backends: Add BackendListener.on_event()

mopidy/backends/listener.py

@@ -21,7 +21,20 @@ class BackendListener(object):
         """Helper to allow calling of backend listener events"""
         listeners = pykka.ActorRegistry.get_by_class(BackendListener)
         for listener in listeners:
-            getattr(listener.proxy(), event)(**kwargs)
+            listener.proxy().on_event(event, **kwargs)
+
+    def on_event(self, event, **kwargs):
+        """
+        Called on all events.
+
+        *MAY* be implemented by actor. By default, this method forwards the
+        event to the specific event methods.
+
+        :param event: the event name
+        :type event: string
+        :param kwargs: any other arguments to the specific event handlers
+        """
+        getattr(self, event)(**kwargs)
 
     def playlists_loaded(self):
         """

tests/backends/listener_test.py

@@ -1,13 +1,22 @@
 from __future__ import unicode_literals
 
+import mock
+
 from mopidy.backends.listener import BackendListener
 
 from tests import unittest
 
 
-class CoreListenerTest(unittest.TestCase):
+class BackendListenerTest(unittest.TestCase):
     def setUp(self):
         self.listener = BackendListener()
 
+    def test_on_event_forwards_to_specific_handler(self):
+        self.listener.playlists_loaded = mock.Mock()
+
+        self.listener.on_event('playlists_loaded')
+
+        self.listener.playlists_loaded.assert_called_with()
+
     def test_listener_has_default_impl_for_playlists_loaded(self):
         self.listener.playlists_loaded()