How can I clear an image with Django Rest Framework?

Question

I thought my problem was https://github.com/encode/django-rest-framework/issues/937 which should have been fixed by https://github.com/encode/django-rest-framework/pull/1003 but it appears, whether I send in None or empty string, DRF isn't happy.

I'm using Django 1.11.6 and DRF 3.7.7

class Part(models.Model):
    image = models.ImageField(null=True, blank=True)

class PartSerializer(serializers.ModelSerializer):
    class Meta:
        model = Part
        fields = ('id', 'image')

class PartDetail(generics.RetrieveUpdateAPIView):
    queryset = Part.objects.all()
    serializer_class = PartSerializer
    parser_classes = (MultiPartParser, FormParser)

# put image, works fine
with tempfile.NamedTemporaryFile(suffix='.jpg') as fp:
    image = Image.new('RGB', (100, 200))
    image.save(fp)
    fp.seek(0)
    data = {'image': fp}
    self.client.put('/path/to/endpoint', data, format='multipart')

# clear image, attempt #1
data = {'image': None}
self.client.put('/path/to/endpoint', data, format='multipart')
AssertionError: {'image': ['The submitted data was not a file. Check the encoding type on the form.']}

# clear image, attempt #2
data = {'image': ''}
self.client.put('/path/to/endpoint', data, format='multipart')
AssertionError: <ImageFieldFile: None> is not None

Answer 1

You have to specify the image field explicitly to allow it to be null.

use this:

class PartSerializer(serializers.ModelSerializer):
    image = serializers.ImageField(max_length=None, allow_empty_file=True, allow_null=True, required=False)

    class Meta:
        model = Part
        fields = ('id', 'image')

check docs for more details.