Chapter 16 -- Using Client Database Features

Chapter 16

As we saw in Chapter 7, Dynamic HTML (DHTML) is basically HTML with additions that allow scriptable changes to a document at run time. You can change nearly everything about the document content at run time by using a scripting language such as Microsoft VBScript (Visual Basic, Scripting Edition) or Microsoft JScript to access the HTML objects. Every element in the document becomes an individually addressable object at run time. Objects are very simple, consistent, run-time-programmable entities. In Chapter 7, we looked at several elements of DHTML, including the DHTML object model, dynamic styles, dynamic positioning, and dynamic content. In this chapter, we'll take a look at another key feature of DHTML provided by Microsoft Internet Explorer 4.0—data binding.

In Chapter 13, we saw how the scripting platform can be changed from server side to client side, thus moving the data to the client side for greater user interactivity and performance. Users are able to filter and sort data on the client side without having to take round-trips to the server. Additionally, users can page through a form displaying a single record at a time without having to take a round-trip to the server each time. Not only does this work for viewing and navigating through data, it also works for recordsets that need to be updatable so that the user can add, edit, and delete records where necessary.

All this actually occurs through data binding. Microsoft Visual InterDev 6.0 makes it easy to incorporate data binding into your applications via the development environment using the Scripting Object Model, Recordset objects, design-time controls, and DHTML so that you don't have to be concerned with the internals of how data binding is implemented.

In this chapter, we'll take a look at data binding both in theory and in practice. We'll look at how to use this technique within and outside the Visual InterDev environment—meaning with or without Recordset objects and design-time controls. Exploring the internals of data binding will give you more insight into how this mechanism works and into the endless possibilities for using it within your business applications. We'll start with the theory and then get into some code samples that illustrate how to apply data binding in your applications.