A DOM-Based Snakes Game, Part I

A DOM-Based Snakes Game, Part I

The DOM is getting very popular. It's being touted as the best thing since sliced bread. Experts foresee two types of Web programmers: those that use DHTML and those that master the DOM. They argue that DHTML expertise will be less valuable in the future, and that DOM expertise will prevail. To prepare you for the challenges ahead, we'll present here our second DOM-based application - the Snakes game. This game can be played on several cellular phone models and hence is getting very popular. Go ahead and try it now.

This column will get you more comfortable writing DOM-based applications. Since the DOM is a W3C standard, there is a better chance that it will be supported by both main browsers, relieving you from the heavy duty workarounds of browser-dependent programming. Browser-independent DOM-based programming is much easier than HTML- or DHTML-based programming. In this column, you'll learn how to design and architect your application as well as how to structure its code. We'll show you different ways to use the DOM's properties and methods, eliminating almost completely the need for the DHTML Model. The Snakes game demonstrates that it is possible to build a Web application almost without any HTML statements.

This column is also a continuation of the JavaScript programming refresher from our previous column. This column is heavier in content than the Sliding Puzzle so pay close attention! As we did in our previous column, we'll go over the script line by line and explain to you its ins and outs. In this column, we'll show you the DOM's role in the script, and how is the application built around it. In the next column we'll complete the detailed explanations of the scripts' functions.

In particular, you'll learn:

• How to architect the application
• How to analyze its DOM tree
• How to write the main program
• How to select the right global variables
• How to find the browser's version

We also include the game's complete listing and its zipped version as well.

Produced by Yehuda Shiran and Tomer Shiran

Created: Aug 16, 1999
Revised: Aug 16, 1999

URL: https://www.webreference.com/js/column46/