What is the Transaction class which your model inherits from ? Is it just a base model ?
Let’s do an experiment Print(“object created”) right after the create() method Print(“callback requested”) on top of your callback method Which one do you see first ? Sent from my iPhone > On 21 Aug 2019, at 16:56, Ahmed Shahwan <[email protected]> wrote: > > That's the class, nothing different other than HTTP requests > > class CashPayment(BasePayment): > """Cash Payment Wrapper Class""" > > integration_id = CASH_INTEGRATION_ID > > def __init__(self, amount_cents: int, billing_data: dict): > super().__init__(amount_cents, billing_data) > > def pay_request(self): > """Step 4. issue Pay request""" > payload = { > "source": {"identifier": "cash", "subtype": "CASH"}, > "payment_token": self.payment_key_res.get("token"), > } > self.pay_req_res = self.hit_accept( > self._api_url + "acceptance/payments/pay", payload=payload > ) > > >> On Wednesday, August 21, 2019 at 3:39:13 PM UTC+2, mohamed habib wrote: >> if you are able to share more code from the `utils.CashPayment` call that >> may help us >> >>> On Wed, Aug 21, 2019 at 4:37 PM mohamed habib <[email protected]> wrote: >>> I highly doubt its related to ORM or postgres, the creation of the record >>> is synchronous so you can be sure that the record exists after the create() >>> call. >>> >>> Since you are sure that you are fetching the data properly we can rule out >>> this possibility >>> >>> Its probably a race condition of the callback arriving too soon *before* >>> you hit the create() call. So do you know at what point your payment >>> gateway will make the callback request and what would trigger it? Make sure >>> you are >>> >>>> On Wed, Aug 21, 2019 at 4:19 PM Ahmed Shahwan <[email protected]> wrote: >>>> I tried, same happened. it's related to how Postgres works internally with >>>> the Django-ORM. >>>> >>>>> On Wednesday, August 21, 2019 at 3:07:47 PM UTC+2, mohamed habib wrote: >>>>> Wild guess in the dark here, as I am unfamiliar with this API. you are >>>>> doing: >>>>> >>>>> `payment.pay_request()` >>>>> >>>>> before creating the WeacceptTransaction object. >>>>> >>>>> Maybe this line needs to move below: >>>>> `models.WeAcceptTransaction.objects.create(...)` ? >>>>> >>>>> At what point is the callback request triggered ? >>>>> >>>>>> On Wed, Aug 21, 2019 at 3:36 PM Ahmed Shahwan <[email protected]> wrote: >>>>>> Transaction model: >>>>>> >>>>>> >>>>>> class WeacceptTransaction(Transaction): >>>>>> """Weaccept's Transaction model""" >>>>>> >>>>>> # before frontend interaction >>>>>> auth_token = models.TextField() # got from step 1 >>>>>> order_id = models.IntegerField(verbose_name="Accept's Order ID") # >>>>>> id from step 2 >>>>>> order_url = models.CharField(max_length=255, null=True) # order_url >>>>>> from step 2 >>>>>> billing_data = JSONField() # provided in request for paymet key, >>>>>> step 3 >>>>>> payment_key = models.TextField() # payment_token from step 3 >>>>>> hmac = models.TextField(null=True) >>>>>> # after (from callback) >>>>>> success_status = models.BooleanField(default=False) >>>>>> is_refunded = models.BooleanField(default=False) >>>>>> reference_number = models.IntegerField(null=True) >>>>>> processed_clbk_json = JSONField(null=True) >>>>>> >>>>>> >>>>>> The cash_payment View: >>>>>> >>>>>> class CashPayment(APIView): >>>>>> """Cash Payment endpoint""" >>>>>> >>>>>> serializer_class = serializers.CardPaymentSerializer >>>>>> required_fields = ["amount_cents", "billing_data"] >>>>>> >>>>>> def post(self, request): >>>>>> # Validate required fields >>>>>> utils.validate(self.required_fields, request) >>>>>> payment = utils.CashPayment(**request.data) >>>>>> payment.prepare() >>>>>> payment.pay_request() >>>>>> # create a new transaction >>>>>> models.WeacceptTransaction.objects.create( >>>>>> merchant_order_id=payment.merchant_order_id, >>>>>> amount=payment.amount_cents, >>>>>> auth_token=payment.auth_res.get("token"), >>>>>> order_id=payment.order_reg_res.get("id"), >>>>>> order_url=payment.order_reg_res.get("order_url"), >>>>>> billing_data=payment.billing_data, >>>>>> payment_key=payment.payment_key_res.get("token"), >>>>>> hmac=payment.pay_req_res.get("hmac"), >>>>>> ) >>>>>> >>>>>> return