Who Needs This Book?
We love Visual FoxPro. We'd rather use it to develop applications than any other product we've ever worked with.But (isn't there always a "but"?) Visual FoxPro isn't perfect. Some parts of the language don't work as they should. Others do what they're supposed to, but we can't imagine why anyone thinks you'd want to do that. And some pieces do exactly what they're supposed to and it's a good thing to do, but it's hard as heck to understand. We should add that the Visual FoxPro documentation is good—in fact, it gets better with each new version—but there are still too many places where it's incorrect, incomplete, or sometimes a bit incomprehensible.Enter this book. This is the book for the times when you've done just as the manual shows, but it still doesn't work and you're running out of hair to pull out. It's for those days when you think you've found a command that does what you need, but you can't make any sense of what Help has to say about it. We'll tell you how it really works or why you shouldn't do it the way the manual shows—or tell you that it doesn't work at all, and show you how to do it another way.What This Book Is Not
This is an "intermediate-level" book. This book is not a replacement for the online Help or the Language Reference manual. It's a supplement. If something works the way it's documented, we won't repeat all the gory details. Instead, we summarize that and add anything the manual doesn't tell you.On the other hand, if a command or function or property or event or method doesn't work as documented or if the documentation doesn't make sense, we dig down and explain it in detail. And, of course, in those cases, we still tell you the stuff the manual doesn't say.This book is not the way to begin learning Visual FoxPro. Other books out there, including Whil Hentzen's book in this series, The Fundamentals, are designed to teach you Visual FoxPro. If you're new to Visual FoxPro, get one of those books and work your way through it. Then get this book to help you move on.This book is not a guide to the Visual FoxPro IDE. While we do talk about the tools and even provide some tips and tricks on that front, this book really focuses on the programming language itself. This book is not an advanced application framework. There are several good commercial frameworks available that will provide you with all the code you need to start plugging your information into their systems and getting working apps out the other end. In fact, Visual FoxPro (beginning with version 6) even comes with a decent framework you can use right away. We like and work with several of the frameworks, and we do not intend to duplicate their work here. Instead, we try to provide an advanced reference when you need to step outside the framework's box, or need to troubleshoot something the framework isn't doing right. You may also use this book to develop your own framework, but that exercise, as our professors loved to say, is left to the student.We assume you're already familiar with the basics of Visual FoxPro, that you know how to use the Power Tools, and that you've spent some time with the product. Although we cover some introductory material, it's not at the level you'd want if you're a beginner.So Who Does Need This Book?
Immodestly, we say anyone who's serious about working in Visual FoxPro needs this book at his or her side. Once you've gotten past the "Help, I don't know where to begin" stage and spent some time working with Visual FoxPro, you're ready. As soon as you've spent a long day and a sleepless night fighting one of the less-than-intuitive behaviors or trying to make something work that just plain doesn't, you're probably well past ready.In putting together this book, we've learned a tremendous amount about what's going on under the hood. Despite having learned most of it the hard way, we all use the book (in particular, the HTML Help version) every working day. We're looking forward to having this new edition on our desktops to replace the VFP 6 version. If a file could be dog-eared, that one would be.Hacking the Hacker's Guide
In any book of this size, there are bound to be mistakes, omissions, or places we just missed the mark. If you think you've caught us on one of these, drop us an email (via books@hentzenwerke.com) and we'll check it out for the next edition. Check the Hentzenwerke Web site regularly for updates and corrections. To make that easier for you, in the HTML Help version you'll find a button at the end of every topic that'll navigate right to updates for that topic, if there are any.While we do love tracking down FoxPro problems, we're all too busy to do it on a one-to-one basis except for our clients and closest friends. So, if you need help with a particularly complex problem or general advice about how to proceed, please take advantage of one or more of the wonderful online resources for VFP. There's a list of them in "Back o' da Book." (Of course, if that doesn't help, we're always interested in new consulting opportunities.)For what appears truth to the one may appear to be error to the other.
Mahatma Gandhi, 1922
Tamar E. GranorElkins Park, PennsylvaniaTed RocheContoocook, New HampshireDoug HennigRegina, Saskatchewan, CanadaDella MartinCary, North Carolina