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)
Section 1: Fundamental Ruby Programming Principles
Section 2: Ruby Library Programming Principles
Section 3: Ruby Web Programming Principles

Implementing the most common Ruby refactoring techniques

Two refactoring techniques are very common in Ruby, extracting a method and extracting a class. Let's focus first on extracting a method, as that is more common.

Extracting a method

Extracting a method is generally done when you have found the same code or same pattern of code in multiple places that is being executed for the same reasons.

As an example of this, consider a SQL database library that needs to execute INSERT, UPDATE, and DELETE SQL queries to modify data.

You have a Database class with separate methods to handle each type of query. The insert method checks out a connection, executes the SQL for the INSERT statement on the connection, and uses ensure to make sure the connection is checked back in, because you do not want to leak connections if an exception is raised. Refer to the following code block:

class Database
  def insert(*args)
    conn = checkout_connection...