kaminariでページネートオブジェクトだけが欲しいときに

kaminari_simple_paginatable.rb

module Kaminari
  class SimplePaginatable
    DEFAULTS = {
      :total_count => 0,
    }
    include Kaminari::ConfigurationMethods::ClassMethods

    attr_internal_accessor :limit_value, :offset_value

    def initialize(options, limit_val = default_per_page, offset_val = 0) #:nodoc:
      @_options, @_limit_value, @_offset_value = options, limit_val, offset_val
    end

    def page(num = 1)
      offset(limit_value * ([num.to_i, 1].max - 1))
    end

    def limit(num)
      self.class.new @_options, num, offset_value
    end

    def total_count
      @_options[:total_count]
    end

    def offset(num)
      obj = self.class.new @_options, limit_value, num
      class << obj
        include Kaminari::PageScopeMethods
      end
      obj
    end
  end

  def self.create_pagination(options)
    SimplePaginatable.new SimplePaginatable::DEFAULTS.merge(options)
  end
end