django-'NoneType' 对象不可调用

Question

I got this error, when redirecting to the result page. Is that because in the redirected page, the "POST.get" function cannot get what the user has entered in the form before redirecting?

views.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()

Traceback:

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

Inputform

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)

For the same function, I tried another code, even though without error but cannot display the form data, it displays as none. Hope you can answer my question in the following link:

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

Answer 1

I think this is your issue: You are using a FormView but haven't defined a form class to use. Either set a form_class attr on the class, or override the get_form_class method:

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

Also, the form_valid method will receive the form instance, you don't need to instantiate it manually:

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

Answer 2

Lets make another thread. :) The only way you can get "return outside function" error - you are trying to return something not from function. :) It could happen usually because of misstype or wrong indentation. Could you please provide the code where you get this error? I believe that there is something wrong with indentation there.

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

I'm not familiar with Django FormViews, but looks like correct code could be like this:

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})

Answer 3

Chances are that the problem is with your forms.py file. When you are importing and using the model in your forms.py file you are using parenthesis to define your model which you should not. For example if your model is lets suppose Post, It should be defined as Post instead of Post()