OOP Fundamentals: The Decorator Pattern

The decorator pattern is one of my favorite patterns. It is simple, extensible and powerful. It feels like it follows the essence of object oriented programming beautifully. Sadly though, it is also easy to be misused or misunderstood. So, in this post I will show you the essence of the decorator pattern, illustrated with a few examples.

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OOP Fundamentals: The Dependency Inversion Principle

The dependency inversion principle is one of the cornerstones of object-oriented programming. Without it, there is no object-oriented design. It’s that important.

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Something out of Nothing: Null Object Pattern

What is nothing? nil? null? undefined? A vast void of emptiness that fills your soul with dread? Oh sorry, that’s just my stomach.

We often think of nothing as… well, nothing. It’s when something doesn’t exist and therefore cannot be interacted with. So in our code, we try account for having nothing. No User? No problem.

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Composition over Inheritance, with JavaScript examples

If you are into object-oriented programming, you most likely have heard about composition over inheritance. The concept itself is simple: Whenever possible, prefer to compose objects rather than introducing inheritance.

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Common Code Smells in OOP

Over years of reviewing Ruby code, the same things tend to come up over and over. In this post, I’d like to address some of the most common code smells I find when reviewing OOP code (and Ruby code in particular).

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