Django Rest Framework: Nested Serializers with FileField/ImageField

Question

I have a serializer that follows a model similar to:

class Ticket:
    customer = Customer()
    ...
class Customer:
    signature = FileField()
    name = CharField()

And I would like to use DRF's serializers to POST a new 'Ticket', so I send multipart/form data with the signature file AND the necessary 'application/json' data.

The resulting request, after collecting the FILES and DATA, looks like this:

>>> request.FILES
<MultiValueDict: {u'customer.signature': [<InMemoryUploadedFile: signature.jpg (image/jpeg)>]}>
>>> data
{u'customer': {u'name': u'Test'}, ... }
>>> serializer = TicketSerializer(data=data, files=request.FILES)
>>> serializer.is_valid()
False
>>> serializer.errors
{'customer': [{'signature': [u'This field is required.']}]}

How do I use the DRF Serializers/Fields to fill ImageFields/FileFields inside the 'customer' layer?

Answer 1

Since it appears I'm not the only one who has this problem, this was the solution I came up with:

The most straight-forward answer is to take the uploaded ImageField/FileField and apply them into the appropriate position with the nested 'data' portion of the serializer. In my case, this would be inside the 'customer' dict.

Once the files have been properly applied to data, we can drop the 'files=' variable, since all the files are now included in data.

A working example in code would look something like this:

>>> request.FILES
<MultiValueDict: {u'customer.signature': [<InMemoryUploadedFile: signature.jpg (image/jpeg)>]}>
>>> data
{u'customer': {u'name': u'Test'}, ... }
if 'customer.signature' in request.FILES:
    data['customer']['signature_file'] = request.FILES['customer.signature']
>>> serializer = TicketSerializer(data=data)
>>> serializer.is_valid()
True