1 Introduction to Web Development
CHAPTER 1
Introduction to Web Development
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2 Objectives Study the history of the World Wide Web
Review the basics of how to create Web pages
Work with structured Web pages
Study Web development
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3 Introduction to Web Development
In 1990 and 1991,Tim Berners-Lee created the World Wide Web at the European Laboratory for Particle
Physics (CERN) in Geneva, Switzerland
The original purpose of the World Wide Web (WWW) was to provide easy access to cross-referenced
documents that existed on the CERN computer network
Hypertext linking allows you to quickly open other Web pages
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4 Introduction to Web Development
A document on the Web is called a Web page
A Web page is identified by a unique address called the Uniform Resource Locator (URL)
A URL is also commonly referred to as a Web address
A URL is a type of Uniform Resource Identifier (URI)
A Web site refers to the location on the Internet of the Web pages and related files
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5 Introduction to Web Development
Web pages are displayed using a program called a Web browser
A Web server is a computer that delivers Web pages
The most popular Web server software is Apache HTTP Server (Apache)
The second most popular Web server is Microsoft Internet Information Services (IIS) for Windows
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6 HTML Documents
Web pages are created using Hypertext Markup Language (HTML)
Web pages are commonly referred to as HTML pages or documents
A markup language is a set of characters or symbols that define a document’s logical structure
HTML is based on an older language called Standard Generalized Markup Language (SGML)
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7 HTML Documents
Like SGML, HTML was originally designed as a way of defining the elements in a document independent
of how they would appear
HTML has evolved into a language that defines how elements should appear in a Web browser
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8 Basic HTML Syntax
HTML documents are text documents that contain formatting instructions called tags
HTML tags include:
Formatting commands (boldface or italic)
Controls that allow user input (option buttons or check boxes)
Tags are enclosed in brackets (< >) and consist of an opening tag and a closing tag
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9 Basic HTML Syntax
The closing tag must include a forward slash ( / ) immediately after the opening bracket
A tag pair and the data it contains are referred to as an element
The information contained within an element’s opening and closing tags is referred to as its content
Elements that do not require a closing tag are called empty elements
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10 Basic HTML Syntax Table 1-1 Common HTML elements
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11 Basic HTML Syntax
HTML documents must have a file extension of .html or .htm
All HTML documents must use the <html> element as the root element
A root element contains all the other elements in a document
The <head> element contains information that is used by the Web browser
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12 Basic HTML Syntax
A <head> element must contain a <title> element
The <head> element and the elements it contains are referred to as the document head
The <body> element and the text and elements it contains are referred to as the document body
The process by which a Web browser assembles or formats an HTML document is called parsing or
rendering
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13 Basic HTML Syntax Example:
<p><b>This paragraph will appear in boldface in a Web browser</b></p>
Parameters used to configure many HTML elements are called attributes
Insert line breaks using the paragraph <p> and line break <br> elements
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14 Basic HTML Syntax Sample HTML Code <html> <head>
<title>Toner Cartridge Sales</title>
</head>
<body>
<h1>Toner Cartridge Sales</h1>
<hr>
<h2>Lexmark Toner Cartridges</h2>
<img src="lexmark_logo.gif">
<p><b>Model #</b>:LEX <br>
<b>Compatibility</b>: Optra 4049/3112/3116<br>
<b>Price</b>: $189.99</p>
<p><b>Model #</b>:LEX <br>
<b>Compatibility</b>:Lexmark 4019/4028/4029<br>
<b>Price</b>:$209.00</p>
</body>
</html>
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15 Figure 1-1 A simple HTML document in a Web browser
Basic HTML Syntax
Figure 1-1 A simple HTML document in a Web browser
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16 Creating an HTML Document
HTML editors Macromedia Dreamweaver and Microsoft FrontPage are popular graphical interfaces that
create WYSIWYG (what-you-see-is-what-you-get) Web pages
You cannot use a Web browser to create an HTML document
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17 Web Communication Protocols
A Web page is identified by a unique address called the URL
Each URL consists of two basic parts:
A protocol (usually HTTP) and
Either the domain name for a Web server or a Web server’s Internet Protocol address
Hypertext Transfer Protocol (HTTP) manages the hypertext links that are used to navigate the Web
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18 Web Communication Protocols
A host refers to a computer system that is being accessed by a remote computer
A domain name is a unique address used for identifying a computer such as a Web server on the
Internet
The domain identifier identifies the type of institution or organization (.biz, .com, .edu, .org)
An Internet Protocol, or IP address, is another way to identify computers or devices connected to the
Internet
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19 Web Communication Protocols
An IP address consists of a series of four groups of numbers separated by periods
