feat(DecisionListener): Adds feature variables decision listener.

optimizely/helpers/enums.py

@@ -98,5 +98,6 @@ class NotificationTypes(object):
 
 
 class DecisionInfoTypes(object):
-    EXPERIMENT = "experiment"
-    FEATURE = "feature"
+  EXPERIMENT = "experiment"
+  FEATURE = "feature"
+  FEATURE_VARIABLE = "feature_variable"

optimizely/optimizely.py

@@ -208,8 +208,8 @@ def _get_feature_variable_for_type(self, feature_key, variable_key, variable_typ
       )
       return None
 
+    feature_enabled = False
     variable_value = variable.defaultValue
-
     decision = self.decision_service.get_variation_for_feature(feature_flag, user_id, attributes)
     if decision.variation:
 
@@ -232,12 +232,35 @@ def _get_feature_variable_for_type(self, feature_key, variable_key, variable_typ
         'Returning default value for variable "%s" of feature flag "%s".' % (user_id, variable_key, feature_key)
       )
 
+    experiment_key = None
+    variation_key = None
+
+    if decision.source == decision_service.DECISION_SOURCE_EXPERIMENT:
+      experiment_key = decision.experiment.key
+      variation_key = decision.variation.key
+
     try:
       actual_value = self.config.get_typecast_value(variable_value, variable_type)
     except:
       self.logger.error('Unable to cast value. Returning None.')
       actual_value = None
 
+    self.notification_center.send_notifications(
+      enums.NotificationTypes.DECISION,
+      enums.DecisionInfoTypes.FEATURE_VARIABLE,
+      user_id,
+      attributes or {},
+      {
+        'feature_key': feature_key,
+        'feature_enabled': feature_enabled,
+        'variable_key': variable_key,
+        'variable_value': actual_value,
+        'variable_type': variable_type,
+        'source': decision.source,
+        'source_experiment_key': experiment_key,
+        'source_variation_key': variation_key
+      }
+    )
     return actual_value
 
   def activate(self, experiment_key, user_id, attributes=None):

tests/base.py

@@ -311,24 +311,24 @@ def setUp(self, config_dict='config_dict'):
             'variables': [{
                'id': '132', 'value': 'true'
              }, {
-               'id': '135', 'value': '395'
+               'id': '133', 'value': 'Hello audience'
              }, {
                'id': '134', 'value': '39.99'
              }, {
-               'id': '133', 'value': 'Hello audience'
+               'id': '135', 'value': '399'
              }]
           }, {
             'key': '211229',
             'id': '211229',
             'featureEnabled': False,
             'variables': [{
                'id': '132', 'value': 'true'
-              }, {
-               'id': '135', 'value': '395'
              }, {
-               'id': '134', 'value': '39.99'
+               'id': '133', 'value': 'environment'
              }, {
-               'id': '133', 'value': 'Hello audience'
+               'id': '134', 'value': '49.99'
+             }, {
+               'id': '135', 'value': '499'
              }]
           }]
         }, {

tests/test_config.py

@@ -932,11 +932,11 @@ def test_get_rollout_from_id__valid_rollout_id(self):
         'variables': [{
            'id': '132', 'value': 'true'
          }, {
-           'id': '135', 'value': '395'
+           'id': '133', 'value': 'Hello audience'
          }, {
            'id': '134', 'value': '39.99'
          }, {
-           'id': '133', 'value': 'Hello audience'
+           'id': '135', 'value': '399'
          }]
       }, {
         'key': '211229',
@@ -945,11 +945,11 @@ def test_get_rollout_from_id__valid_rollout_id(self):
         'variables': [{
            'id': '132', 'value': 'true'
          }, {
-           'id': '135', 'value': '395'
+           'id': '133', 'value': 'environment'
          }, {
-           'id': '134', 'value': '39.99'
+           'id': '134', 'value': '49.99'
          }, {
-           'id': '133', 'value': 'Hello audience'
+           'id': '135', 'value': '499'
          }]
       }]
     }, {