serializers.py 文件源码

def perform_update(self, instance, validated_data, errors):
        """
        The main nested update logic implementation using nested fields and serializer
        """
        for field in self._writable_fields:
            if field.field_name not in validated_data:
                continue

            try:
                value = validated_data.get(field.field_name)

                if isinstance(field, BaseSerializer):

                    child_instance = getattr(instance, field.field_name, None)
                    child_instance = field.get_object(value, child_instance)

                    if child_instance and field.allow_nested_updates:
                        value = field.perform_update(child_instance, value, errors)
                    else:
                        value = child_instance

                elif isinstance(field, ListSerializer) and isinstance(field.child, BaseSerializer):

                    value = []

                    for item in validated_data.get(field.field_name):
                        child_instance = field.child.get_object(item)
                        if child_instance and (field.child.allow_create or field.child.allow_nested_updates):
                            v = field.child.perform_update(child_instance, item, errors)
                        else:
                            v = child_instance

                        if v:
                            value.append(v)

                self.update_attribute(instance, field, value)

            except Exception as e:
                errors.setdefault(field.field_name, []).append(' '.join(e.args))

        return instance