Web based School

Chapter 1

Introducing Visual InterDev and the World Wide Web

Visual InterDev, the long-awaited Web application development tool from Microsoft, is finally here. Many developers are applauding its features and the application development needs that it addresses. Developers now have a tool similar to other application development tools like Visual Basic and Visual C++ that they can use to create their Web applications. No more downloading the latest beta copy of a single-focused tool from the Web. You now have a tool that integrates many of the popular components and technologies.

During the first Chapter, the context for Visual InterDev will be set, and you'll be introduce to some of the latest developments concerning the Internet and the WWW. You will learn about the importance of the Internet. You also will learn about the rising number of intranets, or private internets, that are growing within many companies. You will see how the WWW has become ubiquitous and the implications that it has for individuals and businesses. In discussing the WWW, you will discover the differences between static and dynamic web pages and what you should focus on for the future. You will then be introduced to the reasons for having an application development tool for the Web. Finally, you will get a glimpse of Visual InterDev.

NOTE: In this guide, the term Web and WWW are used synonymously to refer to the commercial collection of Web servers located on the World Wide Web. The term web is used to refer to pages and sites that are individual in nature. Most of the time, web refers to pages that you're developing to build your site.

The Importance of the Internet

You obviously realize the importance of the Internet or you wouldn't be reading this guide. The Internet and the World Wide Web are everywhere. You can't read the newspaper or watch television without seeing some kind of reference to the Internet. "Cyberspace" and the "Information Superhighway" have become common vocabulary for a whole new audience. Virtually every television commercial and print ad contains a reference like the following:

"For more information, visit us at our Web site at www.whatever.com."

The Internet has come a long way since the old ARPANET Chapters. Originally designed for research use by the Department of Defense, the Internet has become a haven for millions of people who have experienced the value of communicating with people around the world. Internet users have instant access to a plethora of knowledge supported by this network of networks.

Most people point to 1991 as the beginning of the Internet explosion. In the late 1980s, the academic community began to see the Internet as a valuable tool. Professors and students at universities around the world began using the Internet as a way to gain valuable research and knowledge about myriad subjects. Services such as electronic mail (e-mail), file transfer capability (ftp), and newsgroup discussions all contributed to the growth of the Internet audience. Then, in 1991, the National Science Foundation (NSF), which was the major funding group for the Internet, dropped most of its financial support and allowed commercial traffic onto the Internet. The door was now open for all types of individuals and businesses to take advantage of this vital communication network.

We are truly living in the Information Age, and the Internet has become the primary means for expanding our horizons. The Internet has opened up any number of possibilities for applications by providing a ready-made network for businesses to use. Growth in the Internet has also forced us to rethink the way we approach life. A student in California can communicate with his parents in Florida via e-mail instead of building up a hefty, long distance telephone bill. In fact, now most families can conduct conversations over the Internet, thereby skirting the phone companies.

With the growth of the WWW, businesses have been scrambling to gain a presence on the Internet. In 1995, corporate spending on Internet/intranet systems was $12 billion. This figure is expected to grow to $208 billion by the year 2000. Developers will play a huge role in helping organizations and businesses understand the importance of using the Internet from an application and communication standpoint.

The Rise in Intranets

Many companies are realizing the benefits of the Internet from within their companies. These organizations are creating intranets, which are private, or internal, internets. These intranets have been established initially as an internal communication tool. Employees can send e-mail to other employees within the company. Intranets enable private and sensitive corporate information to be distributed and shared within the organization. This new medium of communication has become a very cost-effective solution, especially for geographically dispersed businesses that have employees all over the world. The time to communicate new policies, procedures, and information is immediately reduced along with postage and paper costs.

An intranet also can be used for software distribution and for providing access to vital applications. Companies are now starting to put applications like survey forms and employee benefit registration forms on their intranets to simplify basic processes. Businesses also are starting to consider replacing or enhancing their mission-critical applications (like accounting, sales order entry, oil and gas trading, and so on) with applications that are secured within an intranet. Intranets are usually protected and secured by means of a firewall that prevents outside intruders from accessing the internal network. To the user, there is no difference between accessing the Internet and the company's intranet. Figure 1.1 depicts a typical configuration for an intranet.

