django HttpResponse in json

Question

I have a view :

def add_view(request):
    if request.method == "POST":

        files = request.FILES.getlist("file")
        response_data = {}

        for file in files:
            my_model = MyModel()
            my_model.my_file = file
            my_model.save()
            id_info = my_model.id
            response_data.append(id_info)

    return HttpResponse(json.dumps(response_data), content_type="application/json")

Here lets say if there are 5 files then I want to send the id of 5 file in response through json. Here its saying local variable response_data referenced before assignment.

I want to send the id of all 5 files. How to do this ?

Because you delcare `response_data` inside of the `for` loop — dursk, Mar 25 '15 at 19:09
Are you sure this is your exact code? This code would raise errors — karthikr, Mar 25 '15 at 19:15
Then you will need a key and value to store... like response_data['THE_KEY'] = id_info — tgpatel, Mar 25 '15 at 19:32
after doing that it says 'NoneType' object has no attribute 'has_header' — gamer, Mar 25 '15 at 19:35
can you verify that your Django version? Is it 1.7+ IF so change HttpResponse to JsonResponse http://stackoverflow.com/questions/2428092/creating-a-json-response-using-django-and-python/24411716#24411716 — tgpatel, Mar 25 '15 at 19:40

score 3 · Accepted Answer · answered Mar 25 '15 at 19:53

First you are defining response_data = {} inside the if and your return response is outside, because that you are getting response_data referenced before assignment error.

Second, a dict has not append() method. You should declare your responde_data as a list

def add_view(request):
    response_data = []
    if request.method == "POST":

        files = request.FILES.getlist("file")


        for file in files:
            my_model = MyModel()
            my_model.my_file = file
            my_model.save()
            id_info = my_model.id
            response_data.append(id_info)

    return HttpResponse(json.dumps(response_data), content_type="application/json")

what if I use dict. Using list will give me data in correct json format ? — gamer, Mar 25 '15 at 20:14
@gamer python list are json serializable, but is you want a dict, just wrapp it using {} `json.dumps({'response_data':response_data})` — levi, Mar 25 '15 at 20:32

django HttpResponse in json

1 Answers1