Handle cache inconsistency by clearing affected models. Allow use of counter caches.

cash_money_extensions.rb

# include Cash::Extensions after you declare is_cached for a class

module Cash
  module Extensions
    def self.included(base)    
      base.send(:extend,  ClassMethods)
      base.send(:include, InstanceMethods)
    end

    module ClassMethods
      # Counter caches aren't needed with cache-money since you can cache the actual count queries but
      # use this hack if you want to use counter caches anyway.
      def update_counters_with_cache_expire(id, counters)
        update_counters_without_cache_expire(id, counters)
        find(id).expire_caches
      end
      
      def self.extended(base)
        class << base
          alias_method_chain :update_counters, :cache_expire 
        end
      end
    end

    module InstanceMethods
      def save_with_cache_expire(*args)
        save_without_cache_expire(*args)
      rescue ActiveRecord::StaleObjectError => e
        expire_caches
        raise e
      end
      
      def save_with_cache_expire!(*args)
        save_without_cache_expire!(*args)
      rescue ActiveRecord::StaleObjectError => e
        expire_caches
        raise e
      end
      
      def self.included(base)
        base.alias_method_chain :save, :cache_expire
        base.alias_method_chain :save!, :cache_expire
      end
    end
  end
end