How to set HTTP header for JSON message from django-piston handler?

Question

In the piston handler, I need to return django.db.models.query.QuerySet as the correct JSON message (reflecting the model and request), and also add the HttpResponse header. So far, I can do one or the other, but not both (and get an adequate JSON response).

The following generates the correct formatted JSON response, but without adding the HttpResponse header (not shown):

class PollHandlerSearch(BaseHandler):
    allowed_methods = ('POST')
    model = Poll
    fields = ('id', 'question', 'pub_date')
    KEYS =  ( 'question', 'start-date', 'end-date' )

    def create(self, request):
        post = Poll.objects.all()
        for skey in self.KEYS:
            if len(post) and request.POST.has_key(skey) and len(request.POST[skey]):
                if skey == self.KEYS[0]:
                        post = post.filter(question__icontains=request.POST[skey])
                elif skey == self.KEYS[1]:
                        post = post.filter(pub_date__gte=request.POST[skey])
                elif skey == self.KEYS[2]:
                        post = post.filter(pub_date__lte=request.POST[skey])
        return post

The resulting correctly formatted JSON message:

[
    {
        "pub_date": "2010-08-23 22:15:07", 
        "question": "What up?", 
        "id": 1
    }
]

Below is an HttpResponse with an added header and a JSONish response is generated, but one that is not expected or does not want, plus does not reflect any django 'DateTimeAwareJSONEncoder' (used by piston JSONEmitter).

class PollHandlerSearch(BaseHandler):
    allowed_methods = ('POST')
    model = Poll
    fields = ('id', 'question', 'pub_date')
    KEYS =  ( 'question', 'start-date', 'end-date' )

    def create(self, request):
        resp = HttpResponse()
        post = Poll.objects.all()
        for skey in self.KEYS:
            if len(post) and request.POST.has_key(skey) and len(request.POST[skey]):
                if skey == self.KEYS[0]:
                        post = post.filter(question__icontains=request.POST[skey])
                elif skey == self.KEYS[1]:
                        post = post.filter(pub_date__gte=request.POST[skey])
                elif skey == self.KEYS[2]:
                        post = post.filter(pub_date__lte=request.POST[skey])
        json_serializer = serializers.get_serializer("json")()
        json_serializer.serialize(post, ensure_ascii=False, indent=4, stream=resp)
        resp['MYHEADER'] = 'abc123'
        return resp

JSONish:

[
    {
        "pk": 1, 
        "model": "polls.poll", 
        "fields": {
            "pub_date": "2010-08-23 22:15:07", 
            "question": "What up?"
        }
    }
]

, , , JSON, JSONEmitter , , , , "".

emitters.py ( OOP/Python/django/piston). JSON HTTP, , ?

Answer 1

piston.resource.Resource , __call__.   

class MyResource(Resource):
    def __call__(self, request, *args, **kwargs):
        resp = super(MyResource, self).__call__(request, *args, **kwargs)
        resp['HEADER'] = "abc123"
        return resp

urls.py:

def BasicResource(handler):
    return resource.MyResource(handler=handler, authentication=basic)

your_handler = BasicResource(YourHandlerClass)
another_handler = BasicResource(AnotherHandlerClass)