Introduce update config notification (#181)

optimizely/config_manager.py

@@ -21,7 +21,8 @@
 from . import exceptions as optimizely_exceptions
 from . import logger as optimizely_logger
 from . import project_config
-from .error_handler import NoOpErrorHandler as noop_error_handler
+from .error_handler import NoOpErrorHandler
+from .notification_center import NotificationCenter
 from .helpers import enums
 from .helpers import validator
 
@@ -41,7 +42,7 @@ def __init__(self,
             error_handler: Provides a handle_error method to handle exceptions.
         """
         self.logger = logger or optimizely_logger.adapt_logger(logger or optimizely_logger.NoOpLogger())
-        self.error_handler = error_handler or noop_error_handler
+        self.error_handler = error_handler or NoOpErrorHandler()
 
     @abc.abstractmethod
     def get_config(self):
@@ -57,18 +58,21 @@ def __init__(self,
                  datafile=None,
                  logger=None,
                  error_handler=None,
+                 notification_center=None,
                  skip_json_validation=False):
         """ Initialize config manager. Datafile has to be provided to use.
 
         Args:
             datafile: JSON string representing the Optimizely project.
             logger: Provides a logger instance.
             error_handler: Provides a handle_error method to handle exceptions.
+            notification_center: Notification center to generate config update notification.
             skip_json_validation: Optional boolean param which allows skipping JSON schema
                                   validation upon object invocation. By default
                                   JSON schema validation will be performed.
         """
         super(StaticConfigManager, self).__init__(logger=logger, error_handler=error_handler)
+        self.notification_center = notification_center or NotificationCenter(self.logger)
         self._config = None
         self.validate_schema = not skip_json_validation
         self._set_config(datafile)
@@ -108,8 +112,8 @@ def _set_config(self, datafile):
         if previous_revision == config.get_revision():
             return
 
-        # TODO(ali): Add notification listener.
         self._config = config
+        self.notification_center.send_notifications(enums.NotificationTypes.OPTIMIZELY_CONFIG_UPDATE)
         self.logger.debug(
             'Received new datafile and updated config. '
             'Old revision number: {}. New revision number: {}.'.format(previous_revision, config.get_revision())
@@ -135,6 +139,7 @@ def __init__(self,
                  url_template=None,
                  logger=None,
                  error_handler=None,
+                 notification_center=None,
                  skip_json_validation=False):
         """ Initialize config manager. One of sdk_key or url has to be set to be able to use.
 
@@ -148,13 +153,15 @@ def __init__(self,
                           determines URL from where to fetch the datafile.
             logger: Provides a logger instance.
             error_handler: Provides a handle_error method to handle exceptions.
+            notification_center: Notification center to generate config update notification.
             skip_json_validation: Optional boolean param which allows skipping JSON schema
                                   validation upon object invocation. By default
                                   JSON schema validation will be performed.
 
         """
         super(PollingConfigManager, self).__init__(logger=logger,
                                                    error_handler=error_handler,
+                                                   notification_center=notification_center,
                                                    skip_json_validation=skip_json_validation)
         self.datafile_url = self.get_datafile_url(sdk_key, url,
                                                   url_template or enums.ConfigManager.DATAFILE_URL_TEMPLATE)

optimizely/helpers/enums.py

@@ -119,9 +119,12 @@ class NotificationTypes(object):
       DECISION notification listener has the following parameters:
       DecisionNotificationTypes type, str user_id, dict attributes, dict decision_info
 
+      OPTIMIZELY_CONFIG_UPDATE notification listener has no associated parameters.
+
       TRACK notification listener has the following parameters:
       str event_key, str user_id, dict attributes (can be None), event_tags (can be None), Event event
   """
   ACTIVATE = 'ACTIVATE:experiment, user_id, attributes, variation, event'
   DECISION = 'DECISION:type, user_id, attributes, decision_info'
+  OPTIMIZELY_CONFIG_UPDATE = 'OPTIMIZELY_CONFIG_UPDATE'
   TRACK = 'TRACK:event_key, user_id, attributes, event_tags, event'

optimizely/optimizely.py

@@ -23,7 +23,7 @@
 from .event_dispatcher import EventDispatcher as default_event_dispatcher
 from .helpers import enums
 from .helpers import validator
-from .notification_center import NotificationCenter as notification_center
+from .notification_center import NotificationCenter
 
 
 class Optimizely(object):
@@ -70,22 +70,25 @@ def __init__(self,
       self.logger.exception(str(error))
       return
 
