(281 words)

The principle of YAGNI should always apply, and I was recently reminded of that when I had to build a small application to give to a user for a small one off task. We’re talking a single screen application with a single button on it. Idiot proof.

So, File > New > Winforms application - doesn’t have to be anything fancy. Then I caught myself: My first instinct was to add StructureMap to it.

I thought to myself that it’s only going to have a few classes, I mean just because it’s a small winforms app doesn’t mean I’m going to shit up the code behind with business logic and data access, so why bother with the overhead of adding a IOC library?

It doesn’t mean I don’t have to use dependency injection. Mark Seemann calls this “Poor Man’s DI”.

    static class Program
    {
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);

            var service = new Service(new Database(), new Other());
            Application.Run(new Main(service));
        }
    }

It’s short and sweet, and there is no IOC container configuration to worry about. Because I don’t need to.

What about when….

Requirements change. “Can it just do this as well…?” More dependencies required, perhaps another form, maybe another service or two. I think I’d see how far I could push Poor Man’s DI before I brought in a proper IOC container to help manage things.


Stuart Grassie

A software developer in the North of England.