SimpleDecorator

simple-decorator -v
# => 0.2.0

SimpleDecorator allows you to quickly implement Decorators in your application.

A true decorator

SimpleDecorator decorators are true decorators :

• They delegate unknown methods to the underlying objects

  class User
    def foo
      'bar'
    end
  end
  
  class Decorator < SimpleDecorator
  
  end
  
  user_decorator = Decorator.new(User.new)
  user_decorator.foo
  # => 'bar'

• They can be stacked infinitely

    class User
      def initialize; @count = 1 end
  
      def count
        @count
      end
    end
  
    class CountDecorator < SimpleDecorator
     def count
       @component.count + 1
     end
    end
  
    class TripleCountDecorator < SimpleDecorator
      def count
        @component.count * 3
      end
    end
  
    user = User.new
    user.count
    # => 1
  
    CountDecorator.new(CountDecorator.new(user)).count
    # => 3
  
    TripleCountDecorator.new(CountDecorator.new(user)).count
    # => 6

• They are fully transparent

    class User; end
    class Decorator < SimpleDecorator; end
    class OtherDecorator < SimpleDecorator; end
  
    user = User.new
    decorator = Decorator.new(OtherDecorator.new(user))
    decorator.class
    # => User
    decorator.instance_of? User
    # => true
    decorator == user
    # => true

Installation

gem install simple-decorator

Usage

To create a decorator, simply inherit from SimpleDecorator.

  class Decorator < SimpleDecorator
  end

Then, you just need to wrap your object inside your Decorator class

  class Foobar; end
  # Decorator#new takes the instance you want to decorate as an argument
  Decorator.new(Foobar.new)

It will give you access to the following instance methods : source, decorated which will return decorated object.

Inside your Decorator class, you can access the decorated object through the instance variable @component

  class Foobar
    def foo
      'bar'
    end
  end

  class Decorator < SimpleDecorator
    def foo
      'foo' + @component.foo
    end
  end

  Decorator.new(Foobar.new).foo
  # => 'foobar'

Misc

'Licensed' under WTFPL