JavaScript Resources

Other Dynamic and Interactive Tools

JavaScript is one way to add interactivity to a web page, but there are many other tools at your disposal. These methods share many features and in many ways are in competition with each other. They will also seem confusing until you dive in and try them out, but, in either case, here are some quick overviews.


Java

Java is a full-featured programming language that pre-dates and has a whole other existence outside of the Web. It is a much more powerful programming tool than JavaScript.

As a full-featured programming language it has the ability to do anything that you can conceive for a programming language. It can, for example, create animations, play sounds, move items on the screen, and communicate with a server or a database. On a larger scale, it could conceivably be used to build programs (like Microsoft Word or Netscape Navigator) or even operating systems (such as OS 8 or Windows98). It is not limited to the Web or to a Mac or to a PC or even to a desktop computer. As a matter of fact, in the not too distant future, Java might possibly be the language that not only operates your Microwave, remote control, and wrist watch, but also allows these devices to communicate with each other! (Not that they'd have too much to say to one another). :-)

Java when used in web browsers is called a "Java Applet" and is just a way to add full-programming capability to the browser. To add a layer of confusion, JavaScript can be used to communicate with, but not create, Java Applets .


CGI

One of JavaScript's limitations is that it cannot be used to store information obtained from the user in any permanent way. When the user leaves your page, so does any data (although "Cookies" can be used to save small amounts of temporary information on the user's computer, but nothing sizeable).

If you want to process information in a form on your web page, i.e. make a guestbook entry, add a user to your mailing list, or collect and permanently save information from the user in any way, you must use CGI (Common Gateway Interface). CGI is a set of standards or protocols that define how information can be passed from a client (the user's computer) to the server via a web browser. The term CGI refers simply to the set of agreed upon standards; it is not a language itself. To actually collect and process the information you must write a script in a language that understands the CGI protocol. Scripts are written in any of the following languages: C, C++, Perl, UNIX Shell, Java, Visual Basic, AppleScript, or TCL. Perl, however, is the most popular scripting language for CGI. CGI scripts are separate files that are not embedded in your HTML code.


Dynamic HTML (DHTML)

DHTML is a bit of a misnomer. It is not a separate language. Instead, it is a fusion of client-side scripting (e.g. usually using the JavaScript language) and Cascading Style Sheets (CSS) which are a part of the HTML 4.0 specifications. It encompasses a variety of functionality that you can add to your page. However, I think that most people think of DHTML as the stuff that makes your web page act more like an interactive CD-ROM without requiring a plug-in and a significant increase in download time for the user. Here are some examples that I think will give you some sense of what DHTML can do. Yyou will need Netscape 4 or greater to view these.

  • Randomly moving images that also follow your cursor.

  • Collapsible menu list

  • If you are a member of Generation X, this interactive game needs no introduction. Be sure to click on "what will happen" to see the game.

  • Here is an arcade game that Generation Xers should also recognize. (It will take a long time to download, do not try with anything less than a 56K modem).

VB Script

JavaScript and JScript are not the only client-side scripting languages. If you are a PC user, you can also use Visual Basic Script, a.k.a. VB Script, to script your pages (for Internet Explorer only). Visual Basic is a subset of the Visual Basic programming language.

Shockwave

Shockwave and Flash, created by Macromedia, are plug-ins for web browsers. Plug-ins are applications that extend the ability of a web browser. These particular plug-ins enable web browsers to easily display full-screen animations and multimedia presentations. Shockwave files are created using a program called Director - a CD-ROM authoring tool. Shockwave has a number of uses, but is mainly known as a way to translate content developed for CD-ROM to the web.

Flash

Flash, also a Macromedia product, is a technology developed specifically for the web that gives developers the ability to create interactive, vector-based animations. It is much like Shockwave and Director, however, the big difference is that Flash files are not bitmapped (as GIFs and JPEGs are) - which makes Flash files significantly smaller. Flash consists of two components as well - the Flash software which allows you to create these files (or "movies") and the Flash plug-in which allows users to play these files in their browsers.

If you are unclear about the differences between Shockwave and Flash, check out this WebMonkey article.


Animated GIF Format

An animated GIF is not a programming language nor is it as powerful as the tools listed above, but I list it here because it is often used as a way to add dynamic content to a page. It is basically an image that is an animation, i.e. a sequence of GIF images that are played like a cartoon or slide show. Animated GIFs are created with special software (that is freely available on the web) and inserted into your web page in the same manner that all other images are inserted - using the <IMG SRC> tag.

Many, but certainly not all, of the animations that you encounter on the web are animated GIFs. There are other methods to create animations available to you (you can also use any of the methods listed above), but the animated GIF format is the easiest to learn and work with. Keep in mind that there is no animated JPEG format. If you want to create an animation that uses images in the JPEG format, you will have to use JavaScript or one of the above methods.

"GifBuilder" (Mac) and "WebReady's Giffy the GIF Animation Builder" (PC) are the two most popular shareware programs to create GIF animations. You can find at Download.com.