Book Image

Polished Ruby Programming

By : Jeremy Evans
Book Image

Polished Ruby Programming

By: Jeremy Evans

Overview of this book

Anyone striving to become an expert Ruby programmer needs to be able to write maintainable applications. Polished Ruby Programming will help you get better at designing scalable and robust Ruby programs, so that no matter how big the codebase grows, maintaining it will be a breeze. This book takes you on a journey through implementation approaches for many common programming situations, the trade-offs inherent in each approach, and why you may choose to use different approaches in different situations. You'll start by refreshing Ruby fundamentals, such as correctly using core classes, class and method design, variable usage, error handling, and code formatting. Then you'll move on to higher-level programming principles, such as library design, use of metaprogramming and domain-specific languages, and refactoring. Finally, you'll learn principles specific to web application development, such as how to choose a database and web framework, and how to use advanced security features. By the end of this Ruby programming book, you’ll be a well rounded web developer with a deep understanding of Ruby. While most code examples and principles discussed in the book apply to all Ruby versions, some examples and principles are specific to Ruby 3.0, the latest release at the time of publication.
Table of Contents (23 chapters)
Section 1: Fundamental Ruby Programming Principles
Section 2: Ruby Library Programming Principles
Section 3: Ruby Web Programming Principles

Understanding globally frozen, locally mutable design

You learned in Chapter 3, Proper Variable Usage, about the benefits of frozen objects with an unfrozen internal cache. It is usually a good idea to freeze an object you do not plan to modify. This principle extends not just to regular objects, but to classes and modules as well.

In general, when you first load a library, you don't want it to be frozen, because then you cannot modify it. When Ruby starts up, it doesn't have any frozen classes; it allows the programmer to modify every class. This flexibility is very important during application setup. During application setup, before you start accepting user input, you generally want to have complete control to modify any part of the program.

However, in general, after application setup, this flexibility is unnecessary and can be actively harmful. In most cases, you don't want the classes or modules in your application to be modified at runtime. Modifying instances...