Add get_by_id() and get_by_uri() to BaseCurrentPlaylistController

docs/api/backends.rst

@@ -52,6 +52,20 @@
 
         Clear the current playlist.
 
+    .. method:: get_by_id(id)
+
+        Get track by ID. Raises :class:`KeyError` if not found.
+
+        :param id: track ID
+        :type id: int
+
+    .. method:: get_by_uri(uri)
+
+        Get track by URI. Raises :class:`KeyError` if not found.
+
+        :param uri: track URI
+        :type uri: string
+
     .. method:: load(playlist)
 
         Replace the current playlist with the given playlist.

mopidy/backends/__init__.py

@@ -37,6 +37,20 @@ class BaseCurrentPlaylistController(object):
         self.backend.playback.stop()
         self.playlist = Playlist()
 
+    def get_by_id(self, id):
+        matches = filter(lambda t: t.id == id, self._playlist.tracks)
+        if matches:
+            return matches[0]
+        else:
+            raise KeyError('Track with ID "%s" not found' % id)
+
+    def get_by_uri(self, uri):
+        matches = filter(lambda t: t.uri == uri, self._playlist.tracks)
+        if matches:
+            return matches[0]
+        else:
+            raise KeyError('Track with URI "%s" not found' % uri)
+
     def load(self, playlist):
         self.playlist = playlist
         self.version = 0