How to use MultiPartParser in Django Rest Framework

Question

I need to upload a file and some JSON associated with it. But I don't understand how to save the different parts, specifically the JSON part i.e. I'm able to save the image but not the JSON.

I read that I need to use a MultiPartParser but I can't figure out how to integrate it correctly into my serializer class.

Here is the multi-part request that my Server is receiving:

<QueryDict: {'geo': ['{"point" : { "type:" : "Point", "coordinates" : [11.51350462236356, -22.70903491973877]}}'], 'picture': [<TemporaryUploadedFile: photo3.jpg (image/*)>]}>

Here is the view:

class UserUploadedPicture(APIView):

    def post(self, request, format=None):
        print(request.data)
        print("\n\n\n")
        serializer = PictureSerializer(data=request.data)
        if serializer.is_valid():
            serializer.save()
            return JsonResponse(serializer.data)
        return JsonResponse(serializer.errors, status=400)

Here is the serializer:

class PictureSerializer(GeoFeatureModelSerializer):
    class Meta:
        model = Pictures
        geo_field = "point"
        fields = ('picture', 'processed', 'flagged', 'point')

Here is the model:

class Pictures(models.Model):
    objects = models.GeoManager()
    picture = models.ImageField(null=True, default=None, blank=True)
    processed = models.BooleanField(default=False)
    flagged = models.BooleanField(default=False)
    point = models.PointField(null=True, default=None, blank=True)

Can anyone please tell me how to serialize the point field correctly? Maybe I need to change the JSON format? Maybe I need to change the serializer?

Answer 1

As to integrating the MultiPartParser, it is done with the View, since it is responsible of receiving the request and handling it, not the Serializer. You are using a class-based view and defining the parser is done using the parser_classes attribute as explained in the same link to the official documentation you provided.

So your View becomes:

class UserUploadedPicture(APIView):
    parser_classes = (MultiPartParser, )

    def post(self, request, format=None):
        print(request.data)
        print("\n\n\n")
        serializer = PictureSerializer(data=request.data)
        if serializer.is_valid():
            serializer.save()
            return JsonResponse(serializer.data)
        return JsonResponse(serializer.errors, status=400)

And concerning your Serializer for the PointField, check this SO answer