double save

[Lewiscowles1986]

Not sure if this can be integrated, but it would be nice to see it as it's one of the most common things I encounter across a range of technologies (not just python or django)

So I recently saw this in some django code (I've made it generic)

class ItemViewSet(viewsets.ModelViewSet):
    queryset = models.Item.objects.all()
    serializer_class = ItemSerializer

    def perform_create(self, serializer):
        instance = serializer.save()
        instance.url = reverse('item-detail', args=[instance.pk], request=self.request)
        instance.save()

This causes a double-save to a single instance, which IMO is never acceptable and a sign of a bad design.

Instead I recommend adding this to ItemSerializer (basically generating every time before sending to view)

class ItemSerializer(HyperlinkedModelSerializer):
    url = HyperlinkedIdentityField(view_name='item-detail', read_only=True)