Ads 468x60px

Thursday, July 28, 2011

Web Development Environment

Web Development Environment
Many people are Web page "authors." Armed with a visual Web production tool such as Microsoft FrontPage, Macromedia Dreamweaver, Adobe GoLive!, and others, even a technical novice can throw together a Web site with decorated text and sparkling graphics to present all manner of personal statements on the Web. You may be one of these people, spanning the generations between toddlers and grandparents, to have one's own Web site or to have produced sites for others. It is no small trick to do so, but you are just dipping a toe into an ocean of opportunity.
Fewer people are Web site "developers." A smaller cadre possess the technical know-how and system-level sensibilities to produce sites that are truly useful, responsive, self sustaining, and intregal to the public lives they represent. More importantly, fewer people are able to create commercial-grade Web sites, those that are foundational to the operations and management of modern organizations. Here is where the action is and herein lie the know-how and skills to separate yourself from the crowded pack of Web page authors. You are soon to join these latter ranks of professional Web developers, possessing a toolkit to pursue the depths and breadths of Web technologies.

Web Page Authoring
Authoring Web pages is not a particularly difficult task now-a-days. Many standard deskop software packages come equipped with built-in features to convert word processing documents, spreadsheets, databases, and the like to coded documents that are ready for access across the Web. These and other authoring packages permit creation of Web pages with drag-and-drop ease. In most cases it is not even necessary to know or even to be aware of the special HTML (HyperText Markup Language) coding that takes place behind the scenes. It's all produced for you in documents that can be published on the Web for immediate access.
If you know the HTML language -- more recently XHTML (eXtensible HyperText Markup Language) -- then you can author your pages with a simple text editor, usually gaining a great deal more control over their structure and formatting than is possible with drag-and-drop methods. In addition, you have the ability to easily integrate HTML code, browser scripting languages, Java applets, multimedia plug-ins, and other processing features to bring a modicum of user interactively to your pages. Irrespective of the substance or sizzle of your pages, however, their purpose tends to be limited to presenting interesting or informative text and graphics for personal consumption. It is unlikely you can tackle the task of producing a commercial Web site or Web-based business system armed with HTML and a few plug-ins.

Web Development
Professional Web development goes well beyond the use of HTML markup codes and a few plug-ins and scripting techniques to make attractive and informative Web pages. It involves producing Web sites that have commercial or business value. It involves the use of special strategies, tools, and techniques to produce applications best characterized as Web-based, three-tier, client/server, information processing systems. These terms are considered in more detail below for understanding the broader-ranging purposes for which Web pages and Web sites are developed.

Information Processing Systems
Web technologies can be used not just to produce simple personal or promotional Web sites but are becoming important means to support the foundational business processes of modern organizations, that is, their underlying operational and management-support functions. The technical infrastructures to realize these purposes are roughly classified into three types of Web-based information processing systems termed intranets, internets, and extranets.
Intranets. Intranets are private, internal systems to help carry out the day-to-day information processing, management information, and work-flow activities of organizations. Web-based intranets service these standard business functions and in doing so impact basic organizational systems such as accounting and financial reporting systems, marketing and sales systems, purchasing and distribution systems, production systems, and human resource systems, among others. In time, Web-based intranets will likely become the primary technical means through which organizations function internally to carry out their business and work-flow processes.
Internets. Internets are public information systems. They include public sites that provide news, information, and entertainment; electronic commerce (e-commerce) sites to market and sell products and services; government sites to inform or service the general public; and educational sites to provide local and remote access to education and training. In all sectors of society public internets are providing goods, services, and information to the public through the World Wide Web (WWW) and its associated networks and facilities.
Extranets. Extranets are business-to-business (B2B) systems that manage electronic data interchange (EDI) between business enterprises. These systems facilitate the flow of information between organizations -- between a company and its suppliers and between the company and its distributors -- to help coordinate the sequence of purchasing, production, and distribution. Electronic data interchange helps eliminate the paper flow accompanying business transactions by using Web technologies to transfer electronic documents for processing between computers rather than between people. As Web-based systems, EDI applications eliminate the difficulties of transmitting information among different hardware and software platforms with inherently different information formats and with different protocols for exchanging information.
In short, the Web is becoming the primary technical means, the electronic highway if you will, for information production, collection, processing, and distribution in all types of organizations -- in commercial and financial enterprises, educational institutions, government agencies, health-care facilities, news and entertainment industries, and in most other formal organizations both large and small. It is the pervasive technology for developing information processing systems in all sectors of society.
The term "Web-based" implies that information processing systems rely on the technology of the Internet, particularly on that portion known as the World Wide Web (WWW), for implementation. That is, Web-based systems operate within a technical framework with the following characteristics.
First, systems operate across public, rather than private, data networks. They communicate over the Internet, the world-wide interconnected networks of computers that are publically accessible. This means that Web-based information systems can literally span the globe with processing activities shared among components located anywhere on Earth and beyond where Web service is available.
Second, these communications networks are based on open and public technical standards such as Ethernet architectures, TCP/IP transmission protocols, and HTTP (HyperText Transport Protocol), FTP (File Transfer Protocol), SMTP (Simple Mail Transfer Protocol), and other common application protocols. These are not private or proprietary standards but are fundamentally open and free to public use.
Third, Web-based systems use common, often-times free, software for development and delivery. Even the most complex systems can be coded with nothing more than a standard text editor and placed into production through common Web server software. This software is usually built into the server computer's operating system or can often be downloaded for free. Also, interaction with Web-based systems takes place through standard Web browsers rather than specially configured hardware and software. Of course, as Web-based systems grow and become more crucial to operations they require additional components to increase capacity, speed, and security. However, most hardware and software components are off-the-shelf varieties rather than special-made.
Thus, common, non-specialized, non-proprietary hardware and software systems provide the technical environment for developing information processing systems and for operating and managing information processing activities.

