Question

I am writing a reservation API and I want to create temporary holds on assets while a user goes through the booking app. So basically, I need a way to create temporary records in my DB that expire after a certain time period has passed. Any ideas on how I should do that?

Answer 1

class Reservation < ActiveRecord::Base
  def reservation_has_ended
    Time.now > reservation_datetime
  end
  # or...
  def reservation_is_open
    Time.now < reservation_datetime
  end
  # similarly...
  scope is_open where(Time.now > reservation_datetime)
  scope has_ended where(Time.now < reservation_datetime)
  # ... but remember scopes are going away in rails 4.1...
end

I would then have a cron job that, say hour or daily,
cleans up all records > 1 hour (or other period) old.

You could also make it a manual job, trigger from a view link with an update action in the controller and model, say,

# Reservation View
<%= link_to("Purge records", Reservation.purge) %>

# Reservation Controller
def remove_old_reservations
  Reservation.remove_old_reservations
end 

# Reservation Model:
def remove_old_reservations
  self.delete_all.where((Time.now - 1.hour) > reservation_datetime)
end