Response( >>>>>> { >>>>>> "message": "Our representative will go to the address >>>>>> you provided " >>>>>> "to collect the cash from you", >>>>>> **payment.pay_req_res, >>>>>> } >>>>>> ) >>>>>> >>>>>> >>>>>> Please note: the first 3 steps are wrapped into the method `prepare()` >>>>>> the 4th step is `pay_request()` >>>>>> >>>>>> >>>>>> the callback-url endpoint (where the 5th step happens) >>>>>> >>>>>> class TransactionProcessedCallback(APIView): >>>>>> """Processed callback that will recieve "TRANSACTION", "TOKEN", >>>>>> "ORDER", >>>>>> "DELIVERY_STATUS" objects""" >>>>>> >>>>>> def post(self, request): >>>>>> # XXX extend to handle TOKEN, DELIVERY_STATUS objects... later >>>>>> t_obj = request.data.get("obj") # transaction object >>>>>> incoming_hmac = request.query_params.get("hmac") >>>>>> calculated_hmac = utils.calculate_hmac_transaction(t_obj) >>>>>> >>>>>> # if not equal hmac, not coming from Accept! >>>>>> if incoming_hmac != calculated_hmac: >>>>>> return Response( >>>>>> {"message": "invalid data"}, >>>>>> status=status.HTTP_400_BAD_REQUEST >>>>>> ) >>>>>> >>>>>> import ipdb >>>>>> >>>>>> ipdb.set_trace() >>>>>> # XXX: The error happens here >>>>>> transaction = models.WeacceptTransaction.objects.get( >>>>>> merchant_order_id=t_obj.get("order").get("merchant_order_id") >>>>>> ) >>>>>> transaction.success_status = bool(t_obj.get("success")) >>>>>> transaction.is_refunded = bool(t_obj.get("is_refunded")) >>>>>> transaction.reference_number = >>>>>> int(t_obj.get("data").get("transaction_no") or 1) >>>>>> transaction.processed_clbk_json = t_obj >>>>>> transaction.save( >>>>>> update_fields=[ >>>>>> "success_status", >>>>>> "is_refunded", >>>>>> "reference_number", >>>>>> "processed_clbk_json", >>>>>> ] >>>>>> ) >>>>>> >>>>>> email = t_obj.get("order").get("shipping_data").get("email") >>>>>> # TODO: send mail based upon success status >>>>>> try: >>>>>> send_mail( >>>>>> "Transaction Processed", >>>>>> "Your transaction is processed", >>>>>> "SERNDER MAIL", >>>>>> [email], >>>>>> fail_silently=False, >>>>>> ) >>>>>> except Exception as ex: >>>>>> print(">>>>>>>>>>FAILED TO SEND MAIL") >>>>>> print(ex) >>>>>> >>>>>> return Response({"message": "Transaction Updated!"}, >>>>>> status=status.HTTP_200_OK) >>>>>> >>>>>> >>>>>> The 6th step (redirect-url) is irrelevant here, and not included in the >>>>>> XPAY's service for this payment option. >>>>>> >>>>>> >>>>>>> On Wednesday, August 21, 2019 at 2:03:20 PM UTC+2, mohammed habib wrote: >>>>>>> Are you sure the callback request passes the right parameters ? >>>>>>> >>>>>>> Could you share some of your views code from the 6 steps, and your >>>>>>> Transaction model ? >>>>>>> >>>>>>> Sent from my iPhone >>>>>>> >>>>>>>> On 21 Aug 2019, at 14:46, Ahmed Shahwan <[email protected]> wrote: >>>>>>>> >>>>>>>> Hi, >>>>>>>> >>>>>>>> I have a very strange problem that I don't know why it happens. >>>>>>>> I'm creating a REST API service that wraps another REST API payment >>>>>>>> service, let's call the other services XPAY. It has various payment >>>>>>>> options (Card, eWallet, Kiosk, and Cash). The steps required to use >>>>>>>> the services (to make a transaction) >>>>>>>> >>>>>>>> 1. authentication 2. order registration 3. payment key 4. prepare >>>>>>>> frontend based on payment type 5. Callback URL 6. Redirect URL >>>>>>>> >>>>>>>> and each step depends on its predecessor. The first 4 steps are >>>>>>>> performed through HTTP Requests that I issue from my service. I store >>>>>>>> some of the information I receive in those steps in a Model called >>>>>>>> Transaction. 