Chapter 3

Netscape Navigator 2.0: The World Wide Web on a Caffeine High

In This Chapter

Setting up Netscape Navigator 2.0
Browsin' and jivin'
Documentation: It's all in there!
Canned applets (delicious!)

Let's Brew Up a Browser

Whereas JavaScript is the language, Netscape Navigator 2.0 is the browser that understands the language (making all those nifty, little scripts sing and dance on your Web page). In the future-perhaps by the time you read this-other browsers may also support JavaScript, such as Microsoft's Internet Explorer. At this writing, though, Netscape Navigator 2.0 is the only game in town. Before you dive headlong into the world of creating JavaScript pages, you need to get comfortable with the browser that plays it all back for you (or whoever else accesses your pages).

Where Can I Get a Cup?

But I Already Have Netscape 1.2!

If you're already using Netscape Navigator (perhaps you purchased it or downloaded version 1.2 some time ago), you still need to upgrade to version 2.0. Netscape Navigator 2.0 is the version that supports JavaScript. If you stay with version 1.2, you won't be able to see the "special effects" that JavaScript produces.

Macintosh and Power PC

Macintosh and Power PC (running the Mac OS) users have it a little easier when it comes to installing Navigator. The file you download is not only self-extracting, it's also self-installing. Once the download is completed, you'll have an icon that, when double-clicked, will do all the unpacking, installation, and icon creation for you.

To dig that Java jive, you need to get Navigator 2.0 up and running. To get your copy from the Internet, grab your current browser (any browser will do) and point it at:
http://www.netscape.com/

An .EXE File That Unpacks Itself?

This is a self-extracting archive, and it's nothing but a fancy way to easily get a compressed file decompressed on your computer without having to figure out how to run (or find) a decompression program (such as WinZip or PKUNZIP). Compressed files are actually collections of files or entire directories packed into one physical file (it's easier to download one large file than 500 small ones). Many of the files you'll find online in and around Web sites are in this format. However, it doesn't hurt to keep a copy of the most popular decompression programs within reach, because you might run into some compressed files that won't extract themselves.

Follow the links to the "Downloading" section (or you can click one of the Netscape NOW 2.0 buttons you'll find liberally sprinkled throughout the pages). Follow the instructions to pick the correct version (Netscape Navigator has versions available for Macintosh, Windows 3.x, Windows 95, Windows NT, and several flavors of UNIX) and begin the download process. This file is over 3 megabytes in size, so once you start the download, you might want to go get a cup of real coffee!

All Right… Now What?

Once you download the file, simply run it-either by double-clicking on it or specifying its name in the Windows Run dialog box, which you access by selecting File, Run in Windows 3.1's Program Manager or Run from the Start Menu in Windows 95. In a perfect universe, the rest of the process should be automatic, and Netscape will walk you through the installation.
After Netscape is installed and working, you may delete the installation file you originally downloaded. However, it might be wise to keep it around until you're confident that Netscape is working, just in case reinstallation is necessary. Wouldn't want to have to download that 3-megabyte file all over again.

When Netscape completes installation, it will create a Program Group with appropriate icons. In Windows 95, it will plop a shortcut to the Navigator on the desktop, all ready for launching.
That's it; you're set. Double-click the Netscape Navigator 2.0 icon and you're off and perking!

Make Sure You're Connected

Netscape Navigator must assume that you already have a properly configured Internet connection. It has no way of knowing this for itself, so if your Internet connection is not working, Netscape will launch but not be able to connect anywhere. You don't need to make any special Internet configurations for Netscape to work-you simply must have a "regular" working Net connection. Most users of Windows 95 use Dial-Up Networking to create this connection; if you're not sure how to set this up, check out one of the several online tutorials at http://www.windows95.com. (Of course, you may have to use someone else's machine to use this tutorial in the first place.)

Just Browsing

With Navigator 2.0 installed, you're ready to take off on a totally new Web adventure; launch Netscape, and you're poised to take on the world. Or at least the World Wide Web.
The first thing you see is the Netscape home page:

Netscape Navigator 2.0, up and running.

