从3个不同型号中接收PayPal ipn的正确方法是什么?

Question

我使用Django-Paypal接收3种不同服务的付款。每个服务都有一个独立的模型(比如ServiceA、ServiceB和ServiceC)，但它们都在同一个应用程序中。我需要在收到相应服务的付款后，将正确模型的付款状态更新为"paid=True"。

我有3个支付处理视图(每个服务)工作良好，因为所有支付都成功完成。同样，我创建了3个信号/接收器函数(每个模型)并将它们放在signals.py中。当我一次测试一个信号时，它工作得很好。付款状态成功更新为"paid=True"。但是，当我在signals.py中包含所有三个信号时，事情就停止工作了。我注意到每次收到付款时，前两个接收函数都会被触发，从而导致错误。查看底部的代码

当从特定模型收到付款时，我如何指定应该调用哪个接收函数?或者哪一种是成功实现上述目标的最佳方式?当我使用预保存等内置信号时，可以通过在装饰器中添加发送者来指定要更新的模型，例如

@receiver(pre-save, sender = MyModel)

关于PayPal的IPN信号，我完全卡住了，欢迎任何帮助，包括想法。提前谢谢。

@receiver(valid_ipn_received)
def Servicea_order_item_paid(sender, **kwargs):
ipn_obj = sender
if ipn_obj.payment_status == ST_PP_COMPLETED:
servicea = ServiceA.objects.get(order_id =ipn_obj.invoice)
if (
ipn_obj.mc_gross == servicea.total_cost() 
and ipn_obj.mc_currency == 'USD' 
and ipn_obj.receiver_email == "[e-mail]"
):
servicea.paid = True
servicea.save()
@receiver(valid_ipn_received)
def serviceb_order_item_paid(sender, **kwargs):
ipn_obj = sender
if ipn_obj.payment_status == ST_PP_COMPLETED:
serviceb = ServiceB.objects.get(order_id =ipn_obj.invoice)
if (
ipn_obj.mc_gross == serviceb.total_cost() 
and ipn_obj.mc_currency == 'USD' 
and ipn_obj.receiver_email == "[e-mail]"
):
serviceb.paid = True
serviceb.save()
@receiver(valid_ipn_received)
def servicec_order_item_paid(sender, **kwargs):
ipn_obj = sender
if ipn_obj.payment_status == ST_PP_COMPLETED:
servicec = ServiceC.objects.get(order_id =ipn_obj.invoice)
if (
ipn_obj.mc_gross == servicec.total_cost() 
and ipn_obj.mc_currency == 'USD' 
and ipn_obj.receiver_email == "[e-mail]"
):
servicec.paid = True
servicec.save()

Answer 1

虽然我在这里无法得到答案，但我最终解决了这个问题。我将三个信号组合成一个单一的"复合"信号，使用:

<<ul>

过滤器/gh>

if指令和

exists()方法

最后的代码很长，但它运行良好，没有任何错误。甚至'Duplicate txn_id'错误也最终消失了。为了共享代码，我分别用ServiceA、B和C代替了实际的服务。请看下面的代码:

@receiver(valid_ipn_received)
def order_item_paid(sender, **kwargs):
ipn_obj = sender
if ipn_obj.payment_status == ST_PP_COMPLETED:
print('Payment was sucessful!!!!, pending other verifications')
if ServiceA.objects.filter(order_id =ipn_obj.invoice).exists():
print('!!!! ServiceA Oder object exists')
servicea = get_object_or_404(ServiceA, order_id =ipn_obj.invoice)

if (
ipn_obj.mc_gross == servicea.total_cost() 
and ipn_obj.mc_currency == 'USD' 
and ipn_obj.receiver_email == "[e-mail]"
):
print('!!!. Amount, Currency and Email Verified')
servicea.paid = True
servicea.save()
else:
print('!!!! ServiceA order item does not exist')
if ServiceB.objects.filter(order_id =ipn_obj.invoice).exists():
print('!!!! ServiceB order item exists')
serviceb = get_object_or_404(ServiceB, order_id =ipn_obj.invoice)

if (
ipn_obj.mc_gross == serviceb.total_cost() 
and ipn_obj.mc_currency == 'USD' 
and ipn_obj.receiver_email == "[e-mail]"
):
print('!!!!!!. Amount, Currency and Email Verified')
serviceb.paid = True
serviceb.save()
else:
print('!!!!!!!!Service B Order object does not exist')

if ServiceC.objects.filter(order_id =ipn_obj.invoice).exists():
print('!!!!!!!!Service C order item exists')
servicec = get_object_or_404(ServiceC, order_id =ipn_obj.invoice)

if (
ipn_obj.mc_gross == servicec.total_cost() 
and ipn_obj.mc_currency == 'USD' 
and ipn_obj.receiver_email == "[e-mail]"
):
print('!!!!!!. Amount, Currency and Email Verified')
servicec.paid = True
servicec.save()

else:
print('!!! Service C order object does not exist')