Figure 1.1.

A high level view of an intranet.

Sun Microsystems is a perfect example of how a company can save real money in terms of printing, processing, and mailing costs through the use of an intranet. Sun has used the Internet to communicate basic corporate information, such as organization charts and geographic office locations. Employees can access monthly updates from their CEO Scott McNealy which are presented in audio and video formats. Sun also provides information about its products by providing an online product catalog and updates on new products. Employee information regarding training, travel, and human resource policies is placed on the intranet. Sun even provides an "Applications Chest" that gives employees access to a variety of tools that enhance their productivity.

Internet performance has become a huge topic of conversation. Some individuals have even discussed totally redesigning the Internet infrastructure to support the growing number of users. Without entering this debate, I would like to point out that intranets provide a way to use the Internet while taking more control over performance of your applications. With an intranet, a company can use the Internet architecture model while providing the internal infrastructure to guarantee response time and security.

Intranet applications also are cost effective from an administration and deployment standpoint. The browser serves as the universal client for all desktops. The server makes the desktop come alive by providing information and database access. Deployment and administration costs are reduced, because you don't have to reinstall an updated application on everyone's desktops as you do when creating proprietary client-server applications. Electronic commerce is going to drastically grow in the next few years and with it will come a continued rise in the use of intranets.

This section has described intranets as being internal to an organization or business. Private intranets that focus on providing a reliable and secure infrastructure for groups of businesses also are emerging. Technology companies are beginning to prepare for this occurrence. Microsoft formed an alliance with British Telecommunications and MCI to provide private data networks for global companies and their customers.

Private intranets offer the same reliability, security, and guaranteed response time that a company's internal intranet provides. The difference between them is that a company's reach extends beyond the internal organization to external entities. The use of private intranets will continue to rise as application requirements exceed the current capabilities of the Internet infrastructure.

The Ubiquitous Web

The second explosion that propelled the Internet into national prominence was the creation of the World Wide Web. The Web has many origins, but most people point to the time period between 1989-1991 when the Conseil European pour la Recherche Nucleaire (CERN) European Laboratory for Particle Physics in Geneva, Switzerland, developed its first specifications. Tim Berners-Lee, a researcher for CERN, developed the basic concepts of sharing information through the use of a consistent, universal interface. Mark Andreessen is credited with developing the first browser (Mosaic) for the Web in 1993. The use of a browser to view the Internet turned attention away from the information stored on the server, focusing more on the user experience through the client machine. The browser provided a graphical, point-and-click interface for viewing Web content that made the Internet easier to access.

The Web is the primary service responsible for bringing the Internet into the homes of millions. The Web is the most popular and useable service. The hypertext links to a plethora of information allow the user to experience a "web" of knowledge. The user can choose the learning path instead of following a sequential or linear pattern.

The most recent numbers estimate that more than 45 million people have visited the Web at least once. When sports figures, music celebrities, and news anchors are touting the Web, you know it has become ubiquitous. The Web provides an alternate delivery channel for all types of information as well as graphically robust applications. Major software vendors are totally revamping their products to make them Internet-enabled. Banks are having to rethink their strategy of targeting and servicing their customers by providing online banking. Businesses are establishing a presence on the Web to offer products and services electronically. The Web is everywhere, and we must learn how to properly and constructively use its capabilities.

The first wave of Web development involved information publishing. Rudimentary tools were provided to convert documents created with common word processors to the HTML format of the Web. HTML editors also have provided a way to create original documents as well as Web pages and deploy them on the Web. As stated, the Internet and the Web have saved a lot of money for companies in terms of printing, processing, and mailing costs. The Web has extended the notion of textual documentation to provide graphical information as well. Graphics, 3D images, audio, and video can truly enhance the user's experience on the Web. Companies like Macromedia and RealAudio have contributed to the multimedia experience by providing enhanced and animated graphics and audio capability. The ESPNET SportsZone is one of the most popular sites on the Web largely due to the way the site employs multimedia. You can download ESPN commercials both in audio and video format as well as listen to press conferences and other sporting events. This site does owe some credit to the popularity of ESPN, but the people would not be visiting the site if it didn't provide a rich and rewarding experience.

