Volume Number: 13 (1997)
Issue Number: 6
Column Tag: MacTech Online
by Nicholas C. "nick.c" DeMello, URLs@mactech.com
The web has come to life. Every page you bounce off of these days has a popup menu for navigation, a ticking clock, or an animated banner. It's exciting, it's stimulating, hey -- it's fun. Well... at least it is until your client asks why those same bells and whistles aren't chiming on his page. If you're trying to make things happen on a web site, I've got some good news for you. You don't have to create all those spectacular effects -- most of the time, you just need to know where to download them.
When folks decided it was time to liven up the web, they determined that there were at least two ways to go about doing it. The first strategy was just to figure out how to control the web elements we were already familiar with. How do we script the behavior of images, windows, tables, text, links, and panes? Based on Sun's Java language the JavaScript command language was developed by Netscape Communications. JavaScript was originally codenamed Mocha, and then LiveScript. A brief overview of it's history and origins has been put on the net by Frank Hecker.
JavaScript is written directly into your HTML code between <SCRIPT>...</SCRIPT> tags, and is interpreted by your browser at runtime. The language is extremely easy to learn, especially with the aid of online resources like the JavaScript 411 pages. JavaScript 411 maintains a JavaScript FAQ as well as a tutorial. Another useful tutorial is Stefan Koch's "Voodoo" introduction to JavaScript, which will take you from "Hello World" to dynamically building new pages for your user. But the real wealth in online resources are the example code and libraries of reusable JavaScript functions, like the JavaScript Planet website and Netscapes JavaScript Guide. Also, be sure to check out Nick Heinle's JavaScript Tip of the week.
Sometimes, JavaScript isn't enough. Applets -- compiled binaries of Java code -- offer an extension of HTML. Applets can be embedded into HTML documents the same way a gif or jpeg can. The Java virtual machine incorporated into Internet Explorer and versions of Netscape Navigator 2.0 or greater interprets and executes the logic in the applets. Unlike JavaScript, which is limited to manipulating HTML elements, Java is a complete modern language and limited only by your imagination. I'll touch on online references related to creating applets in a future column, lets talk today about the component relationship of applets in HTML. Let's talk about using applets.
Compiled applets for implementing a clock, blinking text, scrolling images, and sounding audio files exist at the Café del Sol. The online Café gives you a complete description of what parameters to pass to them and how to add these applets to your web pages, but if you need a little more info Sun has put a complete description of how to insert applets into HTML. Other places to download component applets include the JavaSoft applet archive and the hot applet picks of the month at the Gamelin site. Make sure you explore the rest of Gamelin when you visit that site, Gamelin is a tremendous resource of applets and other Java information.
In two months MacTech Online is going to get serious about Java. Below are some Java online resources to explore between now then. We'll leave you with some links to important component technologies. These and other links are accessible at the MacTech URL database www.mactech.com/magazine/urls/. See you next month.
