Django-视图未返回HttpResponse对象

Question

I'm facing this exception error and I'm puzzled by it, as this method worked in similar system, appreciate any help or pointers. Many Thanks!

Exception Value: The view Project.qna.views.add_vote didn't return an HttpResponse object.

def add_vote(request):

if request.method == "POST":
    q_id = request.POST['vote_form_q_id']
    a_id = request.POST['vote_form_a_id']
    vote_value = request.POST['vote_form_value']

    ok = False
    vote_num = None
    name = None

    if q_id:
        try:
            question = Question.objects.get(id=q_id)
            question.num_vote += int(vote_value)
            question.save()
            vote_num = question.num_vote
            name = 'Question_'+str(q_id)
            ok = True

        except Question.DoesNotExist:
            pass
    elif a_id:
        try:
            answer = Answer.objects.get(id=a_id)
            answer.num_vote += int(vote_value)
            answer.save()
            vote_num = answer.num_vote
            name = 'Answer_'+str(a_id)
            ok = True
        except Answer.DoesNotExist:
            pass

    if ok and request.is_ajax:
        result = simplejson.dumps({
            "vote_num": vote_num,
        }, cls=LazyEncoder)
        response = HttpResponse(result, mimetype='application/javascript')

        response.set_cookie(name, datetime.now)
    return response

Answer 1

Fix your indention please, also you seem to have a lot of workarounds that could be simplified.

Every django view should return a HttpResponse object, you seem to have a lot of places where this would not be the case. To narrow down your problem change every pass to a print statement to see where your code actually fails. It would be quite helpful if you could present your POST data.

Answer 2

Well it's hard to tell without seeing what kind of request you are making to the view. But are you sending a POST request? Because you don't handle GET requests in any way. Also the indentation is wrong. But that might just be cutting and pasting gone awry.

Answer 3

This is untested, but it's a cleaner and more robust design, which I believe fits in with your logic and highlights the points where returning an HttpResponse is necessary:

def add_vote(request):
    if not (request.method == 'POST' and request.is_ajax):
        return # Some suitable response here
    try:
        vote_value = int(request.POST.get('vote_form_value',''))
    except ValueError as e:
        pass # Some suitable response here

    def saveobj(model, key, val): # helper function to reduce code repetition
        item = model.objects.get(id=key)
        item.num_vote += val
        item.save()
        return item.num_vote, '%s_%s' % (model.__class__.__name__, key)

    for model, key in [(Question, 'vote_form_q_id'), (Answer, 'vote_form_a_id')]):
        try:
            new_vote_value, name = saveobj(model, request.POST[key], vote_value)
            break
        except (KeyError, ObjectDoesNotExist) as e:
            continue # or error out
    else:
        pass # neither question or answer found - so suitable response here

    # return ajax response here....