Overhaul how queryless all() works.

switchboard/models.py

@@ -156,43 +156,36 @@ def remove(cls, key):
 
     @classmethod
     def all(cls):
-        if cls._is_redis_datastore():
-            return cls._redis_all()
-        else:
-            query = datastore.Query(_key())
-            return [cls(**data) for data in cls.ds.query(query)]
-
-    @classmethod
-    def _is_redis_datastore(cls):
-        '''
-        Check to see if the datastore is Redis.
-        '''
+        query = datastore.Query(_key())
         try:
-            import datastore.redis
-        except ImportError:
-            return False
-        return isinstance(cls.ds, datastore.redis.RedisDatastore)
+            results = cls.ds.query(query)
+        except NotImplementedError:
+            results = cls._queryless_all()
+        return [cls(**result) for result in results]
 
     @classmethod
-    def _redis_all(cls):
+    def _queryless_all(cls):
         '''
-        This is a hack because Datastore's Redis layer doesn't support
-        querying.
+        This is a hack because some datastore implementations don't support
+        querying. Right now the solution is to drop down to the underlying
+        native client and query all, which means that this section is ugly.
+        If it were architected properly, you might be able to do something
+        like inject an implementation of a NativeClient interface, which would
+        let Switchboard users write their own NativeClient wrappers that
+        implement all. However, at this point I'm just happy getting datastore
+        to work, so quick-and-dirty will suffice.
         '''
-        r = cls.ds._redis
-        keys = r.keys()
-        # Need to deserialize.
-        serializer = cls.ds.child_datastore.serializer
-
-        def get_instance(k):
-            value = r.get(k)
-            if value is None:
-                return value
-            else:
-                deserialized_value = serializer.loads(value)
-                return cls(**deserialized_value)
-
-        return [get_instance(k) for k in keys]
+        if hasattr(cls.ds, '_redis'):
+            r = cls.ds._redis
+            keys = r.keys()
+            serializer = cls.ds.child_datastore.serializer
+
+            def get_value(k):
+                value = r.get(k)
+                return value if value is None else serializer.loads(value)
+            return [get_value(k) for k in keys]
+        else:
+            raise NotImplementedError
 
     @classmethod
     def drop(cls):