newitem: support multiple depth inheritance of ItemAdaptor

--HG--
extra : convert_revision : svn%3Ab85faa78-f9eb-468e-a121-7cced6da292c%40929

scrapy/trunk/scrapy/contrib_exp/newitem/adaptors.py

@@ -15,14 +15,16 @@ class ItemAdaptor(object):
     def _get_field_adaptors(self):
         def get_field_adaptor(field, cls):
             if field in cls.__dict__:
-                fa[field] = cls.__dict__[field]
+                return cls.__dict__[field]
+            else:
+                for class_ in cls.__bases__:
+                    return get_field_adaptor(field, class_)
 
         fa = {}
         for field in self.item_instance._fields.keys():
-            for base in self.__class__.__bases__:
-                get_field_adaptor(field, base)
-
-            get_field_adaptor(field, self.__class__)
+            adaptor = get_field_adaptor(field, self.__class__)
+            if adaptor:
+                fa[field] = adaptor
 
         return fa
 

scrapy/trunk/scrapy/tests/test_itemadaptor.py

@@ -7,6 +7,7 @@ from scrapy.contrib_exp.newitem import Item, StringField
 class TestItem(Item):
     name = StringField()
     url = StringField()
+    summary = StringField()
 
 class TestAdaptor(ItemAdaptor):
     item_class = TestItem
@@ -30,6 +31,15 @@ class ItemAdaptorTest(unittest.TestCase):
         assert 'name' in ia._field_adaptors
 
 
+        class ChildChildTestAdaptor(ChildTestAdaptor):
+            summary = lambda v, adaptor_args: v
+
+        ia = ChildChildTestAdaptor()
+        assert 'url' in ia._field_adaptors
+        assert 'name' in ia._field_adaptors
+        assert 'summary' in ia._field_adaptors
+
+
         ia.url = 'HTTP://scrapy.ORG'
         self.assertEqual(ia.url, 'http://scrapy.org')