nested_update.py 文件源码

def update(self, instance, validated_data):
        reverse_relations = OrderedDict()
        relations = OrderedDict()

        # Sort fields by create priority
        fields = self.get_sorted_by_create_priority(self.fields)
        # Remove related fields from validated data for future manipulations
        for field_name, field in fields.items():
            if field.read_only:
                continue

            if isinstance(field, serializers.ListSerializer):
                if isinstance(field.child, serializers.ModelSerializer):
                    if validated_data.pop(field.source, None) is None:
                        # Skip field if field is not required or null allowed
                        continue
                    reverse_relations[field_name] = field.child

            if isinstance(field, serializers.ModelSerializer):
                if validated_data.pop(field.source, None) is None:
                    # Skip field if field is not required or null allowed
                    continue
                relations[field_name] = field

        nested_related_kwarg = getattr(self.Meta, 'nested_related_kwarg', None)
        if reverse_relations:
            assert nested_related_kwarg, \
                "Set `nested_related_kwarg` in Meta options for use nested " \
                "create feature"

        if relations:
            raise NotImplementedError("NestedUpdateMixin not provide update "
                                      "for direct relations")

        # Update instance
        instance = super(NestedUpdateMixin, self).update(
            instance, validated_data)

        if reverse_relations:
            self.update_reverse_relations(instance, reverse_relations)
            self.delete_reverse_relations_if_need(instance, reverse_relations)
        return instance