FormView override render_to_response (JSON-response)

[m.vovcu@…]

Hi,

I'm rewriting an application of mine to user CBV instead of functions. I stuck at a point where I wanted to return a JSON response inside the form_invalid function but always got a view didn't return an HttpResponse object-error. Therefore I thought to myself to try it inside the post function where it suddenly worked.

To spare us words, here's my setup (simplified for better readability):

urls.py:

url( r'^{plans/$', login_required( MainView.as_view(}

context_object_name='services',
model = Service,
template_name = 'plans.html',
paginate_by = 5,
form_class = addServiceForm,
success_url = reverse_lazy('plans')) ),

name="plans" ),

views.py:

class MainView(ListView, FormMixin):

# NOTICE: I put this only here for completion
def get(self, request, *args, kwargs):

view = DefView.as_view( context_object_name=self.context_object_name, model=self.model, queryset=self.queryset, template_name=self.template_name, paginate_by=self.paginate_by, form_class=self.form_class, success_url=self.success_url )
return view(request, *args, kwargs)

# NOTICE: here's our patient
def post(self, request, *args, kwargs):

view = SubTestView.as_view( template_name=self.template_name, form_class=self.form_class, success_url=self.success_url )

#This one does NOT work
class SubTestView(FormView):

def render_to_json_response(self, context, response_kwargs):

data = json.dumps(context)
response_kwargscontent_type = 'application/json'
return HttpResponse(data, response_kwargs)

def post(self, request, *args, kwargs):

form_class = self.get_form_class()
form = self.get_form(form_class)
self.form_invalid(form)

def form_invalid(self, form):

data = {

'pk': "Test_PK",

}

return self.render_to_json_response(data)

#This one DOES work
class SubTestView(FormView):

def render_to_json_response(self, context, response_kwargs):

data = json.dumps(context)
response_kwargscontent_type = 'application/json'
return HttpResponse(data, response_kwargs)

def post(self, request, *args, kwargs):

form_class = self.get_form_class()
form = self.get_form(form_class)
data = {

'pk': "Test_PK",

}

return self.render_to_json_response(data)

Well, regarding the code I don't really see any difference. Am I doing something wrong or is this just a bug?

Tested with following setups:
OSX 10.9.2, Python 2.7/3.3/3.4, Django 1.6.2/1.5

Regards
marius

[Claude Paroz]

I'm a bit skeptical that there is a bug in form_invalid. Try to make and attach to this ticket a sample project which demonstrates this issue.