#291: plugin hook for track_for_id

For symmetry with album candidates, plugins can now provide item candidates by
ID.

beets/autotag/hooks.py

@@ -182,12 +182,20 @@ def _album_for_id(album_id):
     return filter(None, candidates)
 
 def _track_for_id(track_id):
-    """Get an item for a recording MBID."""
+    """Get an item for a recording ID."""
+    candidates = []
+
+    # From MusicBrainz.
     try:
-        return mb.track_for_id(track_id)
+        candidates.append(mb.track_for_id(track_id))
     except mb.MusicBrainzAPIError as exc:
         exc.log(log)
 
+    # From plugins.
+    candidates.extend(plugins.track_for_id(track_id))
+
+    return filter(None, candidates)
+
 def _album_candidates(items, artist, album, va_likely):
     """Search for album matches. ``items`` is a list of Item objects
     that make up the album. ``artist`` and ``album`` are the respective

beets/autotag/match.py

@@ -544,8 +544,7 @@ def tag_item(item, search_artist=None, search_title=None,
     trackid = search_id or item.mb_trackid
     if trackid:
         log.debug('Searching for track ID: ' + trackid)
-        track_info = hooks._track_for_id(trackid)
-        if track_info:
+        for track_info in hooks._track_for_id(trackid):
             dist = track_distance(item, track_info, incl_artist=True)
             candidates[track_info.track_id] = \
                     hooks.TrackMatch(dist, track_info)

beets/autotag/mb.py

@@ -330,7 +330,6 @@ def _parse_id(s):
     match = re.search('[a-f0-9]{8}(-[a-f0-9]{4}){3}-[a-f0-9]{12}', s)
     if match:
         return match.group()
-    log.error('Invalid MBID.')
 
 def album_for_id(albumid):
     """Fetches an album by its MusicBrainz ID and returns an AlbumInfo
@@ -339,6 +338,7 @@ def album_for_id(albumid):
     """
     albumid = _parse_id(albumid)
     if not albumid:
+        log.error('Invalid MBID.')
         return
     try:
         res = musicbrainzngs.get_release_by_id(albumid,
@@ -357,6 +357,7 @@ def track_for_id(trackid):
     """
     trackid = _parse_id(trackid)
     if not trackid:
+        log.error('Invalid MBID.')
         return
     try:
         res = musicbrainzngs.get_recording_by_id(trackid, TRACK_INCLUDES)

beets/plugins.py

@@ -102,8 +102,14 @@ class BeetsPlugin(object):
         return {}
 
     def album_for_id(self, album_id):
-        """Should return an AlbumInfo object or None if no matching release
-        was found.
+        """Return an AlbumInfo object or None if no matching release was
+        found.
+        """
+        return None
+
+    def track_for_id(self, track_id):
+        """Return a TrackInfo object or None if no matching release was
+        found.
         """
         return None
 
@@ -282,6 +288,16 @@ def album_for_id(album_id):
             out.append(res)
     return out
 
+def track_for_id(track_id):
+    """Get TrackInfo objects for a given ID string.
+    """
+    out = []
+    for plugin in find_plugins():
+        res = plugin.track_for_id(track_id)
+        if res:
+            out.append(res)
+    return out
+
 def configure(config):
     """Sends the configuration object to each plugin."""
     for plugin in find_plugins():