The main feature i.e., Ordering API is added into API server. These endpoints provide the ability to work with the ordering system. This API is not simple like other as it checks for the discount codes and various other things as well.
The process in layman terms is very simple, first, a user must be registered or added as an attendee into Server without any order_id associated and then the attendee details will be sent to API server as a relationship.

Things needed to take care:

1. Validating the discount code and ensure it is not exhausted
2. Calculating the total amount on the server side by applying coupon
3. Do not calculate amount if the user is the event admin
4. Do not use coupon if user is event admin
5. Handling payment modes and generating payment links
6. Ensure that default status is always pending, unless the user is event admin

Creating Order

• • Prerequisite
    Before initiating the order, attendee records needs to be created associated with the event. These records will not have any order_id associated with them initially. The Order API will add the relationships.
  • Required Body
    Order API requires you to send event relationship and attendee records to create order_tickets
  • Permissions
    Only organizers can provide custom amount and status. Others users will get their status as pending and amount will be recalculated in server. The response will reflect the calculated amount and updated status.
    Also to initiate any order, user must be logged in. Guest can not create any order
  • Payment Modes
    There are three payment modes, free, stripe and paypal. If payment_mode is not provided then API will consider it as “free”.
  • Discount Codes
    Discount code can be sent as a relationship to the API. The Server will validate the code and will act accordingly.

Validating Discount Codes

Discount codes are checked to ensure they are valid, first check ensures that the user is not co-organizer

# Apply discount only if the user is not event admin
if data.get('discount') and not has_access('is_coorganizer', event_id=data['event']):

Second, check ensures that the discount code is active

if not discount_code.is_active:
  raise UnprocessableEntity({'source': 'discount_code_id'}, "Inactive Discount Code")

The third, Check ensures its validity is not expired

if not (valid_from <= now <= valid_till):
  raise UnprocessableEntity({'source': 'discount_code_id'}, "Inactive Discount Code")

Fourth Check ensure that the quantity is not exhausted

if not TicketingManager.match_discount_quantity(discount_code, data['ticket_holders']):
  raise UnprocessableEntity({'source': 'discount_code_id'}, 'Discount Usage Exceeded')

Lastly, the fifth check ensures that event id matches with given discount associated event

if discount_code.event.id != data['event'] and discount_code.user_for == TICKET:
  raise UnprocessableEntity({'source': 'discount_code_id'}, "Invalid Discount Code")

Calculating Order Amount

The next important thing is to recalculate the order amount and it will calculated only if user is not the event admin

if not has_access('is_coorganizer', **view_kwargs):
  TicketingManager.calculate_update_amount(order)

API Response

The API response apart from general fields will provide you the payment-url depending upon the payment mode you selected.

• Stripe : will give payment-url as stripe
• Paypal: will provide the payment completing url in payment-url

This all explains the flow and requirements to create an order. Order API consists of many more things related with TIcketing Manager which works to create the payment url and apply discount count as well as calculate the total order amount.

Resources

1. Stripe Payments API Docs
   https://stripe.com/docs/api
2. Paypal Payments API docs
   https://developer.paypal.com/docs/api/
3. Paypal Sandbox docs
   https://developer.paypal.com/docs/classic/lifecycle/ug_sandbox/