Make library.lookup() return a list of tracks

docs/changes.rst

@@ -141,6 +141,10 @@ backends:
 - :meth:`mopidy.core.TracklistController.remove` can now remove multiple
   tracks, and returns the tracks it removed.
 
+- :meth:`mopidy.core.LibraryController.lookup` now returns a list of tracks.
+  This makes it possible to support lookup of artist or album URIs which then
+  can expand to a list of tracks.
+
 **Bug fixes**
 
 - :issue:`218`: The MPD commands ``listplaylist`` and ``listplaylistinfo`` now

mopidy/backends/dummy.py

@@ -42,9 +42,7 @@ class DummyLibraryProvider(base.BaseLibraryProvider):
         return []
 
     def lookup(self, uri):
-        matches = filter(lambda t: uri == t.uri, self.dummy_library)
-        if matches:
-            return matches[0]
+        return filter(lambda t: uri == t.uri, self.dummy_library)
 
     def refresh(self, uri=None):
         pass

mopidy/backends/local/library.py

@@ -30,10 +30,10 @@ class LocalLibraryProvider(base.BaseLibraryProvider):
 
     def lookup(self, uri):
         try:
-            return self._uri_mapping[uri]
+            return [self._uri_mapping[uri]]
         except KeyError:
             logger.debug('Failed to lookup %r', uri)
-            return None
+            return []
 
     def find_exact(self, **query):
         self._validate_query(query)

mopidy/backends/local/playlists.py

@@ -55,7 +55,7 @@ class LocalPlaylistsProvider(base.BasePlaylistsProvider):
                 try:
                     # TODO We must use core.library.lookup() to support tracks
                     # from other backends
-                    tracks.append(self.backend.library.lookup(track_uri))
+                    tracks += self.backend.library.lookup(track_uri)
                 except LookupError as ex:
                     logger.error('Playlist item could not be added: %s', ex)
 

mopidy/backends/spotify/library.py

@@ -57,10 +57,10 @@ class SpotifyLibraryProvider(base.BaseLibraryProvider):
 
     def lookup(self, uri):
         try:
-            return SpotifyTrack(uri)
+            return [SpotifyTrack(uri)]
         except SpotifyError as e:
             logger.debug('Failed to lookup "%s": %s', uri, e)
-            return None
+            return []
 
     def refresh(self, uri=None):
         pass  # TODO

mopidy/core/library.py

@@ -41,17 +41,20 @@ class LibraryController(object):
 
     def lookup(self, uri):
         """
-        Lookup track with given URI. Returns :class:`None` if not found.
+        Lookup the given URI.
+
+        If the URI expands to multiple tracks, the returned list will contain
+        them all.
 
         :param uri: track URI
         :type uri: string
-        :rtype: :class:`mopidy.models.Track` or :class:`None`
+        :rtype: list of :class:`mopidy.models.Track`
         """
         backend = self._get_backend(uri)
         if backend:
             return backend.library.lookup(uri).get()
         else:
-            return None
+            return []
 
     def refresh(self, uri=None):
         """

mopidy/frontends/mpd/protocol/current_playlist.py

@@ -22,9 +22,9 @@ def add(context, uri):
     """
     if not uri:
         return
-    track = context.core.library.lookup(uri).get()
-    if track:
-        context.core.tracklist.add(track)
+    tracks = context.core.library.lookup(uri).get()
+    if tracks:
+        context.core.tracklist.append(tracks)
         return
     raise MpdNoExistError('directory or file not found', command='add')
 
@@ -52,13 +52,19 @@ def addid(context, uri, songpos=None):
         raise MpdNoExistError('No such song', command='addid')
     if songpos is not None:
         songpos = int(songpos)
-    track = context.core.library.lookup(uri).get()
-    if track is None:
+    tracks = context.core.library.lookup(uri).get()
+    if not tracks:
         raise MpdNoExistError('No such song', command='addid')
     if songpos and songpos > context.core.tracklist.length.get():
         raise MpdArgError('Bad song index', command='addid')
-    tl_track = context.core.tracklist.add(track, at_position=songpos).get()
-    return ('Id', tl_track.tlid)
+    first_tl_track = None
+    for track in tracks:
+        tl_track = context.core.tracklist.add(track, at_position=songpos).get()
+        if songpos is not None:
+            songpos += 1
+        if first_tl_track is None:
+            first_tl_track = tl_track
+    return ('Id', first_tl_track.tlid)
 
 
 @handle_request(r'^delete "(?P<start>\d+):(?P<end>\d+)*"$')

mopidy/frontends/mpris/objects.py

@@ -279,13 +279,10 @@ class MprisObject(dbus.service.Object):
             return
         # NOTE Check if URI has MIME type known to the backend, if MIME support
         # is added to the backend.
-        uri_schemes = self.core.uri_schemes.get()
-        if not any([uri.startswith(uri_scheme) for uri_scheme in uri_schemes]):
-            return
-        track = self.core.library.lookup(uri).get()
-        if track is not None:
-            tl_track = self.core.tracklist.add(track).get()
-            self.core.playback.play(tl_track)
+        tracks = self.core.library.lookup(uri).get()
+        if tracks:
+            tl_tracks = self.core.tracklist.append(tracks).get()
+            self.core.playback.play(tl_tracks[0])
         else:
             logger.debug('Track with URI "%s" not found in library.', uri)
 

tests/backends/base/library.py

@@ -43,12 +43,12 @@ class LibraryControllerTest(object):
         pass
 
     def test_lookup(self):
-        track = self.library.lookup(self.tracks[0].uri)
-        self.assertEqual(track, self.tracks[0])
+        tracks = self.library.lookup(self.tracks[0].uri)
+        self.assertEqual(tracks, self.tracks[0:1])
 
     def test_lookup_unknown_track(self):
-        track = self.library.lookup('fake uri')
-        self.assertEquals(track, None)
+        tracks = self.library.lookup('fake uri')
+        self.assertEqual(tracks, [])
 
     def test_find_exact_no_hits(self):
         result = self.library.find_exact(track=['unknown track'])

tests/core/library_test.py

@@ -41,10 +41,10 @@ class CoreLibraryTest(unittest.TestCase):
         self.assertFalse(self.library1.lookup.called)
         self.library2.lookup.assert_called_once_with('dummy2:a')
 
-    def test_lookup_fails_for_dummy3_track(self):
+    def test_lookup_returns_nothing_for_dummy3_track(self):
         result = self.core.library.lookup('dummy3:a')
 
-        self.assertIsNone(result)
+        self.assertEqual(result, [])
         self.assertFalse(self.library1.lookup.called)
         self.assertFalse(self.library2.lookup.called)