Dynamic HTML: The Definitive Reference

Cross-Platform Position Scripting

Reconciling the differences between the object and rendering models of Navigator 4 and Internet Explorer 4 is one of the biggest challenges you face if you want to script positionable elements for both platforms in the same HTML document. The key factors to take into account are:

• How to address positionable elements when the object references are so vastly different

• How to make adjustments to differently named properties in a truly interactive and dynamic environment

You cannot avoid having your scripts branch to execute platform-specific statements. What you must decide for your application is how and where the branching occurs. There are three basic techniques you can use to implement cross-platform position scripting in a document:

• Explicit branching

• Platform-equivalent referencing

• Custom APIs

Explicit branching and platform-equivalent referencing place the branching code directly in your scripts. For a limited amount of scripted positioning, having all the branching code in your scripts is manageable and actually easier to debug. But if you are doing a serious amounts of scripted positioning, a custom API lets you push the ugly branching code off to the side in an external library. In essence, you create a meta-language that gives you control over the specific syntax used in both browsers. A custom API requires a lot more work up front, but once the API code is debugged, the API simplifies not only the current scripting job, but any subsequent ...