Included hook in Ruby - Mini Project: Build & Apply

Using the Included Hook in Ruby Modules

📖 Scenario: Imagine you are building a simple system where different classes can share a greeting message. You want to use a Ruby module to add this greeting feature to any class that includes it. To make it more interesting, you want to print a message automatically when the module is included in a class.

🎯 Goal: You will create a Ruby module with an included hook that prints a message when included. Then, you will include this module in a class and use the shared greeting method.

📋 What You'll Learn

Create a module called Greeter with a method greet that returns the string "Hello!".

Add an included hook inside the Greeter module that prints "Greeter module included!" when the module is included in a class.

Create a class called Person that includes the Greeter module.

Create an instance of Person and call the greet method, then print the result.

💡 Why This Matters

🌍 Real World

Modules with included hooks are useful to add shared behavior and setup code automatically when modules are included in classes, common in Ruby libraries and frameworks.

💼 Career

Understanding modules and hooks is important for Ruby developers working on code reuse, gems, and Rails applications.

1

Create the Greeter module with a greet method

Create a module called Greeter with a method greet that returns the string "Hello!".

Ruby

module Greeter
  # Your code here
end

Need a hint?

Define a module with module Greeter and add a method greet that returns the greeting string.

2

Add the included hook to the Greeter module

Inside the Greeter module, add an included hook method that takes a parameter base and prints "Greeter module included!".

Ruby

module Greeter
  def greet
    "Hello!"
  end

  # Your code here
end

Need a hint?

The included hook is a class method inside the module. Use def self.included(base) to define it.

3

Create the Person class and include the Greeter module

Create a class called Person and include the Greeter module inside it.

Ruby

module Greeter
  def greet
    "Hello!"
  end

  def self.included(base)
    puts "Greeter module included!"
  end
end

# Your code here

Need a hint?

Define the class with class Person and include the module using include Greeter.

4

Create a Person instance and print the greeting

Create an instance of Person called person. Then call person.greet and print the result.

Ruby

module Greeter
  def greet
    "Hello!"
  end

  def self.included(base)
    puts "Greeter module included!"
  end
end

class Person
  include Greeter
end

# Your code here

Need a hint?

Create the object with person = Person.new and print the greeting with puts person.greet.