The second wave of Web development has been the creation of functional applications. These applications extend the simple registration forms commonly seen on Web sites to become true interactive applications that include database accessibility. These applications can be classified as just another phase of client-server.

In taking a look at the architecture of the Web, many of the principles have been carried over from client-server architectures. Figure 1.2 illustrates a typical client-server architecture.

Figure 1.2.

A typical client-server architecture.

Client-server is a style of computing where the client machine makes a request of a server machine. The request is usually a request for information, as in a database request, or for processing, such as updating a database or running a batch process. The client machine makes the request, and the server machine fulfills this request. The benefit of client-server systems is that they take advantage of the strengths of each machine or platform. In a typical scenario, the client handles some application logic and the presentation to the user while the server provides the back-end processing and database functions.

In a typical Web application, the browser serves as the universal client that sends a request for a web page, interprets the HTML document, and displays it to the user. The web server receives the request through the HyperText Transport Protocol (HTTP) and returns the required information in HTML format that the client can understand. Similar to client-server, you can distribute the application processing and database management portions to varying degrees between the client and the server machine. Figure 1.3 depicts a typical Web-based architecture.

Figure 1.3.

A typical Web-based architecture.

The main benefit to Web-based applications over client-server is found in the deployment. In a Web-based scenario, you don't have to deploy a new executable on each person's desktop with each new application feature or update. The browser serves as the universal client, providing access to the most current information on the server. Version control, software distribution, and systems management costs are significantly reduced for Web-based applications.

A more in-depth discussion concerning how the web client and server interact is warranted here. Historically, Web applications have been based on HTML and common gateway interface (CGI) programs on the server. The Web browser interprets the HTML tags and appropriately formats the page for the user. A web page can be a combination of formatted text, images and graphics, audio, and video. HTML also allows for the creation of basic forms that contain text fields, radio buttons, checkboxes, push buttons, and listboxes. These objects are discussed in more detail on Chapter 12, "Using Basic and Advanced HTML Form Controls."

CGI programs have typically been used for processing requests on the server and distributing information to the client machine. CGI programs, or scripts, are executable files that can be built using languages such as UNIX shell script, Perl, C, and so on. As information is updated on your database, the CGI script can handle accessing the data and passing the information back down to the client browser. The advantage is that you don't have to write new HTML code for every new document or database update. The CGI server program provides a reusable component that saves development time.

I mentioned the HTTP protocol earlier in this chapter. HTTP is the protocol that allows the browser to connect to a web server. HTTP is a stateless protocol; that is, the client and server don't maintain a persistent connection. The client makes a connection to the server and sends a request. The server receives the request, processes it, then terminates the connection. This process is repeated many times during a user session. This kind of communication would be like having a telephone conversation with a friend where you would say something, hang up the telephone, then dial again to say something else. This dialogue is very tedious. Interactive applications must have some way to maintain state with the user machine in order to provide for the needs of applications like sales order processing.

Microsoft and Netscape have led the charge to develop an effective server process that supports a more interactive state with the client machine. The creation of application programming interfaces, or APIs, has opened up all kinds of possibilities over the traditional use of CGI programs. There are several specific benefits to using APIs. First, APIs are more efficient than CGI programs. A CGI program opens up a process in memory for each client request. APIs execute processes in the same memory address space, eliminating the overhead of separate executing processes on one machine. By using this model, APIs use less memory for executing a process. Also, initialization with the client machine is performed once for all requests. Another benefit of APIs is their ability to maintain state. API programs permit a persistent connection between the client and server, which can be a huge benefit when developing an application with moderate to intensive database connectivity. Also, separate requests can share information about the client, because the programs remain resident in memory.

