Appendix A Introduction to Web Development PHP Programming with MySQL

Appendix AIntroduction to Web DevelopmentPHP Programming with MySQL

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 • Hypertextlinking allows you to quickly open other Web pages PHP Programming with MySQL

HTML Documents • Web pages are created using Hypertext Markup Language (HTML) • Web pages are commonly referred to as HTMLpages 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) PHP Programming with MySQL

HTML Documents (continued) • 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 PHP Programming with MySQL

Basic HTML Syntax • HTMLdocuments 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 PHP Programming with MySQL

Basic HTML Syntax (continued) • 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 PHP Programming with MySQL

Basic HTML Syntax (continued) Table 1-1 Common HTML elements PHP Programming with MySQL

Basic HTML Syntax (continued) • 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 PHP Programming with MySQL

Basic HTML Syntax (continued) • 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 PHP Programming with MySQL

Basic HTML Syntax (continued) • Example: This paragraph will appear in boldface in a Web browser • Parameters used to configure many HTML elements are called attributes • Insert line breaks using the paragraph and line break elements PHP Programming with MySQL

Basic HTML Syntax (continued) 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"> Model #:LEX 1382100 Compatibility: Optra 4049/3112/3116 Price: $189.99 Model #:LEX 1380520 Compatibility:Lexmark 4019/4028/4029 Price:$209.00 </body> </html> PHP Programming with MySQL

Basic HTML Syntax (continued) Figure 1-1 A simple HTML document in a Web browser PHP Programming with MySQL

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 PHP Programming with MySQL

Web Communication Protocols (continued) • 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 PHP Programming with MySQL

Web Communication Protocols (continued) • 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 PHP Programming with MySQL

Web Communication Protocols (continued) http://www.google.com/help/index.html Protocol Domain name Directory Filename Figure 1-4 Sample URL PHP Programming with MySQL

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 e-mail • America Online, CompuServe, and EarthLink PHP Programming with MySQL

Publishing Your Web Site (continued) • 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 • A domain name is a unique address used for identifying a computer, such as a Web server on the Internet PHP Programming with MySQL

Publishing Your Web Site(continued) • 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 tofind out the availability of a domain name and register it • Domain names are stored in a master database that is maintained by the InterNIC PHP Programming with MySQL

Publishing Your Web Site(continued) • 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 PHP Programming with MySQL

Publishing Your Web Site(continued) • File Transfer Protocol(FTP) • Is a TCP/IP protocol used for transferring files across the Internet • Transfers files between an FTPclient (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 PHP Programming with MySQL

Publishing Your Web Site(continued) • 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 Filezilla, Firefox, Internet Explorer • Allows you to use your browser to log on to an FTP server and upload your files PHP Programming with MySQL

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 PHP Programming with MySQL

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 PHP Programming with MySQL

XHTML Document Type Definitions (DTDs) (continued) • 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 PHP Programming with MySQL

XHTML Document Type Definitions (DTDs) (continued) • 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 PHP Programming with MySQL

XHTML Document Type Definitions (DTDs) (continued) Table 1-2 HTML elements that are deprecated in XHTML 1.0 PHP Programming with MySQL

XHTML Document Type Definitions (DTDs) (continued) • 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 PHP Programming with MySQL

XHTML Document Type Definitions (DTDs) (continued) • 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" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> • Always try to use the strict DTD PHP Programming with MySQL

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 PHP Programming with MySQL

Writing Well-Formed Documents (continued) • Empty elements must be closed • XHTML elements must be properly nested • Nesting refers to how elements are placed inside other elements PHP Programming with MySQL

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 PHP Programming with MySQL

Cascading Style Sheets (continued) • 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 PHP Programming with MySQL

Cascading Style Sheets (continued) • 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 PHP Programming with MySQL

Client/Server Architecture • Server (“back end”): • A database from which a client requests information • Fulfills a request for information by managing the request or serving the requested information to the client • Responsible for data storage and management • A system consisting of a client and a server is known as a two-tier system PHP Programming with MySQL

Client/Server Architecture (continued) • 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 PHP Programming with MySQL

Client/Server Architecture (continued) • 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 PHP Programming with MySQL

Client/Server Architecture (continued) Figure 1-16 The design of a three-tier client/server system PHP Programming with MySQL

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) PHP Programming with MySQL

JavaScript and Client-Side Scripting (continued) • 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 PHP Programming with MySQL

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) PHP Programming with MySQL

Server-Side Scripting and PHP (continued) • 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 PHP Programming with MySQL

Server-Side Scripting and PHP (continued) • 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 PHP Programming with MySQL

Appendix A Introduction to Web Development PHP Programming with MySQL