Ejemplo de como utilizar un Active Record Transaction

ActiveRecord_transaction.rb

  # Save scheduling distribution for a campaign
  def self.save_distribution params
    transaction_ok = true
    begin
      Scheduling.transaction do
        # Get campaign and company working week days
        campaign    = Campaign.find(params[:campaign][:id])
        company_wwd = campaign.company.working_week_days
        # Si no eligió ningún día laboral, se distribuye a cualquier día
        company_wwd = Hash[WORKING_WEEK_DAYS.collect { |wd| [wd, true] }] if company_wwd.values.uniq.length == 1 && !company_wwd.values.uniq.first
        # Create schedulings for visits for every visitor
        params[:visitors].each do |visitor|
          scheduling_date = campaign.date_start
          # Se recorre el listado de días a visitar
          visitor[:days].each do |day|
            day_found   = false
            days_count  = 0
            # Se cambia de día si el dia que se quiere visitar no es laboral y es feriado
            while !day_found && days_count < 7 do
              if company_wwd[scheduling_date.dayname] && !scheduling_date.is_holiday?(campaign.company_id)
                day_found       = true
                days_count      += 1
              else
                scheduling_date += 1.day
              end
            end
            # Se crean los schedulings para cada visita del día
            day[:visits].each do |visit|
              # visit_lat = visit[:location][:latitude] # ¿Qué hacer con esto?
              # visit_lng = visit[:location][:longitude] # ¿Qué hacer con esto?
              # visit_estimated_time_of_arrival = visit[:estimated_time_of_arrival] # ¿Qué hacer con esto?
              # visit_estimated_time_of_departure = visit[:estimated_time_of_departure] # ¿Qué hacer con esto?
              # Update scheduling
              visit_scheduling = Scheduling.find(visit[:id])

              if visit_scheduling.present?
                transaction_ok = false unless visit_scheduling.update(date: scheduling_date, source: 4)
              end
            end
            scheduling_date += 1.day
          end
        end
        # Change campaign status
        transaction_ok = false unless campaign.scheduled!
        # Force a rollback if transaction not ok
        unless transaction_ok
          campaign.magic_error!
          raise ActiveRecord::Rollback
        end
      end
    rescue => e
      CheckinLog.error_debug "ERROR CREATING SCHEDULINGS FOR CAMPAIGN #{campaign.id}: " + e.message
      transaction_ok = false
      Scheduling.destroy_visits_with_error(params[:visitors])
      campaign.magic_error!
      raise ActiveRecord::Rollback # Force a rollback if error was caught
    end

    #unassigned_visits = params[:unassigned_visits] # ¿Qué hacer con esto?

    transaction_ok # Return
  end