gistfile1.rb

module ActiveRecord
  class Base
    def before_destroy
      associations_with_data.each { |assoc|
        errors.add(:assoc, "association has data")
      }
    end

    def associations_with_data
      associations_with_data = []
      self.class.reflect_on_all_associations.each { |assoc|
        associations_with_data << assoc.name if self.send(assoc.name).present?
      }
      return associations_with_data
    end
  end
end