diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py index be8ad3f24..b3db35823 100644 --- a/rest_framework/serializers.py +++ b/rest_framework/serializers.py @@ -625,6 +625,20 @@ class ModelSerializerOptions(SerializerOptions): self.write_only_fields = getattr(meta, 'write_only_fields', ()) +def _get_class_mapping(mapping, obj): + """ + Takes a dictionary with classes as keys, and an object. + Traverses the object's inheritance hierarchy in method + resolution order, and returns the first matching value + from the dictionary or None. + + """ + return next( + (mapping[cls] for cls in inspect.getmro(obj.__class__) if cls in mapping), + None + ) + + class ModelSerializer(Serializer): """ A serializer that deals with model instances and querysets. @@ -899,15 +913,17 @@ class ModelSerializer(Serializer): models.URLField: ['max_length'], } - if model_field.__class__ in attribute_dict: - attributes = attribute_dict[model_field.__class__] + attributes = _get_class_mapping(attribute_dict, model_field) + if attributes: for attribute in attributes: kwargs.update({attribute: getattr(model_field, attribute)}) - try: - return self.field_mapping[model_field.__class__](**kwargs) - except KeyError: - return ModelField(model_field=model_field, **kwargs) + serializer_field_class = _get_class_mapping( + self.field_mapping, model_field) + + if serializer_field_class: + return serializer_field_class(**kwargs) + return ModelField(model_field=model_field, **kwargs) def get_validation_exclusions(self, instance=None): """