The top portion of the browser window is chock-full of buttons that allow you to "drive" the Navigator around the Web.
The toolbar consists of the topmost series of icons in the Navigator window. These are the most commonly used buttons for accessing the major features of the Navigator. From left to right, briefly consider each:

Back Brings you to the previous Web page visited.
Forward Assumes that you have already gone Back from a page; brings you to the page visited subsequent to the current one.
Home Brings you to the defined starting page; by default this is Netscape's home page, although you can set it anywhere you like by selecting Options, General Preferences, Appearance from the Netscape menu bar.
Edit The Edit button exists only in the Netscape Navigator Gold edition and is used for editing a Web page.
Reload Re-retrieves the current URL in question from the server. Sometimes, a page does not load properly; other times, you need to use this button to refresh information that may have changed on the page.
Images If you have not configured for automatic image loading (Options, Auto Load Images), then this button will load all of the images for the current page.
Open Allows you to enter a new URL to connect to; for connecting to a new Web page.
Print Just what you'd think: prints the current page to your printer.
Find Allows you to search for text in the current page.
Stop While a page is loading into your browser, you can click this button to abort the retrieval-perhaps it is taking too long, for instance. Netscape will try to display whatever amount of the page that it has retrieved, if possible. (Often, this is the text without the images.)

The Location window resides below the toolbar. Here, you see the official URL for the current Web page loaded into Navigator. In short, it shows you the address of where you are. Another way to connect to a new page, in addition to the Open button on the toolbar, is to simply click within the Location window and enter a new URL; then press the Enter key. There is a little selection doohickey at the far right of the Location window (a down-pointing arrow symbol), which allows you to select a URL from a list of recently visited sites.

Choose Your Own Adventure: Pages

The World Wide Web (and browsers that use it) handles information using the concept of pages. A page is one window-full of information, although some windows may allow you to scroll up and down them if the page is longer than your screen. As you move from page to page, you create a history of the places you've been. The Forward and Back buttons allow you to move throughout this history list (which you can see by clicking the Go menu). It's an easy way to explore down one path and then "back up" to some point and go in a different direction.

Finally, a row of directory buttons hangs just under the Location window. These buttons automatically bring you to Netscape pages concerning their respective topic. Thus, the What's New! button springs you to Netscape's page of new sites. What's Cool! avails you of Netscape's subjective picks of "cool" sites. The Handbook button leads to online documentation for using the Navigator. Net Search offers you a page of resources that allow for searching the World Wide Web. You can find a breakdown of Web sites by topic via the Net Directory button. Lastly, you can shop for Netscape software through the Software button.
Take note of the Netscape "N" logo on the right side of the window. This logo serves two purposes, other than being a constant source of self-promotion. First, it indicates whether Netscape is currently retrieving data. If so, you will see the "N" slightly animated, with little comets or shooting stars flying behind the "N." When no data is being retrieved, the icon sits still. Second, if you click on the "N" logo, you'll be taken directly to Netscape's home page.
If you've used the previous version of Netscape (version 1.2), you might note that this much-touted version 2.0 doesn't look much different. Don't worry; the fun stuff is under the hood: in the pages, not (visually) in the browser.

Configuration Bonanza

Much of the Netscape Navigator's behavior is dependent on its many configuration settings. You can truly customize this baby, short of pinstriping (well, you could do that, too, but I doubt your monitor manufacturer will take it back). TheOptions menu is your starting point, where you'll look mostly at those options that might have some relevance to Web pages with JavaScript.

The General Preferences Command

This is where the majority of effective settings lie. The General Preferences window (which appears when you select Options, General Preferences) contains seven tabs, labeled "Appearance" through "Language."