Three-tier, Client/Server Architecture
The term "client/server" pertains to the use of server-based networks to manage resource sharing and to distribute processing tasks among hardware and software components. Within Web-based client/server networks the distribution of processing tasks occurs in three tiers that correspond to the three primary hardware/software components of the system. These tiers are shown in Figure 1.1.

Figure 1-1. Hardware and software layers of a three-tier information processing system.
In Tier 1 the desktop PC client handles the user interface activities of the system; in Tier 2 the Web server handles the primary processing functions of the system; and in Tier 3 the database server, and in certain cases the media server, handles information storage and retrieval functions required by the system.
In turn, each of the three hardware components host corresponding software. The client software is a standard Web browser such as Microsoft Internet Explorer. The Web server runs a network operating system such as Windows Server 2003 with component services such as Internet Information Services (IIS) hosting World Wide Web, FTP, SMTP mail, and other Internet services. The database server runs a database management system such as SQL Server, Oracle, Access, or other popular package. In sum, separate system components perform separate processing tasks that are integrated through the Web into a complete information processing system.
Consider, for instance, your visit to an e-commerce Web site such as or Your Web browser is your interface with the site. In response to various "input" requests you submit as you navigate the items for sale, various "output" pages are produced. Your requests are entered into the system through Web links and form submissions; system responses produce HTML pages delivered back to your browser for display on the screen. The browser performs the input and output activities needed to interface with the site.
Behind the scenes special information processing tasks are taking place on the Web server. When you request a book search, for example, programs are run to search databases to extract matching books and to format the output for delivery to your browser. When you view your shopping cart other routines retrieve your choices and summize your purchases. When you check out special programs are run to link into the credit checking and banking systems so that appropriate accounts are debited and credited. Myriad processing tasks associated with your browsing and purchasing experience take place on Web servers, hidden from your view and scattered geographically, but crucial to your shopping experience and to formalizing the business transactions that result.
Most of the information that is captured and generated by your shopping visit is kept in large databases hosted on separate database servers. All of the book information that you see on screen is extracted from database tables. Your purchase selections are stored in database tables. Virtually every piece of information regarding the products you view and your purchase transactions are maintained in massive databases within the e-commerce system itself or in associated databases central to the accounting, purchasing, and distribution systems that surround it.
In even the smallest Web-based commercial systems this same functionality is present. The Web browser provides the user interface to the system, special processing pages handle the business transactions, and one or more databases maintain information flowing through the system. The point is that in Web-based systems of any size the three primary tiers of functionality exist. From the standpoint of the Web developer, then, the task is to build these three separate components -- the user interface, the business processing routines, and the database maintenance components -- and to integrate then into a fully functioning information processing system.


Post a Comment