Merge pull request #556 from maspwr/one-to-one-nested

One-to-one writable, nested serializer support

2 files changed, 177 insertions, 8 deletions

diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index 27458f96..a84370e9 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -93,7 +93,7 @@ class SerializerOptions(object):
         self.exclude = getattr(meta, 'exclude', ())
 
 
-class BaseSerializer(Field):
+class BaseSerializer(WritableField):
     class Meta(object):
         pass
 
@@ -118,6 +118,7 @@ class BaseSerializer(Field):
         self._data = None
         self._files = None
         self._errors = None
+        self._delete = False
 
     #####
     # Methods to determine which fields to use when (de)serializing objects.
@@ -218,7 +219,10 @@ class BaseSerializer(Field):
             try:
                 field.field_from_native(data, files, field_name, reverted_data)
             except ValidationError as err:
-                self._errors[field_name] = list(err.messages)
+                if hasattr(err, 'message_dict'):
+                    self._errors[field_name] = [err.message_dict]
+                else:
+                    self._errors[field_name] = list(err.messages)
 
         return reverted_data
 
@@ -369,6 +373,35 @@ class ModelSerializer(Serializer):
     """
     _options_class = ModelSerializerOptions
 
+    def field_from_native(self, data, files, field_name, into):
+        if self.read_only:
+            return
+
+        try:
+            value = data[field_name]
+        except KeyError:
+            if self.required:
+                raise ValidationError(self.error_messages['required'])
+            return
+
+        if self.parent.object:
+            # Set the serializer object if it exists
+            pk_field_name = self.opts.model._meta.pk.name
+            obj = getattr(self.parent.object, field_name)
+            self.object = obj
+
+        if value in (None, ''):
+            self._delete = True
+            into[(self.source or field_name)] = self
+        else:
+            obj = self.from_native(value, files)
+            if not self._errors:
+                self.object = obj
+                into[self.source or field_name] = self
+            else:
+                # Propagate errors up to our parent
+                raise ValidationError(self._errors)
+
     def get_default_fields(self):
         """
         Return all the fields that should be serialized for the model.
@@ -542,10 +575,13 @@ class ModelSerializer(Serializer):
 
         return instance
 
-    def save(self):
-        """
-        Save the deserialized object and return it.
-        """
+    def _save(self, parent=None, fk_field=None):
+        if self._delete:
+            self.object.delete()
+            return
+
+        if parent and fk_field:
+            setattr(self.object, fk_field, parent)
         self.object.save()
 
         if getattr(self, 'm2m_data', None):
@@ -555,9 +591,18 @@ class ModelSerializer(Serializer):
 
         if getattr(self, 'related_data', None):
             for accessor_name, object_list in self.related_data.items():
-                setattr(self.object, accessor_name, object_list)
+                if isinstance(object_list, ModelSerializer):
+                    fk_field = self.object._meta.get_field_by_name(accessor_name)[0].field.name
+                    object_list._save(parent=self.object, fk_field=fk_field)
+                else:
+                    setattr(self.object, accessor_name, object_list)
             self.related_data = {}
-
+            
+    def save(self):
+        """
+        Save the deserialized object and return it.
+        """
+        self._save()
         return self.object
 
