http://chriskief.com/2013/05/17/django-mixins-requiresigninajax-and-jsonresponsemixin/

requiresigninajax.py

from django.utils.decorators import method_decorator
from app.lib.ajax import login_required_ajax


class RequireSignInAjax(object):

    @method_decorator(login_required_ajax())
    def dispatch(self, request, *args, **kwargs):
        return super(RequireSignInAjax, self).dispatch(request, *args, **kwargs)