Understanding the Gang of Four design patterns is a valuable bit of knowledge for a programmer. Of course, instead of understanding them, it sometimes seems like most design pattern fans just… use them. Sometimes- often- overuse them. The Java Spring Framework infamously has classes with names like SimpleBeanFactoryAwareAspectInstanceFactory. Whether that's a proper use of patterns and naming conventions is a choice I leave to the reader, but boy do I hate looking at it.

The GoF patterns break down into four major categories: Behavioral, Structural, Concurrency, and Creational patterns. The Creational category, as the name implies, is all about code which can be used to create instances of objects, like that Factory class above. It is a useful collection of patterns for writing reusable, testable, and modular code. Most Dependency Injection/Inversion of Control frameworks are really just applied creational patterns.

It’s generally hard to do worse than a SQL injection vulnerability. Data access is fundamental to pretty much every application, and every programming environment has some set of rich tools that make it easy to write powerful, flexible queries without leaving yourself open to SQL injection attacks.

And yet, and yet, they’re practically a standard feature of bad code. I suppose that’s what makes it bad code.

About three years ago, Consuela inherited a giant .NET project. It was… not good. To communicate how “not good” it was, Consuela had a lot of possible submissions. Sending the worst code might be the obvious choice, but it wouldn’t give a good sense of just how bad the whole thing was, so they opted instead to find something that could roughly be called the “median” quality.

This is a stored procedure that is roughly about the median sample of the overall code. Half of it is better, but half of it gets much, much worse.

The C# "extension method" feature lets you implement static methods which "magically" act like they're instance methods. It's a neat feature which the .NET Framework uses extensively. It's also a great way to implement some convenience functions.

Brandt found some "convenience" functions which were exploiting this feature.

One of my favorite illusions is the progress bar. Even the worst, most inaccurate progress bar will make an application feel faster. The simple feedback which promises "something is happening" alters the users' sense of time.

So, let's say you're implementing a JavaScript progress bar. You need to decide if you are "in progress" or not. So you need to check: if there is a progress value, and the progress value is less than 100, you're still in progress.