Simple Collection Decorator that plays nice with Kaminari

decorator.rb

class BaseDecorator
  def initialize(source)
    @source = source
  end

  def method_missing(method_key, *args, &block)
    @source.send(method_key, *args, &block)
  end

  def respond_to_missing?(method_key, *args, &block)
    @source.respond_to?(method_key, *args, &block)
  end
end

class BaseDecorator::Collection
  attr_accessor :source

  array_methods = Array.instance_methods - Object.instance_methods
  delegate :==, :as_json, *array_methods, to: :decorated_collection
  delegate :current_page, :total_pages, :limit_value, to: :source

  def initialize(source, page=nil)
    @source = source.page(page)
  end

  def decorated_collection
    @decorated_collection ||= source.map { |item| item_decorator(item).new(item) }
  end
  
  def item_decorator(obj)
    "#{obj.class.name}Decorator".constantize
  end
end