Each Internet domain name is associated with a unique IP address
HTTP is a component of Transmission Control Protocol/Internet Protocol (TCP/IP)
Hypertext Transfer Protocol Secure (HTTPS) provides secure Internet connections for transactions that
require security and privacy
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20 Web Communication Protocols
Protocol Domain name Directory Filename
Figure 1-4 Sample URL
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21 Publishing Your Web Site
Web Hosting:
The publication of a Web site for public access
Internet access (cable modem, DSL, satellite, dial-up modem, ISP)
Internet Service Provider (ISP):
Provides access to the Internet along with other types of services such as
America Online, CompuServe, and EarthLink
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22 Publishing Your Web Site
ISP advantages to hosting a Web site:
Extremely fast Internet connections using advanced fiber-optic connections
Large and powerful Web servers and the expertise and manpower to maintain and manage them
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23 Publishing Your Web Site
Domain name registration
Pick a domain name that is similar to your business name or that describes your Web site
You cannot use a domain name that is already in use or a trademarked name
Contact a domain name registrar to find out the availability of a domain name and register it
Domain names are stored in a master database that is maintained by the InterNIC
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24 Publishing Your Web Site
Domain name registration (continued)
For a fee, domain names can be registered for a specified period of time
A popular domain name registrar is Network Solutions
After you register your domain name, notify your ISP of your domain information
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25 Publishing Your Web Site
Figure 1-5 Network Solutions Web page
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26 Publishing Your Web Site
File Transfer Protocol (FTP)
Is a TCP/IP protocol used for transferring files across the Internet
Transfers files between an FTP client (your computer) and an FTP server (a server capable of running
FTP)
The vehicle that allows you to get your Web page files to the Web server
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27 Publishing Your Web Site
File Transfer Protocol (continued)
Your ISP provides a username and password to log on to the FTP site and upload files to the FTP server
Examples of FTP clients include Firefox and Internet Explorer
Allows you to use your browser to log on to an FTP server and upload your files
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28 Publishing Your Web Site
Figure 1-6 FTP Web site example
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29 Working with Well-Formed Web Pages
HTML became an Internet standard in 1993 with the release of version 1.0
The current version of HTML (4.01) was released in 1999
HTML 4.01 is the last version of the HTML language and is being replaced with extensible hypertext
markup language (XHTML)
HTML is not suitable for user agents other than Web browsers
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30 XHTML Document Type Definitions (DTDs)
A well-formed document must include:
<!DOCTYPE> declaration
<html>, <head>, and <body> elements
A document type definition (DTD) defines:
The elements and attributes that can be used in a document
The rules that a document must follow when it includes them
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31 XHTML Document Type Definitions (DTDs)
There are three types of DTDs with XHTML documents:
transitional
strict
frameset
The World Wide Web Consortium (W3C) was established in 1994 at MIT to oversee the development of
Web technology standards
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32 XHTML Document Type Definitions (DTDs)
The W3C:
Decided some common HTML elements and attributes for display and formatting would not be used in
XHTML 1.0
Recommended using Cascading Style Sheets (CSS) instead of HTML elements and attributes for
displaying and formatting Web pages
Elements and attributes that are considered obsolete and will eventually be eliminated are said to be
deprecated
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33 XHTML Document Type Definitions (DTDs)
Table 1-2 HTML elements that are deprecated in XHTML 1.0
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34 XHTML Document Type Definitions (DTDs)
Transitional DTD:
Allows you to use deprecated style elements in your XHTML documents
Use only if you need to create Web pages that use the deprecated elements
Frameset DTD:
Identical to the transitional DTD, except that it includes the <frameset> and <frame> elements
Allows you to split the browser window into two or more frames
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35 XHTML Document Type Definitions (DTDs)
Strict DTD:
Eliminates the elements that were deprecated in the transitional DTD and frameset DTD
The <!DOCTYPE> declaration for the strict DTD is as follows:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"
Always try to use the strict DTD
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36 Writing Well-Formed Documents
Include a <!DOCTYPE> declaration and the <html>, <head>, and <body> elements
All XHTML documents must use <html> as the root element
XHTML is case sensitive
All XHTML elements must have a closing tag
Attribute values must appear within quotation marks
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37 Writing Well-Formed Documents
Empty elements must be closed
XHTML elements must be properly nested
Nesting refers to how elements are placed inside other elements
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38 Cascading Style Sheets
A single piece of CSS formatting information, such as text alignment, is referred to as a style
The term cascading refers to the ability for Web pages to use CSS information from more than one
source