Appearance First, you can select what style toolbar you prefer. If you can live without the iconic pictures, a text-only toolbar saves screen space, allowing more content to fit in the browser window.
On startup (launching the browser), you can select whether to have the Web, News, or Mail be your first window. You can also select whether to have an initial Web page upon startup, and if so, which one.
Lastly, you can configure link characteristics. Links are highlighted in the Web page, and can also be underlined for easier recognition if you enable the Underlined option. Netscape will keep track of which links you have followed and will highlight those in a different color upon future visits to a given Web page. You can determine how long Netscape should remember followed links by configuring the Expire option either to Never Expire (Netscape Navigator will always remember them), or to some number of days (it will remember them only for that long, and then treat them as unfollowed).
Fonts These are cosmetic options, and you might want to experiment here. Look for fonts that meet your preferred balance between the amount of content on-screen and readability. The Proportional font refers to the font that most Web page text will be rendered in. The Fixed font is used for unformatted text, which arises less frequently in Web pages. Encoding should be set to Latin1 for English language usage.
Colors Here, Netscape allows you to configure your preferred Web page colors. You can select colors for various states of a link, as well as for the background of the page. You can even set a graphic texture for the background via the Image File selection. However, as the settings window explains, some Web pages define their own colors and backgrounds. With the check box provided, you can select whether to always use your preferred colors, or to allow pages to define their own. In most cases, it's best to allow pages to define their own-since that's part of the author's design-so not checking this option is the best option.
Images Many Web pages contain images (also known as inline images or inline graphics). These settings allow you first to determine how Netscape will choose image colors. Automatic is probably the best option; for users with lower color displays, Dither might produce better-quality images but will take somewhat longer to process. Lastly, you can tell Netscape whether to show images in-progress as they download, or wait until they're finished downloading before popping them onto the page. This is largely a matter of personal preference.
Apps Netscape needs to know the locations of a few external programs that may be called from a Web page. Some pages have links that lead to Telnet addresses--Telnet requires a separate program. Thus, you must tell Netscape where your Telnet program is. Users of Windows 95's built-in networking already have a Telnet program in C:\Windows\telnet.exe. TN3270 is a specific Telnet protocol that sometimes requires a separate program-not all Telnet programs support TN3270. If you have a TN3270 program, enter it here, but if you don't really know, just leave it blank. Not many Web pages are going to require this.
The View Source option lets you choose a text viewer. This will be launched if you select View, Document Source from the Navigator menu bar. It is used to display the page in its native HTML, should you be so interested. Leaving this setting blank will use Netscape's built-in viewer, so you needn't configure this unless you have a preferred text viewer.
Finally, Netscape needs a Temporary Directory for any "scratch pad" space it needs. Usually a directory such as C:\WINDOWS\TEMP or C:\TEMP is a good choice.
Helpers The Helpers settings allow Netscape to use external programs for a variety of needs. Many times, Web pages contain links to files of types that the browser itself is not equipped to view-these might include sound/audio files, certain image files, any special file types such as RealAudio files, 3D VRML files, and so on. The helper definitions tell Netscape which programs to launch when it encounters one of these file types. Although it appears confusing at first, the helper settings screen is decipherable.
The top window contains a list of "known" file types. They are written in a strange way, but usually you can tell by reading their names what sort of files they refer to (for example, "application/zip" refers to a .ZIP file). Beside each file type listing is a column that indicates what the current configuration is: what to do with that file type (ask the user, let the browser handle it, save it, or run a specific program). To the left of that are the file name extensions that relate to that file type (thus, zip would be a file name extension for a zip file type). Netscape Navigator comes with a large list of file types pre-installed. Many of these are also already preconfigured. If you highlight a file type, you can then reconfigure what to do with it in the entries below the file type window.
This includes listing the file name extensions, and whether to save the file, ask the user, or launch a specific application. You don't often need to work with these helper settings, but it's useful to understand what they mean. If you find that a certain type of file is not being viewed/played/launched properly, the first course of action is to run to the helper settings and check the configuration for that file type. Is the file type listed? Is it configured to launch a program? Do you actually have the program it is configured to launch?
Language The language setting isn't used terribly often. It allows you to select a "preferred" language. Some servers offer a document in several languages-if you have selected a preferred language that the server can offer, it will. Most people, most of the time, leave this setting blank, since English is obviously assumed by default.

