser window. Various arrangements of these display elements and control over their appearance are
accomplished by enclosing them within additional XHTML tags. As you proceed through this tutorial
you will learn these tags and associated attributes to produce Web pages of virtually any design
and content you desire.
Coding XHTML Documents
As a Web page author you begin your work by composing an XHTML document containing
the information you wish to appear on a Web page. This document is created on your desktop
PC.
In order to view your work it is not necessary to be connected to the Internet or to be linked
to a server on the World Wide Web. You can do all your work locally. If you happen to have an
account with an Internet Service Provider (ISP) that provides personal home directories,
then you can copy documents to your directory for viewing on the Web. For purposes of this
tutorial, though, you can create Web pages on your computer's hard drive or diskette and
view the pages through your browser.
Choosing a Browser
Most of the Web pages created in these tutorials work correctly under either Microsoft Internet
Explorer or Netscape Navigator. You should download the latest versions of these browsers.
Differences between the browsers and their renderings of Web pages are described as necessary.
The tutorials themselves were written to work under Internet Explorer.
Text Editing with Notepad
XHTML documents are created with text editors or with special HTML editors designed for
that purpose. For these tutorials it is sufficient to use a simple text editor such as Windows
Notepad. This program is usually found under the Start-->All Programs-->Accessories
menu. After opening this application, you enter the text and other page elements that you wish to
display, surrounding them with XHTML tags for layout and styling.
The following illustration shows the Notepad application with coding for a very simple
Web page. The page has a title that appears in the browser's Title Bar and a single sentence
that appears in the browser window.
Text and coding is typed into the editor in free-format style. That is, blank spaces, tabs, indents,
and other document editing techniques can, and should, be used to make the document readable in
the editor. These editing layouts are ignored by the browser, which only pays attention to the XHTML
tags for page layout and formatting instructions. The above code, for example, would be displayed
properly in the browser if it were entered in the editor 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/xhtml11-transitional.dtd">
<html><head xmlns="Http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><title>A Web Page</title></head><body>Page contents go here.
</body></html>
However, it is easier to compose and edit the document and to understand the layout of the
page by spacing its tags and text in a more readable format. This is an important
consideration. Take great care in alignment and indention of code so that visually it represents
the structure of content that displays in the browser. Sloppy code inevitably leads to errors. You
should choose a monospace font such as Courier New for displaying your
code in Notepad. The monospace font will better able you to align lines of text in the editor.
XHTML coding is an exacting art and science. Accuracy of coding is paramount and you need to work
with close to 100% accuracy. The browser doesn't know what you "wish" to do; it can only do what you
explicitly tell it. At first, coding will be tedious and time consuming. As you gain practice, though,
you should be able to type and edit XHTML code with not much more difficulty than straight text.
Saving an XHTML Document
Once you have completed coding the XHTML document you need to save it so that it can be
retrieved and displayed inside a browser. The document can be saved to a diskette or you can
create a folder on your hard drive for storing Web documents.
You can choose any file name you wish for your Web document, although you should
not include any blank spaces or special characters in the name. You also need to make sure
that you save the document with the .htm file extension. This extension identifies
the document as a Web page and is needed for the browser to recognize it as such. If you are using
Windows Notepad as your editor, make sure you select All Files (*.*) from
the drop-down menu as the file type. Otherwise, Notepad adds an extra ".txt"
extension to the file name and the document will not be recognized properly by the browser.
Text Editing with WordPad
Some Web page authors prefer to use Windows WordPad rather than Notepad for XHTML editing.
WordPad gives you a few more editing options such as font display choices and tab settings. HTML
should be edited under a monospaced font such as Courier New at 9-point font size; 1/4 inch (.25) tab
settings give good visible indentation for the document. The editing process is virtually the same
as with Notepad.
When saving a document with WordPad there are several choices of file formats. Be sure you save
the document with the .htm file extension and that it is saved as a
"Text Document" file type.
Displaying an XHTML Document
The saved HTML document with the .htm extension is now ready
to be viewed in your browser. You can open the document directly in the browser by double-clicking
its icon, or you can open your browser and use the File menu to navigate to the correct drive,
folder, and document. When the document is loaded into the browser, the address appearing in the
Address, or Location, box of your browser indicates this path to the document.
Document Editing and Display
When composing a lengthly Web page, it is not necessary to code the entire page at one time.
You can code a few lines, save the document, view the page in the browser, and then return to
composing the next section of code. In other words, you can switch back and forth between
the editor and the browser as you put together your Web page. Just remember to start with the
document structure described earlier so that you are editing a complete, valid Web document.
To facilitate this sort of page development, leave both your editor and browser open on
the desktop so that they are accessible in the Task Bar. Then you can making changes or
corrections to your document and switch immediately to your browser to refresh and view the
updated page.
The following illustration shows the computer screen with both Notepad and Internet Explorer
opened at the same time on the desktop. It is now a simple matter of clicking in the Notepad window
to edit the Web document. After saving the changes click in the Internet Explorer window and click
the "Refresh" button to reload the changed document. Then switch back to Notepad to continue with
page development.