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39 Cascading Style Sheets
CSS properties:
CSS styles are created with two parts separated by a colon
The property refers to a specific CSS style
The value assigned to it determines the style’s visual characteristics
Together, a CSS property and the value assigned to it are referred to as a declaration or style declaration
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40 Cascading Style Sheets
Inline Styles
Allow you to add style information to a single element in a document
Internal Style Sheets
Create styles that apply to the entire document
P { color : blue }
selector { property : value }
External Style Sheets
A separate text document containing style declarations that are used by multiple documents on a Web
site
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41 Publishing Your Web Site
Create a content-type <meta> element to specify a content type that the document uses
The <meta> element provides information about the information in a Web page
The <meta> element is nested within the <head> section of the Web page
The three primary attributes in the <meta> element are: name, content, and http-equiv
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42 Validating Web Pages
A validating parser is a program that checks whether an XHTML document is well-formed and conforms
to a specific DTD
Validation verifies that your XHTML document is well formed and that the elements in your document
are correctly written
Validation can help you spot errors in your code
XHTML validating services can be found online
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43 Understanding Web Development
Web development, or Web programming, refers to the design of software applications for a Web site
The Webmaster is responsible for:
The day-to-day maintenance of a Web site
Monitoring Web site traffic and ensuring that the Web site’s hardware and software are running
properly
Knowledge of Web page design, authoring, and development
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44 Client/Server Architecture
Client (“front end”):
Presents an interface to the user
Gathers information from the user, submits it to a server, then receives, formats, and presents the
results returned from the server
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45 Client/Server Architecture
A three-tier, or multi-tier, client/server system consists of three distinct pieces:
Client tier, or user interface tier, is the Web browser
Processing tier, or middle tier, handles the interaction between the Web browser client and the data
storage tier
Performs necessary processing or calculations based on the request from the client tier
Handles the return of any information to the client tier
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46 Client/Server Architecture
Figure 1-16 The design of a three-tier client/server system
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47 JavaScript and Client-Side Scripting
JavaScript is:
A client-side scripting language that allows Web page authors to develop interactive Web pages and
sites
Used in most Web browsers including Firefox and Internet Explorer
Client-side scripting is a language that runs on a local browser (on the client tier) instead of on a Web
server (on the processing tier)
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48 JavaScript and Client-Side Scripting
JavaScript allows you to:
Turn static Web pages into applications such as games or calculators
Change the contents of a Web page after a browser has rendered it
Create visual effects such as animation
Control the Web browser window itself
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49 Server-Side Scripting and PHP
Server-side scripting refers to a scripting language that is executed from a Web server
Hypertext Preprocessor (PHP) is a server-side scripting language that is used to develop interactive Web
sites
Is easy to learn
Includes object-oriented programming capabilities
Supports many types of databases (MySQL, Oracle, Sybase, ODBC-compliant)
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50 Server-Side Scripting and PHP
PHP (continued):
PHP is an open source programming language
Open source refers to software where source code can be freely used and modified
Can’t access or manipulate a Web browser like JavaScript
Exists and executes solely on a Web server, where it performs various types of processing or accesses
databases
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51 Server-Side Scripting and PHP
General rule: Use client-side scripting to handle user interface processing and light processing, such as
validation; use server-side scripting for intensive calculations and data storage
Figure 1-17 How a Web server processes a PHP script
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52 Summary
In 1990 and 1991,Tim Berners-Lee created the World Wide Web at the European Laboratory for Particle
Physics (CERN)
Transmission Control Protocol/Internet Protocol (TCP/IP) is a large collection of communication
protocols used on the Internet
A Document Type Definition (DTD) defines the elements and attributes that can be used in a document
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53 Summary
Cascading Style Sheets (CSS) are a standard set by the W3C for managing the design and formatting of
Web pages in a Web browser
A system that consists of a client and a server is known as a two-tier system
A three-tier client/server system consists of the client tier, the processing tier, and the data storage tier
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54 Summary
JavaScript is a client-side scripting language that allows Web page authors to develop interactive Web
pages and sites
Hypertext Preprocessor (PHP) is a server-side scripting language that is used for developing interactive
Web sites
Open source refers to software for which the source code can be freely used and modified
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