31 May 2008

Frameworks and the danger of a grand design

Frameworks and the danger of a grand design

This isn't really something that can be taught, at least not in such a way that it really drums the lesson home. You have to experience the pain of creating an over-designed "framework for the sake of it", believing in all good faith that your grand design will help, not hinder, maintainability.

The grand design mindset isn't just the application of an anti-pattern, or even just the inappropriate use of a normally well-behaved design pattern. The mindset is the overuse of patterns, carefully cementing nano-thin layers of indirection atop each other like a process in a chip fabrication plant that can't be shut down. It's the naïve belief that if X is good then 100X must be better every time.

Luckily this mindset is easy to spot. Your team members will be busy creating a beautiful but over-designed system with enums, annotiations, closures and all the latest language features, loosely coupled classes and several hundred pluggable frameworks when a well-placed isThisTheRightValue() method would probably have sufficed.

Picture a pluggable framework that only ever has one plug. You'll see a comment in the code like, "Later this could be applied to other parts of the system."

If there's neither time nor a compelling reason to apply the pluggable framework to other parts of the system in this iteration, then it's likely the programmer going off on a design pattern hike - exploring their talents - and the framework should be struck out of the code. It's just more complexity to maintain.

Of course, some programmers will never learn: they like writing code too much. Lots of it, as if they're paid in lines of code, or reviewed that way. Or maybe it's a macho thing. Pursuing your own grand design will do that for you, but it's better to solve problems with little code. Less is more.