bigevilempire

 

Using Ruby Modules

In my recent pursue of learning Rails, I have gotten more exposure to the Ruby. The Ruby programming language is very pretty in terms of its syntax and the semantics. It is object-oriented and allow classes to import modules as mixins, which is the subject of this post.

I am still very new to Ruby and pretty much learning as I go along. This post is more to document my own learning than anything. 

module MySharedModule
  HASH_CONSTANT = {:mykey => "value of mykey"}
  
  def mixin_method
    puts "calling mixin method"
  end
    
  class ClassInModule
    def self.class_method
      puts "calling class method"
    end
    
    def instance_method
      puts "calling instance_method"
    end
  end
end


class MyClass
  include MySharedModule
  
  def initialize
    # access module's constant
    # to be more verbose: MySharedModule::HASH_CONSTANT 
    puts HASH_CONSTANT[:mykey]    
    
    # access module method
    mixin_method
        
    # calls class method of a class in module
    # to be more verbose: MySharedModule::ClassInModule.class_method
    ClassInModule.class_method
        
    # instantiate, call instance method of class in module
    # to be more verbose: MySharedModule::ClassInModule.class_method
    instance = ClassInModule.new
    instance.instance_method    
  end
end


myClass = MyClass.new



# Output:
# value of mykey
# calling mixin method
# calling class method
# calling instance_method

To learn more about using modules in Ruby: