Clean up field initialization. Fixes #497

rest_framework/serializers.py

@@ -100,7 +100,8 @@ class BaseSerializer(Field):
     _options_class = SerializerOptions
     _dict_class = SortedDictWithMetadata  # Set to unsorted dict for backwards compatibility with unsorted implementations.
 
-    def __init__(self, instance=None, data=None, files=None, context=None, partial=False, **kwargs):
+    def __init__(self, instance=None, data=None, files=None,
+                 context=None, partial=False, **kwargs):
         super(BaseSerializer, self).__init__(**kwargs)
         self.opts = self._options_class(self.Meta)
         self.parent = None
@@ -151,8 +152,6 @@ class BaseSerializer(Field):
         base_fields = copy.deepcopy(self.base_fields)
         for key, field in base_fields.items():
             ret[key] = field
-            # Set up the field
-            field.initialize(parent=self, field_name=key)
 
         # Add in the default fields
         default_fields = self.get_default_fields()
@@ -172,6 +171,10 @@ class BaseSerializer(Field):
             for key in self.opts.exclude:
                 ret.pop(key, None)
 
+        # Initialize the fields
+        for key, field in ret.items():
+            field.initialize(parent=self, field_name=key)
+
         return ret
 
     #####
@@ -186,6 +189,13 @@ class BaseSerializer(Field):
         if parent.opts.depth:
             self.opts.depth = parent.opts.depth - 1
 
+        # We need to call initialize here to ensure any nested
+        # serializers that will have already called initialize on their
+        # descendants get updated with *their* parent.
+        # We could be a bit more smart about this, but it'll do for now.
+        for key, field in self.fields.items():
+            field.initialize(parent=self, field_name=key)
+
     #####
     # Methods to convert or revert from objects <--> primitive representations.
 

rest_framework/tests/serializer.py

@@ -4,7 +4,7 @@ from django.test import TestCase
 from rest_framework import serializers
 from rest_framework.tests.models import (Album, ActionItem, Anchor, BasicModel,
     BlankFieldModel, BlogPost, Book, CallableDefaultValueModel, DefaultValueModel,
-    ManyToManyModel, Person, ReadOnlyManyToManyModel)
+    ManyToManyModel, Person, ReadOnlyManyToManyModel, Photo)
 
 
 class SubComment(object):
@@ -764,3 +764,55 @@ class DepthTest(TestCase):
                     'writer': {'id': 1, 'name': u'django', 'age': 1}}
 
         self.assertEqual(serializer.data, expected)
+
+
+class NestedSerializerContextTests(TestCase):
+
+    def test_nested_serializer_context(self):
+        """
+        Regression for #497
+
+        https://github.com/tomchristie/django-rest-framework/issues/497
+        """
+        class PhotoSerializer(serializers.ModelSerializer):
+            class Meta:
+                model = Photo
+                fields = ("description", "callable")
+
+            callable = serializers.SerializerMethodField('_callable')
+
+            def _callable(self, instance):
+                if not 'context_item' in self.context:
+                    raise RuntimeError("context isn't getting passed into 2nd level nested serializer")
+                return "success"
+
+        class AlbumSerializer(serializers.ModelSerializer):
+            class Meta:
+                model = Album
+                fields = ("photo_set", "callable")
+
+            photo_set = PhotoSerializer(source="photo_set")
+            callable = serializers.SerializerMethodField("_callable")
+
+            def _callable(self, instance):
+                if not 'context_item' in self.context:
+                    raise RuntimeError("context isn't getting passed into 1st level nested serializer")
+                return "success"
+
+        class AlbumCollection(object):
+            albums = None
+
+        class AlbumCollectionSerializer(serializers.Serializer):
+            albums = AlbumSerializer(source="albums")
+
+        album1 = Album.objects.create(title="album 1")
+        album2 = Album.objects.create(title="album 2")
+        Photo.objects.create(description="Bigfoot", album=album1)
+        Photo.objects.create(description="Unicorn", album=album1)
+        Photo.objects.create(description="Yeti", album=album2)
+        Photo.objects.create(description="Sasquatch", album=album2)
+        album_collection = AlbumCollection()
+        album_collection.albums = [album1, album2]
+
+        # This will raise RuntimeError if context doesn't get passed correctly to the nested Serializers
+        AlbumCollectionSerializer(album_collection, context={'context_item': 'album context'}).data