Throughout this book you have seen type libraries or object libraries, such as those described in Chapter 17, used to enhance functionality through VBA code. You know how libraries can provide access to functions that manipulate the Windows System Registry or retrieve and send data to other applications.
In addition to using libraries supplied with Microsoft Office, you can acquire type libraries to help simplify a variety of programming tasks. Like Microsoft Office libraries, other vendors' libraries provide classes to manipulate objects — the QuickBooks libraries are provided in the QuickBooks Software Development Kit (SDK), for example. These libraries provide classes you can use to create objects that contain data that is returned from a QuickBooks data file through an XML access method.
Acquiring libraries can be a cost-effective way to get more work done in less time. Of course, there's always the tradeoff between what you pay for a library and the effort that may be required to learn how to use it, and the time and effort you spend writing your own functions. And don't forget the effort you have already put into writing your own code. After all of the "bold, test, and swears" you put into your routines, you really must consider creating code libraries from your code.
This appendix describes techniques for using references to libraries in your projects, including how to reference libraries provided by others and why the order of your reference ...