def post(self, request, *args, **kwargs):
    form_class = self.get_form_class()
form = self.get_form(form_class)
if form.is_valid():
    return self.form_valid(form, **kwargs)
else:
    return self.form_invalid(form, **kwargs)

def form_valid(self, form, **kwargs):
    return HttpResponseRedirect(self.get_success_url())
Updating context data in FormView form_valid method?