 
diff --git a/rest_framework/tests/nesting.py b/rest_framework/tests/nesting.py
new file mode 100644
index 00000000..e4e32667
--- /dev/null
+++ b/rest_framework/tests/nesting.py
@@ -0,0 +1,124 @@
+from django.db import models
+from django.test import TestCase
+from rest_framework import serializers
+
+
+class OneToOneTarget(models.Model):
+    name = models.CharField(max_length=100)
+
+
+class OneToOneTargetSource(models.Model):
+    name = models.CharField(max_length=100)
+    target = models.OneToOneField(OneToOneTarget, null=True, blank=True,
+                                  related_name='target_source')
+
+
+class OneToOneSource(models.Model):
+    name = models.CharField(max_length=100)
+    target_source = models.OneToOneField(OneToOneTargetSource, related_name='source')
+
+
+class OneToOneSourceSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = OneToOneSource
+        exclude = ('target_source', )
+
+
+class OneToOneTargetSourceSerializer(serializers.ModelSerializer):
+    source = OneToOneSourceSerializer()
+
+    class Meta:
+        model = OneToOneTargetSource
+        exclude = ('target', )
+
+class OneToOneTargetSerializer(serializers.ModelSerializer):
+    target_source = OneToOneTargetSourceSerializer()
+
+    class Meta:
+        model = OneToOneTarget
+
+
+class NestedOneToOneTests(TestCase):
+    def setUp(self):
+        for idx in range(1, 4):
+            target = OneToOneTarget(name='target-%d' % idx)
+            target.save()
+            target_source = OneToOneTargetSource(name='target-source-%d' % idx, target=target)
+            target_source.save()
+            source = OneToOneSource(name='source-%d' % idx, target_source=target_source)
+            source.save()
+
+    def test_one_to_one_retrieve(self):
+        queryset = OneToOneTarget.objects.all()
+        serializer = OneToOneTargetSerializer(queryset)
+        expected = [
+            {'id': 1, 'name': u'target-1', 'target_source': {'id': 1, 'name': u'target-source-1', 'source': {'id': 1, 'name': u'source-1'}}},
+            {'id': 2, 'name': u'target-2', 'target_source': {'id': 2, 'name': u'target-source-2', 'source': {'id': 2, 'name': u'source-2'}}},
+            {'id': 3, 'name': u'target-3', 'target_source': {'id': 3, 'name': u'target-source-3', 'source': {'id': 3, 'name': u'source-3'}}}            
+        ]
+        self.assertEquals(serializer.data, expected)
+        
+
+    def test_one_to_one_create(self):
+        data = {'id': 4, 'name': u'target-4', 'target_source': {'id': 4, 'name': u'target-source-4', 'source': {'id': 4, 'name': u'source-4'}}}
+        serializer = OneToOneTargetSerializer(data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEquals(serializer.data, data)
+        self.assertEqual(obj.name, u'target-4')
+
+        # Ensure (target 4, target_source 4, source 4) are added, and
+        # everything else is as expected.
+        queryset = OneToOneTarget.objects.all()
+        serializer = OneToOneTargetSerializer(queryset)
+        expected = [
+            {'id': 1, 'name': u'target-1', 'target_source': {'id': 1, 'name': u'target-source-1', 'source': {'id': 1, 'name': u'source-1'}}},
+            {'id': 2, 'name': u'target-2', 'target_source': {'id': 2, 'name': u'target-source-2', 'source': {'id': 2, 'name': u'source-2'}}},
+            {'id': 3, 'name': u'target-3', 'target_source': {'id': 3, 'name': u'target-source-3', 'source': {'id': 3, 'name': u'source-3'}}},
+            {'id': 4, 'name': u'target-4', 'target_source': {'id': 4, 'name': u'target-source-4', 'source': {'id': 4, 'name': u'source-4'}}}
+        ]
+        self.assertEquals(serializer.data, expected)
+
+    def test_one_to_one_create_with_invalid_data(self):
+        data = {'id': 4, 'name': u'target-4', 'target_source': {'id': 4, 'name': u'target-source-4', 'source': {'id': 4}}}
+        serializer = OneToOneTargetSerializer(data=data)
+        self.assertFalse(serializer.is_valid())
+        self.assertEquals(serializer.errors, {'target_source': [{'source': [{'name': [u'This field is required.']}]}]})
+
+    def test_one_to_one_update(self):
+        data = {'id': 3, 'name': u'target-3-updated', 'target_source': {'id': 3, 'name': u'target-source-3-updated', 'source': {'id': 3, 'name': u'source-3-updated'}}}
+        instance = OneToOneTarget.objects.get(pk=3)
+        serializer = OneToOneTargetSerializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEquals(serializer.data, data)
+        self.assertEqual(obj.name, u'target-3-updated')
+
+        # Ensure (target 3, target_source 3, source 3) are updated,
+        # and everything else is as expected.
+        queryset = OneToOneTarget.objects.all()
+        serializer = OneToOneTargetSerializer(queryset)
+        expected = [
+            {'id': 1, 'name': u'target-1', 'target_source': {'id': 1, 'name': u'target-source-1', 'source': {'id': 1, 'name': u'source-1'}}},
+            {'id': 2, 'name': u'target-2', 'target_source': {'id': 2, 'name': u'target-source-2', 'source': {'id': 2, 'name': u'source-2'}}},
+            {'id': 3, 'name': u'target-3-updated', 'target_source': {'id': 3, 'name': u'target-source-3-updated', 'source': {'id': 3, 'name': u'source-3-updated'}}}
+        ]
+        self.assertEquals(serializer.data, expected)
+
+    def test_one_to_one_delete(self):
+        data = {'id': 3, 'name': u'target-3', 'target_source': None}
+        instance = OneToOneTarget.objects.get(pk=3)
+        serializer = OneToOneTargetSerializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+
+        # Ensure (target_source 3, source 3) are deleted,
+        # and everything else is as expected.
+        queryset = OneToOneTarget.objects.all()
+        serializer = OneToOneTargetSerializer(queryset)
+        expected = [
+            {'id': 1, 'name': u'target-1', 'target_source': {'id': 1, 'name': u'target-source-1', 'source': {'id': 1, 'name': u'source-1'}}},
+            {'id': 2, 'name': u'target-2', 'target_source': {'id': 2, 'name': u'target-source-2', 'source': {'id': 2, 'name': u'source-2'}}},
+            {'id': 3, 'name': u'target-3', 'target_source': None}
+        ]
+        self.assertEquals(serializer.data, expected)