django- why after redirecting, the form display “None”

Question

I have a form, after entering the information, based on infomation it filters the database and do some calculation and finally displays the result to a redirected url.

Answer 1

Your code should work if you change your get_queryset method to:

def get_queryset(self):
    # You are sending GET params here, not POST
    form = InputForm(self.request.GET)
    if form.is_valid():
        company = form.cleaned_data['company']
        region = form.cleaned_data['region']

        queryset=Result.objects.filter(region=region)
        return queryset
    return Result.objects.all()

and your get_context_data method to:

def get_context_data(self, **kwargs):
    context = super(ResultView, self).get_context_data(**kwargs)
    context["sales"] = self.get_queryset().aggregate(Sum('sales'))
    # Your variables are in GET, not POST
    context["company"] = self.request.GET.get("company")
    context["region"] = self.request.GET.get("region")
    return context

That said, your code could do with some refactoring. Do you really need the FormView that accepts a POST request? You could instead have a form that submits directly via GET to your result view.

With your current approach you are actually processing the form twice - once in each of your views.

Edit: also, they way you are generating your redirect url isn't safe. You should so something like this instead:

import urllib
def get_success_url(self):
    params = {
        'company': self.request.POST.get('company'),
        'region': self.request.POST.get('region')
    }

    return ''.join([reverse('result'), '?', urllib.urlencode(params.items())])