The main disadvantage to APIs is that they're proprietary in nature. Whereas CGI programs are server-independent, APIs are confined to their respective web server platforms. Table 1.1 presents the most common APIs and their supported server platforms.

Table 1.1. The most popular APIs, their respective vendors, and supported server platforms.

API	Vendor	Server Platform Supported
ISAPI	Microsoft	Microsoft Internet Information Server, Process Software Purveyor WebServer
NSAPI	Netscape	Netscape Commerce/Communication Server
WSAPI	O'Reilly & Associates	O'Reilly & Associates WebSite

To summarize, the Web has become popular for a variety of reasons. The Web provides graphically rich content on a variety of topics to many users. The Web also supports transaction-based services that enable businesses and consumers to come together in an electronic market. Examples include ordering guides, making airline reservations, and trading stocks. Learning is also significantly enhanced by having access to all kinds of documents, white papers, and training materials. Name the subject, and you can become an expert on it in no time at all by accessing the Web.

The Difference Between Static and Dynamic Web Pages

Web-based applications have made the transition from solely publishing information to creating an interactive session with the user. Static web pages represent those pages that provide information that is nicely formatted in standard HTML. For example, a person might be able to request an employee benefit handguide to become familiar with the latest updates in benefits. Static pages are nice, but users want something more.

Dynamic web pages are those pages that provide true user interaction. In this model, users interact through the use of server-side programs that provide for an enhanced experience. Instead of just reading about the latest human resource benefits, employees can register and update their benefits. Dynamic web pages support the building of true interactive applications. Once you have read the published flight schedules, you can make airline reservations electronically over the Internet. Stock brokerage houses can publish the hottest stock tips and then enable you to capitalize on the investment through online stock trading. Dynamic web pages provide a world of new possibilities over static pages.

I briefly discussed the use of CGI and API programs in providing a gateway between your client and server machine in a Web-based application. Here, I will focus on the ability to use client- and server-side scripts to create dynamic HTML web pages.

Client-side script is usually associated with objects on the HTML page. These objects could be standard HTML controls or ActiveX controls. Client-side script is usually included to make up for the limited functionality of HTML. The script is included in the HTML page when it is downloaded from the server to the client machine. The script code executes on the client machine in response to user interaction and program events. By keeping the script in the HTML page on the server, a developer only has to make changes to centralized code located on the server. The browser downloads the revised web page simplifying the software distribution process. The goal in this model is to keep the code resident on the server leaving little or no code on the client machine. Some examples for using client-side script include user interface functions, entry verification, and standard programming functions.

Two of the most popular scripting languages are Netscape's JavaScript and Microsoft's VBScript. Visual InterDev supports both of these scripting engines, although Microsoft has implemented its own version of Netscape's JavaScript called JScript. There are no significant differences between the JScript and JavaScript implementation.

Another way to create a dynamic experience is through the use of ActiveX controls and Java applets. Visual InterDev includes and supports the use of both ActiveX controls and Java applets within your application. These controls provide many additional functions from multimedia to database connectivity. Both JavaScript and VBScript are used to interact with these controls extending the reach of the interface. Similar to the use of Visual Basic code with Visual Basic controls, VBScript and JavaScript serve as the glue between the browser and the particular control. The process is essentially the same as using a traditional client-server tool like Visual Basic. You add a control to your page, setting its methods and properties. Once you have established the basic properties, you add scripting code to handle the application logic. Visual InterDev incorporates a visual tool for creating client-side script for your ActiveX controls. The Script Wizard, first included in the ActiveX Control Pad from Microsoft, provides a visual interface that builds both VBScript and JavaScript.

Visual InterDev also supports the use of Active Server Pages. Active Server Pages are a new feature included with Internet Information Server 3.0; they provide a framework for creating dynamic Web pages.

Active Server Pages are based on the ActiveX Scripting engine and enable you to include server-side executable script directly into an HTML document. You can create Active Server Pages using any of the popular scripting languages, including VBScript, JavaScript, Perl, and so on. Figure 1.4 illustrates how an Active Server Page interacts with a client machine.

Figure 1.4.

