Make it possible to iterate over all the known documents/records of a…

… BaseModel-derived class with persistence settings

featureflow/__init__.py

@@ -1,4 +1,4 @@
-__version__ = '1.11.10'
+__version__ = '1.12.10'
 
 from model import BaseModel
 

featureflow/model.py

@@ -25,6 +25,18 @@ def _add_features(cls, features):
             except AttributeError:
                 pass
 
+    @staticmethod
+    def _ensure_persistence_settings(cls):
+        if not issubclass(cls, PersistenceSettings):
+            raise NoPersistenceSettingsError(
+                    'The class {cls} is not a PersistenceSettings subclass'
+                    .format(cls=cls.__name__))
+
+    def __iter__(cls):
+        cls._ensure_persistence_settings(cls)
+        for _id in cls.database:
+            yield cls(_id)
+
 
 class NoPersistenceSettingsError(Exception):
     """
@@ -42,13 +54,6 @@ def __init__(self, _id=None):
         if _id:
             self._id = _id
 
-    @staticmethod
-    def _ensure_persistence_settings(cls):
-        if not issubclass(cls, PersistenceSettings):
-            raise NoPersistenceSettingsError(
-                    'The class {cls} is not a PersistenceSettings subclass'
-                        .format(cls=cls.__name__))
-
     def __getattribute__(self, key):
         f = object.__getattribute__(self, key)
 

featureflow/test_integration.py

@@ -329,6 +329,19 @@ class MultipleRoots(BaseModel):
 
 
 class BaseTest(object):
+    def test_can_iter_over_document_class(self):
+        class D(BaseModel, self.Settings):
+            stream = Feature(TextStream, store=True)
+            words = Feature(Tokenizer, needs=stream, store=False)
+            count = JSONFeature(WordCount, needs=words, store=True)
+
+        D.process(stream='mary')
+        D.process(stream='humpty')
+        D.process(stream='cased')
+
+        l = list(doc for doc in D)
+        self.assertEqual(3, len(l))
+        self.assertTrue(all(isinstance(x, D) for x in l))
 
     def test_can_use_node_that_validates_its_dependency_list(self):
         class D1(BaseModel, self.Settings):
@@ -851,6 +864,9 @@ class Doc(MultipleRoots, self.Settings):
                 KeyError,
                 lambda: Doc.process(stream1='mary'))
 
+    def test_raises_when_no_settings_base_class_and_iter_called(self):
+        self.assertRaises(NoPersistenceSettingsError, lambda: list(Document))
+
     def test_get_meaningful_error_when_no_settings_base_class_and_process_is_called(
             self):
         self.assertRaises(