Chapter 7 -- Class, Form, and Report Modules

Chapter 7

To program Microsoft Access efficiently, you must manage your programmatic resources so that they are easy to use and reuse. The value of code grows in proportion to how much use you can get from it.

Class modules package code for easy reuse. The class module acts as a container that exposes the code and selected variables inside it in a way that is familiar to Microsoft Visual Basic for Applications (VBA) developers. Basically, you invoke class procedures and assign values to variables with the same syntax used for the properties and methods of built-in Access objects. To use the code in a class module, you do not have to know anything about how it works. Also, since class modules expose properties, methods, and events like other objects do, even beginning VBA developers can use them.

This chapter first introduces standalone class modules and form and report class modules. Then it demonstrates simple ways to build classes into your Access applications and to develop custom properties and methods. Next comes a case study that uses three forms, a few custom Property Get and Property Let functions, and a couple of techniques based on ActiveX Data Objects (ADO) to start building an application. The section after the case study shows the syntax for programming events into your custom classes and introduces the WithEvents keyword.

The focus then shifts to the containers for class, form, and report modules as we look at the All collections that are new to Access 2000. Just as there are AllForms and AllReports collections, there is an AllModules collection. (In fact, there are ten All collections altogether.) The chapter wraps up by explaining how to combine the AllModules collection with the Modules collection to manage code in an application.