kaminari--kaminari/lib/kaminari/models/page_scope_methods.rb

module Kaminari
  module PageScopeMethods
    extend ActiveSupport::Concern
    module InstanceMethods
      # Specify the <tt>per_page</tt> value for the preceding <tt>page</tt> scope
      #   Model.page(3).per(10)
      def per(num)
        if (n = num.to_i) <= 0
          self
        else
          limit(n).offset(offset_value / limit_value * n)
        end
      end

      # Total number of pages
      def num_pages
        (total_count.to_f / limit_value).ceil
      end

      # Current page number
      def current_page
        (offset_value / limit_value) + 1
      end

      # First page of the collection ?
      def first_page?
        current_page == 1
      end

      # Last page of the collection?
      def last_page?
        current_page >= num_pages
      end
    end
  end
end