Inside Technique : Sokoban Level Designer : Client Data Access with HTML Applications
By Rajeev Hariharan

This is the last in a series of articles that discusses the implementation of the DHTML Sokoban game. In the first article, Client-side Data Access, we saw how IE's security model makes it difficult to implement a clean approach to handling data on the client. In this article, we will look at how we used an HTML Application or HTA, a new IE5-only technology, to simplify this thorny task. We will also present a library of common Client Data Access procedures, and take a quick tour of ActiveX Data Objects or ADO, the technology behind these procedures.

Surprisingly little has been written about HTAs, especially considering the fact that they were unleashed on the general public almost a year ago, in the June '98 Developer Preview of IE5. SBN Magazine has a (very) basic Introduction to HTAs, while the official Microsoft documentation contains a mandatory Overview, along with a detailed HTA Reference. If you are new to this technology, we recommend that you follow the links above before proceeding with the rest of this article.

In this article we will look at :

• How HTAs differ from HTML pages
• Using the ADO Connection object
• Using the Microsoft Text Driver
• The ADO Client Data Access procedures

We are releasing the DHTML Sokoban Level Designer along with this article. This is a companion software for the DHTML Sokoban game released earlier, and enables users to create their own gamepacks. This software has been implemented as an HTML Application, and will work only in Internet Explorer 5.

First of all, let us take a look at the basic differences between HTA Applications and HTML pages.

© 1997-2000 InsideDHTML.com, LLC. All rights reserved.