Windows NT Internet and Intranet Development

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Microsoft Internet Explorer 3.0


Internet Explorer is Microsoft's flagship Internet application designed to browse information on the Internet. In addition to supporting state-of-the-art Web technologies such as ActiveX, VBScript, JavaScript, Java, and Cascading Style Sheets, Internet Explorer includes an Internet mail-reading application as well as an Internet news-reading application. See Chapter 3, "Microsoft Internet Mail," and Chapter 4, "Microsoft Internet News," to learn about Internet mail- and news-reading features of Internet Explorer.


URL: Visit the Internet Explorer home page for the most up-to-date information about Internet Explorer.

http://www.microsoft.com/ie/

Internet Explorer and Netscape Navigator Compatibility Issues

You will notice that no chapter in this book is devoted to Netscape Navigator. However, it is important to briefly discuss Internet Explorer and Netscape Navigator compatibility issues before proceeding. Although Netscape Navigator-specific coverage is not included in this book, material presented in upcoming chapters applies to both Internet Explorer and Netscape Navigator. Because Internet Explorer includes additional features such as ActiveX controls, ActiveX scripting, and Cascading Style Sheets, Netscape Navigator 3.0 users must install special plug-ins to browse and experience ActiveX-enhanced Web pages. Visit the following Web page for the most up-to-date information about Netscape Navigator.


URL: Visit the Netscape home page for the most up-to-date information about Netscape.

http://home.netscape.com/

Visit the following Web page to learn how Netscape Navigator users can use the ScriptActive plug-in to browse ActiveX-enhanced Web pages.


URL: Visit the NCompass Labs home page for the most up-to-date information about Netscape Navigator.

http://www.ncompasslabs.com/

At the time of this writing, Internet Explorer is a superset of Netscape Navigator, and thus includes all its functionality, features, and more. Because Internet Explorer plays such a large role in Microsoft's Internet strategy, Microsoft will most likely do everything in its power to maintain the lead--at least as far as the Windows and Macintosh versions of Internet Explorer are concerned. Given this and the fact that Internet Explorer is distributed free of charge, you might want to standardize on Internet Explorer to avoid potential Web-browser compatibility issues-- especially if your intranet consists of Windows- and Macintosh-based personal computers.

Downloading and Installing Internet Explorer

Internet Explorer can be downloaded from the previously mentioned Internet Explorer Web site. After you download the Internet Explorer distribution file, copy it to a temporary directory and execute it to begin installing Internet Explorer.


Tip: Download and install the full version of Internet Explorer to experience all the state-of-the-art ActiveX technologies in addition to Internet mail and news support.



Note: Close all nonessential applications before installing Internet Explorer. Internet Explorer might need to replace shared files in use by other applications. Also, be prepared to reboot your computer if necessary after Internet Explorer is installed.

Installing Optional Components

If you downloaded the full version of Internet Explorer, you will be presented with the Microsoft Internet Explorer Setup dialog box (shown in Figure 2.1) when you install Internet Explorer. This dialog box gives you the option of selecting various Internet Explorer components to install. I recommend that you select the Yes button to invoke the Optional Components dialog box (shown in Figure 2.2). If you select No, you will not be able to individually select various Internet Explorer components to install.

Figure 2.1. Microsoft Internet Explorer Setup dialog box.

Figure 2.2. The Internet Explorer Optional Components dialog box.

The Optional Components dialog box is used to select various Internet Explorer components to install. Make sure all components are selected and click the OK button. Select to install the ActiveMovie component if you want to be able to view multimedia files embedded in Web pages without setting up helper applications. Select to install the HTML Layout control so that you can view Web pages created using the HTML layout capabilities of the ActiveX Control Pad. These layout capabilities can be used to develop richly formatted Web pages.

Reboot Your Computer

Certain components that you selected to install in the Optional Components dialog box require you to reboot your computer before they take effect. If this is the case, you will be presented with the Setup dialog box (shown in Figure 2.3).

Figure 2.3. Microsoft Internet Explorer Setup dialog box. Choose to restart your computer.

Exploring Internet Explorer

The next few sections explore some of the features of Internet Explorer, outlining how they can be used in Internet and intranet environments to publish information.