This diagram shows how Active Server Pages interact in a Web-based application.

You will notice from the diagram that the web clients communicate with the web server through the HTTP protocol. The web server can be on the Internet or within an intranet. The web server is comprised of Internet Information Server 3.0, which includes the ActiveX Server Scripting engine. The diagram shows the Active Server pages, or .asp files, where the server-side script resides. These files are simply HTML pages that contain scripting code. This scripting code extends basic HTML and provides additional functionality for your application.

Visual InterDev enables you to create Active Server Pages. Some of the visual tools within Visual InterDev generate much of the server-side script for you. You have the ability to modify this code as well as create your own server-side script. You will get your chance to build Active Server Pages on Chapter 11, "Extending Your Application Through Active Server Script."

The Need for a New Kind of Tool

There are many extensive and powerful technologies for creating Web applications, but most tools only focus on a single, specific need. Other tools are being developed to address a few needs. Developers have been dreaming of the Chapter when they can use a comprehensive, integrated development environment to build their applications. Why, you ask, do you need an integrated tool? Take a walk through a typical Web development effort and look at the many different types of tools that you can use to build a Web-based application.

First you need an HTML editor. Many people have created a new function for an old product and made Notepad the HTML editor of choice. Table 1.2 outlines some of the more robust and popular products on the market.

Table 1.2. Popular HTML editors.

HTML Editor	Vendor
Hot Dog Pro	Sausage Software
HoTMetaL Pro	SoftQuad
NaviPress	Navisoft
FrontPage	Microsoft

Microsoft also has created add-in products for its Office suite of products that enable HTML conversion. For example, a user who is familiar with Microsoft Word can use the Internet Assistant for Word to convert a document to HTML format for display in a browser.

NOTE: The Office 97 suite of applications supports the ability to save files for HTML formatting for display on the Web.

Choosing an HTML editor is only the beginning. To build an application, you must consider the server-side products as well. You have two basic choices, as previously mentioned: CGI or APIs. If you choose to use CGI, you will need to find a programming environment based on the language you select. The possible languages include Perl and UNIX shell scripts, Visual Basic, C, and C++. If you choose an API, you need to select the appropriate API implementation for your application platform's web server. Refer to Table 1.1 for a listing of APIs and their supported web server platforms. API server programs are implemented as dynamic link libraries (DLLs) and built using either C or C++. Again, you will need to select the appropriate programming environment to support the selected language.

Java also can be used on the server to provide additional functionality for your Web-based application. Sun Microsystems built Java as an independent programming language. It can be implemented as an application program or as a Java applet. A Java application can interact with system resources and make calls to external programs. A Java applet is found embedded within a web page and cannot interact with system resources. Regardless of your Java implementation, an environment will be needed to support your Java development. Microsoft's Visual J++ and Symantec's Visual Café are some of the more popular tools for Java development.

You will invariably need to select a scripting language to support the functionality of your application. Whether it is VBScript or JavaScript, you will need an editor. Notepad, Visual Basic, and the ActiveX Control Pad from Microsoft all can support your VBScript needs to varying degrees. Netscape Navigator Gold and Notepad support JavaScript development.

If you're wondering about connecting your application to a database, many options exist for database connectivity, depending on how you want to implement your application. If you're building a Java-based application, you will select a tool that supports Java Database Connectivity, or JDBC. Most of the popular Java tools also support JDBC. Microsoft and Netscape also provide environments and tools for database connectivity based on their API specification.

The point in this example is that you could spend a lot of time and effort using a number of tools to implement a robust, Web-based application. Compatibility between the tools becomes a debugging nightmare. Also, you spend a lot of time switching between the development environments, thereby diminishing your productivity. Due to these limitations, Microsoft created Visual InterDev to address the many needs for toChapter's Web-based application developer.

Presenting Visual InterDev

The emphasis in creating Visual InterDev was to provide a tool with a comprehensive, integrated development environment. Visual InterDev's creators wanted to provide a tool that enabled developers to utilize many technologies to create and deploy dynamic, Web-based applications. Microsoft also wanted to emphasize a visual tool. Many products have been created that enable you to code HTML or connect to a database; however, these tools typically haven't focused on the ease of use for the developer.

