Examples of low level caching

application_controller.rb

class ApplicationController < ActionController::Base
  protect_from_forgery
  before_filter do
    @categories = Rails.cache.fetch("global/categories", expires_in: 10.minutes) do
      Category.where("posts_count > 0").all
    end
  end
end

place.rb

class Place < ActiveRecord::Base
  def flickr_place
    flickr = FlickRaw::Flickr.new
    @flickr_place ||= Rails.cache.fetch("places/#{id}-#{updated_at}/flickr/place_id", expires_in: 7.days) do
      if latitude? && longitude?
        begin
          places = flickr.places.findByLatLon(lat: latitude, lon: longitude)
          places.try(:first)
        rescue Exception => e
          logger.info "Exception occurred fetching Flickr place ID: #{e.to_s}"
          nil
        end
      end
    end
  end
end