decorator.rb

module GoogleBackUp

def backup
  puts("Back Up with Google")
  super
end

end


module BoxBackUp

def backup
  puts("Back up with BOX ")
  super
end

end

class Phone

  def backup
    puts("Default backup stragegy")
  end

end


one_plus = Phone.new
one_plus.backup()
one_plus.extend(GoogleBackUp)
one_plus.backup()
one_plus.extend(BoxBackUp)
one_plus.backup()


module GoogleBackUp

def backup
  puts("Back Up with Google")
  super
end

end


module BoxBackUp

def backup
  puts("Back up with BOX ")
  super
end

end

class Phone

  def backup
    puts("Default backup stragegy")
  end

end


one_plus = Phone.new
one_plus.backup()
one_plus.extend(GoogleBackUp)
one_plus.backup()
one_plus.extend(BoxBackUp)
one_plus.backup()

=begin
Advantages:

The decorator pattern can be used to make it possible to extend (decorate) the functionality of a certain object at runtime.
The decorator pattern is an alternative to subclassing. Subclassing adds behavior at compile time, and the change affects all instances of the original class; decorating can provide new behavior at runtime for individual objects.
Decorator offers a pay-as-you-go approach to adding responsibilities. Instead of trying to support all foreseeable features in a complex, customizable class, you can define a simple class and add functionality incrementally with Decorator objects.


Disadvantages:

Decorators can complicate the process of instantiating the component because you not only have to instantiate the component, but wrap it in a number of decorators.
It can be complicated to have decorators keep track of other decorators, because to look back into multiple layers of the decorator chain starts to push the decorator pattern beyond its true intent.
=end