From 94cd1369437f84adefb46462439b46dc5208ab1d Mon Sep 17 00:00:00 2001
From: Craig de Stigter
Date: Thu, 29 Aug 2013 17:35:15 +1200
Subject: add transform_<fieldname> methods to serializers, which basically do
 the opposite of validate_<fieldname> on a per-field basis.

---
 rest_framework/serializers.py | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'rest_framework')

diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index 31cfa344..8ba1b195 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -304,6 +304,9 @@ class BaseSerializer(WritableField):
             field.initialize(parent=self, field_name=field_name)
             key = self.get_field_key(field_name)
             value = field.field_to_native(obj, field_name)
+            method = getattr(self, 'transform_%s' % field_name, None)
+            if callable(method):
+                value = method(obj, value)
             ret[key] = value
             ret.fields[key] = field
         return ret
-- 
cgit v1.2.3


From dc650f77b5f377bbfab3da66455feb57b195a1da Mon Sep 17 00:00:00 2001
From: Craig de Stigter
Date: Thu, 3 Oct 2013 11:34:42 +1300
Subject: add tests for transform_fieldname methods

---
 rest_framework/tests/test_serializer.py | 35 +++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

(limited to 'rest_framework')

diff --git a/rest_framework/tests/test_serializer.py b/rest_framework/tests/test_serializer.py
index c2497660..ca876eae 100644
--- a/rest_framework/tests/test_serializer.py
+++ b/rest_framework/tests/test_serializer.py
@@ -1643,3 +1643,38 @@ class SerializerSupportsManyRelationships(TestCase):
         serializer = SimpleSlugSourceModelSerializer(data={'text': 'foo', 'targets': [1, 2]})
         self.assertTrue(serializer.is_valid())
         self.assertEqual(serializer.data, {'text': 'foo', 'targets': [1, 2]})
+
+
+class TransformMethodsSerializer(serializers.Serializer):
+    a = serializers.CharField()
+    b_renamed = serializers.CharField(source='b')
+
+    def transform_a(self, obj, value):
+        return value.lower()
+
+    def transform_b_renamed(self, obj, value):
+        if value is not None:
+            return 'and ' + value
+
+
+class TestSerializerTransformMethods(TestCase):
+    def setUp(self):
+        self.s = TransformMethodsSerializer()
+
+    def test_transform_methods(self):
+        self.assertEqual(
+            self.s.to_native({'a': 'GREEN EGGS', 'b': 'HAM'}),
+            {
+                'a': 'green eggs',
+                'b_renamed': 'and HAM',
+            }
+        )
+
+    def test_missing_fields(self):
+        self.assertEqual(
+            self.s.to_native({'a': 'GREEN EGGS'}),
+            {
+                'a': 'green eggs',
+                'b_renamed': None,
+            }
+        )
-- 
cgit v1.2.3