Utilizing metaprogramming with method_missing to create methods on the fly

This will be an interesting section. You are going to learn how to create code that will write code inside a Ruby program by leveraging the metaprogramming construct of method_missing. Though it's an advanced Ruby concept, it's fun to learn and I think it'll be handy for you. So let's get started.

Imagine we have a database called Author, and, in it, we have different attributes, such as first_name, last_name, and genre. What do we do if we want to create dynamic methods on the fly? For example, if we create a new author in the database, we want custom methods to print out each of the attributes. At the same time, we don't want to hardcode a bunch of methods; we want them to get generated dynamically. Essentially, we want a metaprogramming method that will write code dynamically on the fly based on the arguments sent to it.

Let's see how to do that:

require 'ostruct'

class Author
  attr_accessor :first_name, :last_name...