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

Designing your DSL

The most important thing to think about when designing a DSL is to focus on how the DSL will be used. Some DSLs are designed to configure a library. Some DSLs are used for making specific changes using the library. Some DSLs exist purely to reduce the verbosity of the code. Sometimes the library exposes a DSL as its only interface, and the library and DSL are basically the same thing. Let's focus first on DSLs designed for configuring a library.

Configuration DSLs

DSLs designed to configure libraries are often referred to as configuration DSLs. They are often initiated from a singleton method on the library's main module or class, often straightforwardly named configure. RSpec, a popular Ruby library for testing, uses a configuration DSL like this:

RSpec.configure do |c|
  c.drb = true
  c.drb_port = 24601
  c.around do |spec|
    DB.transaction(rollback: :always, &spec)