Request.data empty when multipart/form-data POSTed · Issue #3951 · encode/django-rest-framework (original) (raw)

Django==1.9.2
djangorestframework==3.3.2

This is essentially a repost of #3814. There is already some research and discussion attached to that issue that I will not rehash, but the author closed out the item once a workaround was found.

Is that workaround the long term solution? Is the answer to never touch the Django Request before DRF has a chance to do its thing? This can be difficult to control in projects with third party middleware.

The issue seems to be that, when POSTing data, Django is exhausting the underlying request stream if the WSGIRequest is accessed prior to initialize_request in the DRF View dispatcher. PUTs seem to be unaffected.

A totally contrived example that demonstrates the issue. First example, presuming no middleware Request meddling...

class TestView(APIView):

def post(self, request, *args, **kwargs):
    # request.data, .FILES, and .POST are populated
    # request._request.FILES and .POST are empty
    return Response()

def put(self, request, *args, **kwargs):
    # request.data, .FILES, and .POST are populated
    # request._request.FILES and .POST are empty
    return Response()

Second example, forcibly evaluating the Django request before dispatching.

class TestView(APIView):

def dispatch(self, request, *args, **kwargs):
    p = request.POST  # Force evaluation of the Django request
    return super().dispatch(request, *args, **kwargs)

def post(self, request, *args, **kwargs):
    # request.data, .FILES, and .POST are empty
    # request._request.FILES and .POST are populated
    return Response()

def put(self, request, *args, **kwargs):
    # request.data, .FILES, and .POST are populated
    # request._request.FILES and .POST are empty
    return Response()

Cheers!