Book Image

Polished Ruby Programming

By : Jeremy Evans
5 (1)
Book Image

Polished Ruby Programming

5 (1)
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)
1
Section 1: Fundamental Ruby Programming Principles
8
Section 2: Ruby Library Programming Principles
17
Section 3: Ruby Web Programming Principles

Implementing your DSL

One of the best aspects of Ruby is how easy Ruby makes it to implement a DSL. After programmer friendliness, probably the main reason you see so many DSLs in Ruby is the simplicity of implementation. There are a few different DSL types you learned about in the previous sections, and you'll learn how to implement each in this section.

The first type is the most basic type, where the DSL method accepts a block that is yielded as an object, and you call methods on the yielded object. For example, the RSpec configuration example could be implemented as follows:

def RSpec.configure
  yield RSpec::Core::Configuration.new
end

In this case, the configuration is global and always affects the RSpec constant, so the RSpec::Configuration instance may not even need a reference to the receiver.

For the Foo.process_bars example given previously, assuming the ProcessBarCommand uses the add_bar method and the DSL uses the simpler bar method, you need...