Developer productivity was a major design goal for Microsoft, and they have accomplished it by providing Visual InterDev with many wizards and visual tools, as well as database development features. Powerful database integration and connectivity were clearly of paramount importance for its design. Visual InterDev even supports developers in deploying their sites once they have been built by integrating comprehensive tools to create and maintain a web site into Visual InterDev.

Integrated Development Environment

Visual InterDev provides a robust, integrated development environment to address the many capabilities of the Web. You can integrate various technologies, like ActiveX controls and Active Server Components, to create a powerful application. The integrated development environment enables you to use scripting languages like VBScript and JavaScript to create dynamic applications and Web pages. You can work on simultaneous projects of different types all from within Visual InterDev's Developer Studio interface. In addition to Visual InterDev projects, you also can develop Visual C++ and Visual J++ projects.

Visual InterDev Features

Now that you have been introduced to the features and benefits of the integrated development environment, it's time for a brief look at some of the specific features of Visual InterDev. This discussion sets the context for Chapter 2, in which you will get to meet Visual InterDev up close and personal.

Visual InterDev includes a wide range of visual tools to augment an application developer's productivity. HTML editing is significantly enhanced through the use of the HTML Layout Editor and a version of the FrontPage HTML editor. The HTML Layout Editor, introduced with the ActiveX Control Pad from Microsoft, enables you to precisely place your ActiveX controls onto your web page. It also enables you to control the x and y coordinates to ensure that the ActiveX controls are displayed in the proper manner. By using this tool, you're able to take more control of your user interface, and can ensure that the interface you build is an effective one.

Visual InterDev also provides WYSIWYG editing through its own FrontPage 97 HTML editor. FrontPage enables you to visually author your HTML page. Content authors can use FrontPage 97 to create files that are completely compatible with Visual InterDev's version of the FrontPage Editor. Visual InterDev also provides site management tools that are very similar to those tools provided in FrontPage 97.

The Script Wizard is another visual tool that greatly enhances a developer's productivity. The Script Wizard enables you to associate specific actions with associated ActiveX control events. By linking these events and actions, the Script Wizard generates all of the necessary script language for you. Once the language is generated, you have the ability to modify and add to the code. This process can save you considerable development time by generating the routine script and enabling you to focus on the more advanced code for your application.

Visual InterDev also includes two tools for spicing up your web pages. These tools focus on multimedia creation and management. The Microsoft Image Composer and Microsoft Music Producer enable you to create graphical images, music, and sounds for your web site. You can use the Microsoft Image Composer to create engaging images for your web pages. The Image Composer supports the Adobe Photoshop file format as well as GIF and JPG formats. The Image Composer is simple to use, and you don't have to be a graphic artist to master it. The Music Producer enables you to create music and sound effects for your web site. You pick from over 100 pre-defined styles of music and can modify the arrangement of instruments as well as the tempo.

Again, the goal of both of these products is to provide a rich and rewarding experience for the user. The Media Manager enables you to manage all of your multimedia files through the use of specialized folders. By using Media Manager, you can properly organize your images, sounds, video clips, and other multimedia files.

Now consider some of the key features for building robust server applications. Visual InterDev enables you to create dynamic web pages through the use of Active Server Pages. The concept of Active Server Pages was touched on earlier in the Chapter. As a refresher, Active Server Pages are HTML pages that contain server-side script. The script code can be either VBScript, JavaScript, or some other scripting language. The Active Server Page, or .asp file, resides on the server machine and executes before being downloaded to the browser.

Active Server Components are a significant part of building distributed and powerful applications. Active Server Components are programs, DLLs, or executables (EXEs), that are built using the Component Object Model (COM) specification. Visual Basic, Visual C++, and Visual J++ all support the development of COM-based components. These programs can be called from Active Server Pages to provide robust application processing on the server machine.

