Django-“NoneType”对象不是callab

Question

我在重定向到结果页时出现此错误。这是因为在重定向页面中，“POST.get”函数在重定向之前无法获取用户在表单中输入的内容吗？

视图.py

class InputFormView(FormView):
    template_name = 'inputform.html'
    form_class = InputForm

    def get_success_url(self):
        return ''.join(
        [
            reverse('result'),
            '?company=',self.request.POST.get('company'),
            '&region=',self.request.POST.get('region')  <is there anything wrong here---？       
        ]
        )


class ReulstView(FormView):
    context_object_name = 'result_list'
    template_name = 'result_list.html'
    model = Result

    if form.is_valid():
        company = form.cleaned_data['company']
        region = form.cleaned_data['region']

        self.queryset=Result.objects.filter(region=region)

        return render(request, 'result_list.html', {'form': form})

    def get_context_data(self, **kwargs):
        context = super(ReulstView, self).get_context_data(**kwargs)
        context["sales"] = self.get_queryset().aggregate(Sum('sales'))

        context["company"] = self.request.POST.get("company")
        context["region"] = self.request.POST.get("region")

        return context

    def get_queryset(self):
        return Result.objects.all()

回溯：

File "C:\Python27\lib\site-packages\django-1.8.3-py2.7.egg\django\core\handlers\base.py" in get_response
  132.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "C:\Python27\lib\site-packages\django-1.8.3-py2.7.egg\django\views\generic\base.py" in view
  71.             return self.dispatch(request, *args, **kwargs)
File "C:\Python27\lib\site-packages\django-1.8.3-py2.7.egg\django\views\generic\base.py" in dispatch
  89.         return handler(request, *args, **kwargs)
File "C:\Python27\lib\site-packages\django-1.8.3-py2.7.egg\django\views\generic\edit.py" in get
  205.         form = self.get_form()
File "C:\Python27\lib\site-packages\django-1.8.3-py2.7.egg\django\views\generic\edit.py" in get_form
  74.         return form_class(**self.get_form_kwargs())

Exception Type: TypeError at /result_list/
Exception Value: 'NoneType' object is not callable

输入

class InputForm(forms.ModelForm):
    company=forms.CharField(widget=forms.TextInput, label="Company",error_messages={'required': 'Please enter the company name'},required=True)

    #region   This form can display correctly with drop down list
    iquery = Dupont.objects.values_list('region', flat=True).distinct()
    iquery_choices = [('', 'None')] + [(region,region)  for region in iquery]
    region = forms.ChoiceField(choices=iquery_choices)

对于同一个函数，我尝试了另一个代码，尽管没有错误，但是不能显示表单数据，它显示为none。希望您能在以下链接中回答我的问题：

django- why after redirecting, the form display "None"

Answer 1

我认为这是您的问题：您使用的是FormView，但尚未定义要使用的表单类。在类上设置一个form_class属性，或者重写get_form_class方法：

class ReulstView(FormView):
    context_object_name = 'result_list'
    template_name = 'result_list.html'
    model = Result
    form_class = InputForm

另外，form_valid方法将接收表单实例，您不需要手动实例化它：

def form_valid(self, form, **kwargs):
    form = InputForm(self.request.POST)  # <- remove this line
    if form.is_valid():
    ...

Answer 2

让我们再做一条线。:) 唯一可以得到“return outside function”错误的方法是尝试从函数返回某些内容。：）通常可能是因为类型错误或缩进错误。 请提供出现此错误的代码，好吗？我相信那里的凹痕有问题。

class ReulstView(FormView):
    context_object_name = 'result_list'
    template_name = 'result_list.html'
    model = Result

    if form.is_valid(): # <- it is not a function or method
                        #  it is a class declaration  
        company = form.cleaned_data['company']
        region = form.cleaned_data['region']

        self.queryset=Result.objects.filter(region=region)

        return render(request, 'result_list.html', {'form': form})
     def get_context_data(self, **kwargs): #<- and this is a method
        #... all your following code

我不熟悉Django FormViews，但看起来正确的代码可能是这样的：

class ResultView(FormView):
    context_object_name = 'result_list'
    template_name = 'result_list.html'
    model = Result

    def form_valid(self, form):
        company = form.cleaned_data['company']
        region = form.cleaned_data['region']
        self.queryset=Result.objects.filter(region=region)    
        return render(request, 'result_list.html', {'form': form})