Visual Basic 6: Error Coding and Layering (Prentice Hall Series on Microsoft Technologies) [Paperback]

After reading the first 6 chapters there was no way I would let our staff read this book. Why?

First it is full of incredibly bad programming practices. The author talks about code reuse, which is a concept I am all for. However he his definition of code reuse is to share a module (.BAS) between all your applications, which is a horribly bad thing to do. Code reuse should be 'black box', ie ActiveX dlls or controls.

Second point is the book talks about things which are simply not true in VB6. A good example is section 5.5, where he talks about how error handlers work. He talks about the scope of a ON ERROR command -- which he says is only in the current routine, and not any called by the it. This as all VB6 programmers knows is wrong. He also talks about the string parsers such as MID which fail if you ask for something outside the string length which is also not the case. It would seem this book has been written for VB4 as these problems probably were an issue then. (Wasnt for VB5)

Third is the horrendous wrapping he performs. He actually wraps the MSGBOX function, to avoid a null being passed into the message. Come on! Any VB programmer knows this is a completely pointless exercise. (In fact the function he suggests does not allow you to pass other MSGBOX parameters)

Fourth is the very bad UI design. He suggests if a user doesn't enter a valid value you should not be able to move away from the textbox. (For example.) This is the worst thing you can do. SETFOCUS should only be used in the most exceptional circumstances. It could cause the machine to hang -- as two controls fight for focus, or at the very best frustrate the user. For example, if I would not be able to move away from the textbox to copy data to paste to it.

I can go on. He uses variants to much, he suggests always using named parameters. (How much extra time would that take, and for what? A function definition should be static.)

He does suggest some good points, like clearing pointers (setting objects to nothing) and sensible variable definition. But the bad completely out weighs the good. Avoid. (And dont give it to young and impressionable programmers.)

Among an absurdly large crowd of dreadful books on VB 6, I found "Error Coding and Layering" singularly useful and applicable to anyone writing Windows apps in VB.

The error coding technique proposed is clearly explained, and is proving practical and robust. Far from being cumbersome, as some reviewers suggest, it is easy to implement and helps avoid code bloat.

There is a clearly specified framework for the technique, and useful guidelines about how the standards can be introduced, certified and sustained in a development team.

As a bonus, there is a short but meaty section on an architectural approach which seems to offer a number of advantages over conventional tiered approaches.

The text claims the approach has been used with success in several large commercial projects and this rings true - there is a strong sense that these are practical lessons learned at the coal-face and not in the ivory tower.

Please don't be put off this book by the negative reviews below - they are somewhat baffling as most of the criticisms are factually incorrect. For example, the author does not ignore the importance of dlls in code reuse, does not ignore error logging, does not lock users into a text field using SETFOCUS, does not recommend always using named parameters etc etc. For whatever reason, these reviewers haven't given the book a fair reading.