The Mail and News Preferences Command

Netscape Navigator also includes a built-in e-mail facility and Usenet newsreader. These settings affect the operation of both. By and large, e-mail and newsreading are not Web functions, and thus have little relation to JavaScript.
When you select Mail and News Preferences from the Options menu, you see another Preferences dialog box, which contains five tabs filled with more settings. In brief, the most important of these settings involves entering server names; your Internet service provider should have supplied you with names for POP, STMP (both for e-mail), and NNTP (for news) servers. Fill these in the appropriate places where the Mail and News preferences ask for them.
Also, be sure to fill in at least a name and an e-mail address in the Identity tab of this Preferences dialog box. This way, if you do send e-mail to someone else via a Web page, it will have the proper return address.

The Security Preferences Command

In the Preferences dialog box that appears when you select Options, Security Preferences, consider one option: the one labeled Disable Java. If you check this option, Java applets will not be run. However, this does not affect JavaScript programs. At least, as of the version of Netscape Navigator 2.0 at this writing, JavaScript programs are always executed, without relation to enabling or disabling Java support itself (remember that Java and JavaScript are virtually two different creatures).

Where Are the Manuals?

There aren't any. At least, at this point in time, there are no existing, "print" manuals that cover JavaScript or its use with the Netscape Navigator. That situation may or may not change by the time this book hits the shelves.
Netscape does, however, provide relatively thorough JavaScript documentation on its Web site, including tutorials, examples, and reference material. You can find this at
http://home.netscape.com/comprod/products/navigator/version_2.0/script/
In addition, check out the JavaScript Support Page maintained by the authors of this book:
http://www.winternet.com/~SJWalter/JavaScript/
Either place provides you with a wealth of additional knowledge (possibly more than most mortals would care to know). For the bulk of this book, however, you'll be looking at the author's JavaScript Support Page (add it to your bookmark list; then tell your friends!).

Applets and Oranges

Netscape Navigator 2.0 not only supports JavaScript but also its big sibling, Java. Java is a full-blown programming language, allowing you to do some absolutely phenomenal things through the Web (JavaScript is no slouch, and you'll be pleasantly surprised by how powerful it really is).
Although this book is not about Java itself, it would serve you well to understand the differences between the two. They are, after all, easy to confuse given that they both share at least part of the name Java.
Java is a high-level programming language-those readers familiar with C or especially C++ will understand what that means. Java is, in fact, a close relative of C++. This makes it very powerful-a creative programmer will have a lot of latitude. A Java program is known as an "applet" (small application), and these applets can be included at various points in Web pages.
Java applets can perform virtually anything the programmer can figure out how to program, from user interaction to calculations to graphical events such as animated pictures or text. The sky's the limit with Java, but there is a price to pay: it has a high learning curve and isn't necessarily the ideal programming language for a novice user.
Enter JavaScript. JavaScript was inspired by Java; in other words, the two are based around many shared concepts. However, it is far simpler to program. There are fewer rules and fewer concepts that require a computer science degree for you to program in JavaScript. In theory, this does limit the "sky" as far as JavaScript vs. Java goes. However, most novice users with limited or no programming experience should find JavaScript quite accessible and capable of many Web page needs. The language is small and compact, making learning and programming JavaScript quite manageable and, dare I say, even fun. Readers with experience programming in Pascal or scripting in PERL will find JavaScript a breeze.
If you are curious or adventurous, and want to learn more about Java itself, you might start with Java's official home page at
http://java.sun.com
In addition, while you're here, don't forget to check out Chapter 22 of this very book. It's way near the back.

The Least You Need To Know

This chapter showed you how to start with the Netscape Navigator 2.0 browser. You grabbed a copy from the Internet, installed it, and fired it up. You tried the few buttons that run the browser and spent some quality time configuring. You now understand the difference between Java and JavaScript, and why this book is about the latter.
However, the real fun begins when you start creating your own JavaScript pages, complete with animation, sound, and other nifty things. In order to start with that, you need to see how to plug scripts into your Web pages-and that's what you'll look at next.

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