object_lookup_mixin.py 文件源码

def pre_save(self, obj):
        """
        Set any attributes on the object that are implicit in the request.
        """
        # pk and/or slug attributes are implicit in the URL.
        lookup = self.kwargs.get(self.lookup_field, None)
        pk = self.kwargs.get(self.pk_url_kwarg, None)
        slug = self.kwargs.get(self.slug_url_kwarg, None)
        slug_field = slug and self.slug_field or None

        if lookup:
            serializer = self.get_serializer()
            k = serializer.get_fields()[self.lookup_field]
            queryset = self.get_queryset()
            queryset = self.filter_queryset(queryset)
            if isinstance(k, serializers.HyperlinkedRelatedField):
                filter = {}
                lookup_field = '%s__%s' % (self.lookup_field, k.lookup_field)
                filter[lookup_field] = lookup
                k_obj = get_object_or_404(queryset, **filter)
                lookup = getattr(k_obj, self.lookup_field)
            setattr(obj, self.lookup_field, lookup)

        if pk:
            setattr(obj, 'pk', pk)

        if slug:
            setattr(obj, slug_field, slug)

        # Ensure we clean the attributes so that we don't eg return integer
        # pk using a string representation, as provided by the url conf kwarg.
        if hasattr(obj, 'full_clean'):
            exclude = mixins._get_validation_exclusions(
                obj, pk, slug_field, self.lookup_field)
            obj.full_clean(exclude)