我在Ubuntu 12.04上使用Django 1.4和Python 2.7。
我有一个从表单帖子获取信息的视图。它首先要做的是尝试根据表单中给出的信息找到客户信息。
在测试时，我正在提供虚假信息，而且似乎没问题。我希望它抛出一个DoesNotExist异常，然后我调用原始视图再次向用户显示该表单。我可以不这样做吗？
以下是两种观点：
def input_new_client(request):
"""
.. function:: input_new_client()
Add the client based on the addClientInfo form
:param request: Django Request object
"""
## Create a logging object
path = os.path.join(os.path.dirname(__file__), 'logs/')
filename = '{0}inputNewClient.log'.format(path)
logfile = open(filename, 'w')
now = datetime.datetime.now()
logfile.write('\n --------------------- {0}\n'.format(now))
if (request.method == "POST"):
tkz_ys_api_id = request.POST.get("tkz_ys_api_id")
tkz_ys_trans_key = request.POST.get("tkz_ys_trans_key")
## Validate the YS authentication information
try:
clientInfo = ClientInfo.objects.get(tkz_api_id = tkz_ys_api_id, tkz_trans_key = tkz_ys_trans_key)
except ClientInfo.DoesNotExist or ClientInfo.MultipleObjectsReturned:
logfile.write('{0}\n\n'.format(tkz_ys_api_id))
logfile.write('{0}\n\n'.format(tkz_ys_trans_key))
logfile.write('{0}\n\n'.format(traceback.format_exc()))
logfile.close()
state = "Invalid YS Authentication! Please try again."
add_new_client(request, state)
else:
if (clientInfo.name != "Your Solutions"):
state = "Invalid YS Authentication! Please try again."
add_new_client(request, state)
## Generate a Tokeniz API ID and Trans Key for the new client
(tkz_api_id, tkz_trans_key) = generate_credentials()
## Create a new client
new_client = ClientInfo(name = request.POST.get("tkz_client_name"),
tkz_api_id = tkz_api_id,
tkz_trans_key = tkz_trans_key,
default_gateway_id = request.POST.get("tkz_gateway")
)
new_client.save()
## Validate the YS authentication information
try:
clientInfo = ClientInfo.objects.get(tkz_api_id = tkz_api_id, tkz_trans_key = tkz_trans_key)
foriegn_key = clientInfo.id
except ClientInfo.DoesNotExist or ClientInfo.MultipleObjectsReturned:
output = "Invalid YS Authentication! Please try again."
logfile.write('\n{0}\n'.format(output))
logfile.write('{0}\n\n'.format(traceback.format_exc()))
logfile.close()
## Setup the new clients gateway information
new_gateway_info = GatewayInfo(client = foriegn_key,
api_id = request.POST.get("tkz_gateway_api_id"),
trans_key = request.POST.get("tkz_gateway_trans_key"),
gateway_id = request.POST.get("tkz_gateway"),
)
new_gateway_info.save()
data = {}
data.update(csrf(request))
data.update({ 'tkz_api_id' : tkz_api_id })
data.update({ 'tkz_trans_key' : tkz_trans_key })
data.update({ 'client_name' : request.POST.get("tkz_client_name")})
return render_to_response("updatedClientCredentials.html", data)
显示表单的原始视图：
def add_new_client(request, state = None):
"""
.. function:: add_new_client()
Provide a form for entering new client information
:param request: Django Request object
:param state: A message representing the state of the addition of a client
"""
## Create a logging object
path = os.path.join(os.path.dirname(__file__), 'logs/')
filename = '{0}addNewClient.log'.format(path)
logfile = open(filename, 'a')
now = datetime.datetime.now()
logfile.write('\n --------------------- {0}\n'.format(now))
if (state is None):
state = "Enter information for adding a new client to Tokeniz."
try:
form = AddClientInfo()
except:
output = "Handle Error: Cannot create a valid form"
logfile.write('{0}\n'.format(output))
logfile.write('{0}\n\n'.format(traceback.format_exc()))
logfile.close()
return HttpResponse(output)
try:
data = {}
data.update(csrf(request))
data.update({ 'form' : form })
data.update({ 'state' : state })
except:
output = "Handle Error: Cannot generate CSRF token"
logfile.write('{0}\n'.format(output))
logfile.write('{0}\n\n'.format(traceback.format_exc()))
logfile.close()
return HttpResponse(output)
logfile.close()
return render_to_response("addNewClientInfo.html", data)
我希望clientInfo = ClientInfo.objects.get(tkz_api_id = tkz_ys_api_id, tkz_trans_key = tkz_ys_trans_key)中的input_new_client请求会抛出DoesNotExist个异常（因为我放入假数据以确保情况属实）。
所以，我只是在异常中调用add_new_client视图。
问题是input_new_client一直到new_client.save()行，由于显而易见的原因而失败。
有什么想法吗？
EDIT1：
我已将input_new_client视图修改为具有以下异常声明：
if (request.method == "POST"):
tkz_ys_api_id = request.POST.get("tkz_ys_api_id")
tkz_ys_trans_key = request.POST.get("tkz_ys_trans_key")
tkz_gateway_id = int(request.POST.get("tkz_gateway"))
## Validate the YS authentication information
try:
clientInfo = ClientInfo.objects.get(tkz_api_id = tkz_ys_api_id, tkz_trans_key = tkz_ys_trans_key)
except (ClientInfo.DoesNotExist, ClientInfo.MultipleObjectsReturned):
logfile.write('tkz_ys_api_id = {0}\n\n'.format(tkz_ys_api_id))
logfile.write('tkz_ys_trans_key = {0}\n\n'.format(tkz_ys_trans_key))
logfile.write('tkz_gateway_id = {0}\n\n'.format(tkz_gateway_id))
logfile.write('{0}\n\n'.format(traceback.format_exc()))
logfile.close()
state = "Invalid YS Authentication! Please try again."
add_new_client(request, state)
else:
if (clientInfo.name != "Your Solutions"):
state = "Invalid YS Authentication! Please try again."
add_new_client(request, state)
我知道它会进入异常 - 我可以使用日志信息和回溯进行验证。但是，它不会继续add_new_client。它反而向前跳过并尝试在ClientInfo模型中插入一个包含错误数据的新条目。
为什么要跳过对add_new_client的调用？
答案 0 :(得分：4)
这一行：
except ClientInfo.DoesNotExist or ClientInfo.MultipleObjectsReturned:
不符合您的想法。首先评估or，所以实际上（我认为）这只是试图捕获类型True的异常，当然这种异常从未引发过。你真正想要的是这个：
except (ClientInfo.DoesNotExist, ClientInfo.MultipleObjectsReturned):
（注意括号）。
另请注意，您的第二个代码段中的裸except子句是一个非常糟糕的主意：它会捕获所有异常，因此如果出现了您没想到的错误，那么永远都不会知道。确保只捕获except子句知道如何处理的处理错误。
修改
啊，我看到你现在正在做什么 - 你试图从异常内部向用户返回一个响应。嗯，这没有什么特别的，除了你实际上没有把它发回给用户：你只需要调用add_new_client()，并且不对发回的HTTP响应做任何事情。您需要从那里实际将其返回给用户：
except (ClientInfo.DoesNotExist, ClientInfo.MultipleObjectsReturned):
... logging stuff ...
state = "Invalid YS Authentication! Please try again."
return add_new_client(request, state)