diff --git a/rest_framework/relations.py b/rest_framework/relations.py index aa0c2defe..13793f375 100644 --- a/rest_framework/relations.py +++ b/rest_framework/relations.py @@ -338,7 +338,12 @@ class ManyRelatedField(Field): # We override the default field access in order to support # lists in HTML forms. if html.is_html_input(dictionary): + # Don't return [] if the update is partial + if self.field_name not in dictionary: + if getattr(self.root, 'partial', False): + return empty return dictionary.getlist(self.field_name) + return dictionary.get(self.field_name, empty) def to_internal_value(self, data): diff --git a/tests/test_relations.py b/tests/test_relations.py index 62353dc25..d478d8550 100644 --- a/tests/test_relations.py +++ b/tests/test_relations.py @@ -1,6 +1,8 @@ from .utils import mock_reverse, fail_reverse, BadType, MockObject, MockQueryset from django.core.exceptions import ImproperlyConfigured +from django.utils.datastructures import MultiValueDict from rest_framework import serializers +from rest_framework.fields import empty from rest_framework.test import APISimpleTestCase import pytest @@ -134,3 +136,34 @@ class TestSlugRelatedField(APISimpleTestCase): def test_representation(self): representation = self.field.to_representation(self.instance) assert representation == self.instance.name + + +class TestManyRelatedField(APISimpleTestCase): + def setUp(self): + self.instance = MockObject(pk=1, name='foo') + self.field = serializers.StringRelatedField(many=True) + self.field.field_name = 'foo' + + def test_get_value_regular_dictionary_full(self): + assert 'bar' == self.field.get_value({'foo': 'bar'}) + assert empty == self.field.get_value({'baz': 'bar'}) + + def test_get_value_regular_dictionary_partial(self): + setattr(self.field.root, 'partial', True) + assert 'bar' == self.field.get_value({'foo': 'bar'}) + assert empty == self.field.get_value({'baz': 'bar'}) + + def test_get_value_multi_dictionary_full(self): + mvd = MultiValueDict({'foo': ['bar1', 'bar2']}) + assert ['bar1', 'bar2'] == self.field.get_value(mvd) + + mvd = MultiValueDict({'baz': ['bar1', 'bar2']}) + assert [] == self.field.get_value(mvd) + + def test_get_value_multi_dictionary_partial(self): + setattr(self.field.root, 'partial', True) + mvd = MultiValueDict({'foo': ['bar1', 'bar2']}) + assert ['bar1', 'bar2'] == self.field.get_value(mvd) + + mvd = MultiValueDict({'baz': ['bar1', 'bar2']}) + assert empty == self.field.get_value(mvd)