example.rb

class Location
  include SamyRoad::Redis::Objects
  
  has_counter: :24_hours
  
end

# You can access to the counter's value directly like
#   location.24_hours_count

pharmacies_observer.rb

class PharmacyObserver < ActiveRecord::Observer
def after_create(pharmacy)
    pharmacy.location.24_hours_counter.increment
  end

  def after_destroy(model)
    pharmacy.location.24_hours_counter.decrement
  end
end

redis-counter.rb

module Sanitas
  module Redis
    module Objects

      def self.included(klass)
        klass.send(:include, Redis::Objects)
        klass.extend(ClassMethods)
      end

      module ClassMethods

        def has_counter(name, options = {})
          counter_name  = name.to_s + "_counter"
          method_name   = name.to_s + "_count"
          counter(counter_name, options)

          define_method method_name do
            send(counter_name).value
          end

        end
      end
    end
  end
end