+    self.notification_center = NotificationCenter(self.logger)
+
     if not self.config_manager:
       if sdk_key:
         self.config_manager = PollingConfigManager(sdk_key=sdk_key,
                                                    datafile=datafile,
                                                    logger=self.logger,
                                                    error_handler=self.error_handler,
+                                                   notification_center=self.notification_center,
                                                    skip_json_validation=skip_json_validation)
       else:
         self.config_manager = StaticConfigManager(datafile=datafile,
                                                   logger=self.logger,
                                                   error_handler=self.error_handler,
+                                                  notification_center=self.notification_center,
                                                   skip_json_validation=skip_json_validation)
 
     self.event_builder = event_builder.EventBuilder()
     self.decision_service = decision_service.DecisionService(self.logger, user_profile_service)
-    self.notification_center = notification_center(self.logger)
 
   def _validate_instantiation_options(self):
     """ Helper method to validate all instantiation parameters.

tests/test_config_manager.py

@@ -28,28 +28,38 @@ def test_set_config__success(self):
         """ Test set_config when datafile is valid. """
         test_datafile = json.dumps(self.config_dict_with_features)
         mock_logger = mock.Mock()
+        mock_notification_center = mock.Mock()
         project_config_manager = config_manager.StaticConfigManager(datafile=test_datafile,
-                                                                    logger=mock_logger)
+                                                                    logger=mock_logger,
+                                                                    notification_center=mock_notification_center)
 
         project_config_manager._set_config(test_datafile)
         mock_logger.debug.assert_called_with('Received new datafile and updated config. '
                                              'Old revision number: None. New revision number: 1.')
+        mock_notification_center.send_notifications.assert_called_once_with('OPTIMIZELY_CONFIG_UPDATE')
 
     def test_set_config__twice(self):
         """ Test calling set_config twice with same content to ensure config is not updated. """
         test_datafile = json.dumps(self.config_dict_with_features)
         mock_logger = mock.Mock()
+        mock_notification_center = mock.Mock()
         project_config_manager = config_manager.StaticConfigManager(datafile=test_datafile,
-                                                                    logger=mock_logger)
+                                                                    logger=mock_logger,
+                                                                    notification_center=mock_notification_center)
 
         project_config_manager._set_config(test_datafile)
         mock_logger.debug.assert_called_with('Received new datafile and updated config. '
                                              'Old revision number: None. New revision number: 1.')
         self.assertEqual(1, mock_logger.debug.call_count)
+        mock_notification_center.send_notifications.assert_called_once_with('OPTIMIZELY_CONFIG_UPDATE')
+
+        mock_logger.reset_mock()
+        mock_notification_center.reset_mock()
 
         # Call set config again and confirm that no new log message denoting config update is there
         project_config_manager._set_config(test_datafile)
-        self.assertEqual(1, mock_logger.debug.call_count)
+        self.assertEqual(0, mock_logger.debug.call_count)
+        self.assertEqual(0, mock_notification_center.call_count)
 
     def test_set_config__schema_validation(self):
         """ Test set_config calls or does not call schema validation based on skip_json_validation value. """
@@ -78,9 +88,11 @@ def test_set_config__unsupported_datafile_version(self):
 
         test_datafile = json.dumps(self.config_dict_with_features)
         mock_logger = mock.Mock()
+        mock_notification_center = mock.Mock()
 
         project_config_manager = config_manager.StaticConfigManager(datafile=test_datafile,
-                                                                    logger=mock_logger)
+                                                                    logger=mock_logger,
+                                                                    notification_center=mock_notification_center)
 
         invalid_version_datafile = self.config_dict_with_features.copy()
         invalid_version_datafile['version'] = 'invalid_version'
@@ -90,19 +102,23 @@ def test_set_config__unsupported_datafile_version(self):
         project_config_manager._set_config(test_datafile)
         mock_logger.error.assert_called_once_with('This version of the Python SDK does not support '
                                                   'the given datafile version: "invalid_version".')
+        self.assertEqual(0, mock_notification_center.call_count)
 
     def test_set_config__invalid_datafile(self):
         """ Test set_config when datafile is invalid. """
 
         test_datafile = json.dumps(self.config_dict_with_features)
         mock_logger = mock.Mock()
+        mock_notification_center = mock.Mock()
 
         project_config_manager = config_manager.StaticConfigManager(datafile=test_datafile,
-                                                                    logger=mock_logger)
+                                                                    logger=mock_logger,
+                                                                    notification_center=mock_notification_center)
 
         # Call set_config with invalid content
         project_config_manager._set_config('invalid_datafile')
         mock_logger.error.assert_called_once_with('Provided "datafile" is in an invalid format.')
+        self.assertEqual(0, mock_notification_center.call_count)
 
     def test_get_config(self):
         """ Test get_config. """