5th and 6th steps are Callback endpoints that I create to >>>>>>>> receive further information about the status of the transaction that I >>>>>>>> started in the first 4 steps. >>>>>>>> >>>>>>>> My endpoints design is: >>>>>>>> >>>>>>>> myservice/payment/card >>>>>>>> myservice/payment/wallet >>>>>>>> myservice/payment/kiosk >>>>>>>> myservice/payment/cash >>>>>>>> >>>>>>>> myservice/payment/callback-url >>>>>>>> myservice/payment/redirect-url >>>>>>>> >>>>>>>> These endpoints are wrappers for the payment methods available in >>>>>>>> XPAY's service that my frontend apps will use to provide those payment >>>>>>>> options for users. >>>>>>>> >>>>>>>> I implemented the first 3 endpoints with no problem. inside those >>>>>>>> endpoints, I create a transaction object with a unique id and then >>>>>>>> update it from inside the callback-url endpoint after I receive the >>>>>>>> information from XPAY's service. Note that it takes some time between >>>>>>>> creating the Transaction object and saving it into the database from >>>>>>>> inside my endpoint, and updating it from inside the callback url >>>>>>>> endpoint. >>>>>>>> >>>>>>>> The weird thing happens in the 4th endpoint `cash` endpoint. XPAY's >>>>>>>> service responds very quickly on my callback-url endpoint and when it >>>>>>>> gets to the updating step, I get Transaction.DoesNotExist Exception >>>>>>>> while getting the transaction object using >>>>>>>> Transaction.objects.get(id=id). >>>>>>>> >>>>>>>> After some debugging time using ipdb I found that the instance has >>>>>>>> already been saved to the database! and I can retrieve it with its id. >>>>>>>> but when I let it run ordinarily the saving operation doesn't finish >>>>>>>> until that time (I got to know that using some print() statements), >>>>>>>> which is very strange, it's impossible that my laptop is that slow! >>>>>>>> >>>>>>>> Solutions I tried: >>>>>>>> 1. atomic transaction >>>>>>>> 2. time.sleep some time after making the request and saving the >>>>>>>> transaction object to the db >>>>>>>> 3. time.sleep in the callback-url before getting the transaction from >>>>>>>> DB >>>>>>>> >>>>>>>> I checked any possible logic error related to it and there's nothing >>>>>>>> illogical. >>>>>>>> >>>>>>>> the issue is related to Postgres and how it operates, and also with >>>>>>>> Django's ORM. I don't know. >>>>>>>> >>>>>>>> Main technologies I use: >>>>>>>> Django 2.2 >>>>>>>> Postgres Docker container >>>>>>>> DRF >>>>>>>> >>>>>>>> I hope someone gives me an insight into why this is happening and how >>>>>>>> to work around it. >>>>>>>> >>>>>>>> Thanks >>>>>>>> -- >>>>>>>> You received this message because you are subscribed to the Google >>>>>>>> Groups "Django users" group. >>>>>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>>>>> an email to [email protected]. >>>>>>>> To view this discussion on the web visit >>>>>>>> https://groups.google.com/d/msgid/django-users/e43be322-bab9-4162-9fbc-05c6c9b95c94%40googlegroups.com. >>>>>> >>>>>> -- >>>>>> You received this message because you are subscribed to the Google >>>>>> Groups "Django users" group. >>>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>>> an email to [email protected]. >>>>>> To view this discussion on the web visit >>>>>> https://groups.google.com/d/msgid/django-users/a379e013-a01c-4c58-bf2b-0b4cd01f0fae%40googlegroups.com. >>>>> >>>>> >>>>> -- >>>>> Best regards, >>>>> Mohammed M. Habib, PhD >>>>> >>>> >>>> -- >>>> You received this message because you are subscribed to the Google Groups >>>> "Django users" group. >>>> To unsubscribe from this group and stop receiving emails from it, send an >>>> email to [email protected]. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/django-users/987c6ce7-70b6-49a9-ab3e-506e369d060e%40googlegroups.com. >>> >>> >>> -- >>> Best regards, >>> Mohammed M. Habib, PhD >>> >> >> >> -- >> Best regards, >> Mohammed M. Habib, PhD >> > > -- > You received this message because you are subscribed to the Google Groups > "Django users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/django-users/044d543f-5b6e-40d7-9ee6-36b7e84f5647%40googlegroups.com. -- You received this message because you are subscribed to the Google Groups "Django users" group. 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