The Open-Closed Principle states that software should be open for extension but closed for modification. While this SOLID principle can be implemented through inheritance or the Strategy pattern, it shouldn't be applied blindly. Ruby's dynamic nature makes strict OCP adherence nearly impossible, as classes remain open at runtime. The key is recognizing when extensibility adds value versus when it creates unnecessary complexity. Start with simple solutions and refactor toward extensible designs only when you experience actual pain from modifications. Context matters more than rigid principle adherence.
Table of contents
The Promise of the Open-Closed PrincipleA Practical Example: The User ExporterApplying the Principle: Extension via InheritanceA More Flexible Alternative: Composition with Strategy PatternDid We Really Need All This?Context Matters: When to Apply OCPThe Technical Reality of Ruby: OCP is Almost ImpossibleA Pragmatic PerspectiveConclusionSort: