ruby on rails - Accessing instance method from class method -

i have rails 4 app has alert model , tests associated each alert.

when new alert created have after_create filter uses instance method create new test:

class alert < activerecord::base     has_many :tests     after_create :create_test      private      def create_test      #bunch of code using external api data          test.create       end end 

i have cron job want use create new test each alert. plan have class method that:

def self.scheduled_test_creation         @alerts = alert.all         @alerts.each |a|           a.create_test                 end     end 

that won't work because instance method private. know can around using send example. or can make methods public. or can rewrite bunch of api code in instance method.

i not sure best way be. don't want write same code twice , want make sure practice. maybe in case methods don't have private - know difference between public/private/protected don't understand when methods should private/protected.

any appreciated

i service classes interactions between multiple models. callbacks can make logic quite hard follow.

eg:

class alertcreator   def initialize(alert)     @alert = alert   end    def call     if @alert.save       alert_test = testbuilder.new(@alert).call       alert_test.save       true     end   end end  class testbuilder   def initialize(alert)     @alert = alert   end    def call     # external api interaction stuff     # return unsaved test   end end 

inside controller, you'd call alertcreator.new(@alert).call instead of usual @alert.save.