Security

Microsoft Internet Explorer implements ActiveX control security using Authenticode security certificates. When you purchase a shrink-wrapped software application, you have a certain degree of confidence that the application has not been tampered with by a third party provided the seal is not broken. Prior to Authenticode security certificates, it was hard for users to detect third-party tampering of applications downloaded via the Internet. To make matters worse, users had no way of verifying who actually developed the software application. If an ActiveX control is digitally signed by the developer, the security certificate of the ActiveX control is displayed before Internet Explorer executes an ActiveX control (as shown in Figure 2.4). As you can see in Figure 2.4, the Authenticode security certificate displays information about the software developer of the ActiveX control and verifies that the ActiveX control has not been tampered with by a third party. Based on information in the certificate, the user can select to run the ActiveX control.

Figure 2.4. Authenticode Security Technology dialog box.

Users can also modify Internet Explorer security settings by selecting View|Options from the menu bar and selecting the Security tab. If an ActiveX control is not digitally signed, Internet Explorer confirms your wish to execute the unsigned ActiveX control provided Internet Explorer security is not set to High. Users should exercise caution before allowing Internet Explorer to execute unsigned ActiveX controls. It's best to not execute unsigned ActiveX controls found in Web pages of organizations that you do not trust.

Active Documents

Internet Explorer supports Active documents. Active documents are an extension of OLE across the Internet. Think of Active documents as files of applications that can be viewed and manipulated inside Internet Explorer. Notice how a URL is given to a Microsoft Word document in Figure 2.5.

Provided the user has installed either the Microsoft Word editor or the Microsoft Word Viewer, he will be able to view and manipulate the Word document inside Internet Explorer when he selects the URL that points to the Word document (see Figure 2.6). Notice how Microsoft Word toolbars are visible inside Internet Explorer. Active Documents technology is very powerful, and is especially useful in an intranet environment because it allows users to browse a document using the environment that was used to create the document. Imagine how much better it is to browse a live Excel spreadsheet, where the user can make changes to data and observe the results in real time as opposed to looking at a static HTML representation of an Excel spreadsheet.

Figure 2.5. A URL to a Microsoft Word document in a Web page.

Figure 2.6. Browsing a Microsoft Word document inside Internet Explorer with the aid of Active Documents technology.

ActiveX Controls and ActiveX Scripting

Internet Explorer supports ActiveX controls and ActiveX scripting (VBScript and JavaScript). These technologies can be used together to create interactive and multimedia-rich Web presentations. See Figure 2.7 for an ActiveX multimedia-rich presentation. The Web page in Figure 2.7 uses ActiveX to demonstrate how to make espresso over a 28.8 modem link via streaming audio and video. Try the URL of the Web page in Figure 2.7, and you will be impressed by what can be accomplished with NetShow on demand (NetShow is a component of IIS 3.0 that is used to publish streaming media on the Internet).

Figure 2.7. An ActiveX-enhanced Web page with video and sound.

Cascading Style Sheets

If you are familiar with Microsoft Word or any other application that uses templates for formatting purposes, you can think of Cascading Style Sheets (CSS) as Web templates. Cascading Style Sheets define the appearance of elements of a Web page such as the color, point size, and font of headings. CSS also gives Web-page designers complete control over the placement of elements of a Web page. Cascading Style Sheets can be used to richly format the text and graphics of a Web page. See Figure 2.8 for an example of how Cascading Style Sheets can be used to create visually appealing Web pages. The text you see on the left side of this page is formatted using Cascading Style Sheets. Notice how the text formatted with Cascading Style Sheets looks identical to the graphics file you see on the right side of the page. The only difference is that the graphics file is more than ten times larger than the code required to format the text with Cascading Style Sheets.

Figure 2.8. Cascading Style Sheets can be used to create richly formatted Web pages.

Autosearch

Quick! You have ten seconds to find an Enya MIDI file on the Internet. What do you do? Simply type the search string in the URL data-entry text box and press the Enter key. Internet Explorer interfaces with Yahoo!, searches the string you typed, and displays the result (as shown in Figure 2.9). Go ahead and type the string Enya MIDI Files to observe how Internet Explorer uses Yahoo! to find relevant URLs.

Figure 2.9. Internet Explorer Autosearch.

Summary

Internet Explorer is a feature-rich Web browser that can be used to browse information on the Internet. Internet Explorer supports state-of-the-art Web technologies such as ActiveX, Java, client-side scripting, and Cascading Style Sheets. These technologies can be used to develop multimedia-rich and interactive Web pages that are exciting to navigate.


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