Method_added hook in Ruby - Mini Project: Build & Apply

Using the Method_added Hook in Ruby

📖 Scenario: Imagine you are creating a Ruby class that needs to keep track of every new method added to it. This can be useful for debugging or logging purposes.

🎯 Goal: You will build a Ruby class that uses the method_added hook to print the name of each method as it is defined.

📋 What You'll Learn

Create a class called Tracker

Define the method_added hook inside the Tracker class

Add at least two instance methods to the Tracker class

Print the name of each method when it is added using method_added

💡 Why This Matters

🌍 Real World

Tracking method definitions helps developers debug code and understand how classes evolve during runtime.

💼 Career

Knowing Ruby hooks like method_added is useful for Ruby developers working on metaprogramming, frameworks, or debugging tools.

1

Create the Tracker class

Create a class called Tracker with no methods inside it.

Ruby

class Tracker
  # Your code here
end

Need a hint?

Use the class keyword followed by Tracker and end to define the class.

2

Add the method_added hook

Inside the Tracker class, define method_added that takes one parameter called method_name. Inside this method, print the text "Method added: #{method_name}" using puts.

Ruby

class Tracker
  # Define the method_added hook here
  # Your code here
end

Need a hint?

The method_added hook is a method that receives the name of the method just added as a symbol.

3

Add instance methods to Tracker

Add two instance methods inside the Tracker class: hello and goodbye. Each method should just have an empty body.

Ruby

class Tracker
  def self.method_added(method_name)
    puts "Method added: #{method_name}"
  end

  # Add instance methods hello and goodbye below
  # Your code here
end

Need a hint?

Define instance methods with def method_name and end.

4

Run the class to see method_added output

Run the Ruby code to see the output from the method_added hook printing the names of the methods hello and goodbye.

Ruby

class Tracker
  def self.method_added(method_name)
    puts "Method added: #{method_name}"
  end

  def hello
  end

  def goodbye
  end
end

# Run the code to see output
# Your code here

Need a hint?

Just running this code will automatically call method_added when the methods are defined.