Salom，我是Charlie！

在Day20的時候我們完成了createOrder跟CaptureOrder的Client，今天我們將把後端的結帳跟兩個Client結合在一起。

================================◉‿◉=================================

首先是創立訂單的部分，先在userorder當中建立在創立訂單時，使用createOrderClient建立paypal金流的部分：

try:
	paypalresponse = CreateOrder().create_order(CURRENCY_CODE,totalvalue)
except Exception as e:
	return R.internalServerError(str(e))
else:
	data = fromPaypalResponse(paypalresponse)
	return R.ok(data)

因為paypalResponse不是json data所接受的格式，所以在下面建立fromPaypalResponse的方法：

def fromPaypalResponse(response):
	data = {}
	data["code"] = response.status_code
	data["status"] = response.result.status
	data["orderid"] = response.result.id
	data["intent"] = response.result.intent
	data["links"] = {}
	for link in response.result.links:
		data["links"][link.rel] = link.href
	data["total_Amount"] = response.result.purchase_units[0].amount.value
	return data

接著使用POSTMAN測試：

再來是captureOrder的部分，先建立url的部分：

url(r'/capture/(?P<orderID>[\w+]{1,55})$',views.captureOrder),

接著在views當中建立captureOrder方法，使用CaptureOrderClient來收款：

@logincheck('POST')
def captureOrder(request,orderID = None):
	if not orderID:
		return R.badRequest("order id does not exist")
	if request.method == "POST":
		try:
			response = CaptureOrder().capture_order(orderID)
		except Exception as e:
			return R.internalServerError(str(e))
		else:
			return R.ok(fromCaptureResponse(response))
	else:
		return R.methodNotAllowed("method not allowed")

接著建立fromCaptureResponse方法，把capture傳回的結果化為json：

def fromCaptureResponse(response):
	data = {}
	data["code"] = response.status_code
	data["status"] = response.result.status
	data["orderid"] = response.result.id
	data["links"] = {}
	for link in response.result.links:
		data["links"][link.rel] = link.href
	data["capture"] = []
	for purchase_unit in response.result.purchase_units:
		for capture in purchase_unit.payments.captures:
			data["capture"].append(capture.id)
	return data

測試，如果已經capture過的話會出現錯誤，如果第一次capture則會正常：

接著我們還要做一件事情：將paypal order id加入我們的資料庫。

如果用戶尚未付款的話，在訂單詳情頁面一樣能按下付款，同時，如果capture過了，必須要記錄訂單狀態為paid。

所以我們先在models裡面建立新欄位：

class Order(models.Model):
	id = models.AutoField(primary_key = True)
	orderno = models.CharField(max_length = 255,verbose_name = "訂單編號")
	product = models.ForeignKey(Product,on_delete = models.CASCADE)
	user = models.ForeignKey(User,on_delete = models.CASCADE)
	amount = models.IntegerField(verbose_name = "商品數量")
	status = models.IntegerField(verbose_name = "狀態")
	paypal_id = models.CharField(max_length = 255,verbose_name = "paypal訂單編號")
	created_time = models.DateTimeField(auto_now = True)
	modified_time = models.DateTimeField(auto_now = True)

	class Meta:
		db_table = "orders"

並且執行遷移：

$ python manage.py makemigrations userorder
$ python manage.py migrate userorder

接著我們修改createOrder的程式碼，創建paypal訂單後把cart狀態設為deactivate，並且儲存order item：

totalvalue = 0
for cart in usercart:
	totalvalue += cart.amount * cart.product.price
try:
	paypalresponse = CreateOrder().create_order(CURRENCY_CODE,totalvalue)
except Exception as e:
	return R.internalServerError(str(e))
else:
	data = fromPaypalResponse(paypalresponse)
	paypal_id = data["orderid"]
	for cart in usercart:
		cart.status = CartStatus.deactivate.value
		cart.save()
		userorder = Order.objects.create(
			orderno = orderno,
			product = cart.product,
			user = cart.user,
			amount = cart.amount,
			status = OrderStatus.notPaid.value,
			paypal_id = paypal_id
		)		
	return R.ok(data)

接著到captureOrder，加上改變訂單狀態的程式碼：

if request.method == "POST":
	try:
		response = CaptureOrder().capture_order(orderID)
	except Exception as e:
		return R.internalServerError(str(e))
	else:
		orders = Order.objects.filter(paypal_id = orderID)
		for order in orders:
			order.status = OrderStatus.paid.value
			order.save()
		return R.ok(fromCaptureResponse(response))

測試：

如此，我們就先完成了後端的結帳部分。

================================◉‿◉=================================

Day21結束了！在今天我們完成了paypal跟後端交互的部分，而明天我們將完成前端的結帳結合Paypal的部分，See ya next day！