Use JSONResponse to serialize a QuerySet in Django

Question

I saw that now in Django 1.7 I can use the http.JSONResponse object to send JSON to a client. My View is:

#Ajax
def get_chat(request):
    usuario = request.GET.get('usuario_consultor', None)
    usuario_chat = request.GET.get('usuario_chat', None)

    mensajes = list(MensajeDirecto.objects.filter(Q(usuario_remitente = usuario, usuario_destinatario = usuario_chat) | Q(usuario_remitente = usuario_chat, usuario_destinatario = usuario)))


    return JsonResponse(mensajes, safe=False)

But I get the next error:

<MensajeDirecto: Towi CrisTowi> is not JSON serializable`

Do you know how to serialize a QuerySet to send it back in JSON form?

Answer 1

You shouldn't re-serialize with JsonResponse. You'll get a correctly formatted JSON response with:

from django.core import serializers
from django.http import HttpResponse

def my_view(request):
    my_model = MyModel.objects.all()
    response = serializers.serialize("json", my_model)
    return HttpResponse(response, content_type='application/json')

If you use a JsonResponse, it will coerce the already serialized JSON to a string, which is probably not what you want.

Note: Works with Django 1.10

Answer 2

from django.core import serializers
from django.http import JsonResponse

def get_chat(request):
    usuario = request.GET.get('usuario_consultor', None)
    usuario_chat = request.GET.get('usuario_chat', None)

    mensajes = MensajeDirecto.objects.filter(Q(usuario_remitente = usuario, usuario_destinatario = usuario_chat) | Q(usuario_remitente = usuario_chat, usuario_destinatario = usuario))

    return JsonResponse(serializers.serialize('json', mensajes), safe=False)

Ref: https://docs.djangoproject.com/en/dev/ref/request-response/#jsonresponse-objects https://docs.djangoproject.com/en/1.7/topics/serialization/