class_eval in active record callback

my_model.rb

        
  after_save do |my_model|                                                                                                                 
    self.class_eval do
      # my_model.job_owner_type => "AnotherModel"                                                                                       
      alias_method my_model.job_owner_type.underscore.to_sym, :job_owner                                                                   
    end                                                                                                                                                                                                  
  end