For example, you might want to build an Active Server Component that uses the strength of the C++ language to perform financial analysis and return the results to the Web browser. You also can distribute the application processing load through the use of Distributed COM (DCOM). Active Server Components provide a method for building high transaction processing capability into your application. Visual InterDev provides an environment that is conducive to incorporating these components into your applications.

Database Integration

Visual InterDev provides some very robust database tools. The Visual Data Tools included with Visual InterDev are easy to use and significantly reduce the time and effort for adding database capability into your application. Some of the features include the following:

Data View. Visual InterDev project window that enables you to view all of your database objects including tables, views, stored procedures, and triggers.

Query Designer A tool that enables you to visually build your SQL database queries and test the results.

Database Designer A tool that enables you to design, create, and maintain your SQL database.

Stored Procedure/Trigger Editor A tool for editing stored procedures and triggers for Microsoft SQL Server 6.x and Oracle 7.x.

The Query Designer and the Database Designer employ a user interface similar to Microsoft Access that's very easy to use. You can drag and drop objects into the workspace and automatically build your SQL queries. You also can use the Database Designer to populate the database and modify existing data.

Other database features include the following:

ActiveX Data Objects. An object-based approach to accessing a database over the Web that uses ActiveX Scripting.

Database Design Time Controls.Controls geared toward the automatic creation of database connectivity and generation of Active Server scripting.

Database Wizards. Wizards that guide you through the creation of an HTML, data-bound form

Database connectivity and integration is one of the best features of Visual InterDev. You will get a chance to use these features and tools beginning with Chapter 8.

Summary

ToChapter you began a glorious journey to the land of Web-based application development. You started the Chapter with a discussion of why the Internet is important and were introduced to the significance of learning how to properly use this communication vehicle from a business perspective. You then moved on to intranets and learned about the rise in these vital private networks. You learned how businesses use intranets for communication, software distribution, and applications now and in the future. You then read about the most popular service of the Internet: the World Wide Web. After reading a brief history of the Web, you learned about the different waves of Web development.

You also learned about the similarities and differences between Web-based applications and client-server applications. You found out about the difference between CGI and API programming. You received an overview of the differences between static and dynamic Web pages, then learned how client- and server-side script could be used to provide an interactive experience for the user.

Throughout the lesson, you got a feel for the need for a tool like Visual InterDev. You were walked through an example that showed the range of tools that could be used when building a Web-based application. At the end of the Chapter, you were presented Visual InterDev for your approval. Finally, you got a taste of the features and tools that are included in the tool. What did you think? I bet that you can't wait until tomorrow to meet Visual InterDev up close and personal.

Q&A

Q What's the difference between client- and server-side script?

A Client-side script is included within the HTML page and executes on the client machine in response to events and user interaction. An example includes validating data entered into a field before the page is sent to the server. Server-side script is script that resides on the server machine and is processed on the server before a page is sent back to the client machine. Server-side script enables you to provide application processing that can call other application programs, such as an Active Server Component.

Q Does Visual InterDev support the development of scripts?

A Yes. In fact, Visual InterDev generates much of the scripting for you.

Q What databases does Visual InterDev support?

A Visual InterDev provides connectivity to any ODBC-compliant database including Microsoft SQL Server, Oracle, Sybase, Microsoft Access, Microsoft FoxPro, and IBM DB/2.

Workshop

Make sure you have installed Visual InterDev. Tomorrow, you will be taking an in-depth look at the tool and its development environment. It's important that you have the tool installed so you can follow along with the exploration of its features.

Quiz

1. What is an intranet?

2. What are the two waves or phases of Web development?

3. What are the two most popular scripting languages that help to create dynamic web pages?

4. Name two of the Visual Data Tools.

Quiz Answers

1. An intranet is a private, or internal network, that provides access to the Internet but is secured from external access through the use of a firewall. Intranets are used as an internal communication tool and as a medium to distribute software and provide access to internal applications.

2. The first wave of Web development was the publishing of information. The second wave of Web development has been application development.

3. VBScript and JavaScript.

4. Possible answers include:

Data View
Query Designer
Database Designer
Stored Procedure Trigger Editor