Merge pull request #3831 from dosoe/beets_tag_hook

Add two events extracting_trackdata and extracting_albumdata

beets/autotag/mb.py

@@ -23,6 +23,7 @@ import traceback
 from six.moves.urllib.parse import urljoin
 
 from beets import logging
+from beets import plugins
 import beets.autotag.hooks
 import beets
 from beets import util
@@ -265,6 +266,11 @@ def track_info(recording, index=None, medium=None, medium_index=None,
     if arranger:
         info.arranger = u', '.join(arranger)
 
+    # Supplementary fields provided by plugins
+    extra_trackdatas = plugins.send('mb_track_extract', data=recording)
+    for extra_trackdata in extra_trackdatas:
+        info.update(extra_trackdata)
+
     info.decode()
     return info
 
@@ -453,6 +459,10 @@ def album_info(release):
     if config['musicbrainz']['genres'] and genres:
         info.genre = ';'.join(g['name'] for g in genres)
 
+    extra_albumdatas = plugins.send('mb_album_extract', data=release)
+    for extra_albumdata in extra_albumdatas:
+        info.update(extra_albumdata)
+
     info.decode()
     return info
 

docs/changelog.rst

@@ -204,6 +204,8 @@ Other new things:
   configuration.
   Thanks to :user:`FichteFoll`.
   :bug:`2797` :bug:`2988`
+* Add ``mb_album_extract`` and ``mb_track_extract`` hooks to allow
+  plugins to add new fields based on MusicBrainz data. Thanks to :user:`dosoe`.
 * Removes usage of the bs1770gain replaygain backend.
   Thanks to :user:`SamuelCook`.
 * Added ``trackdisambig`` which stores the recording disambiguation from
@@ -2007,7 +2009,7 @@ Major new features and bigger changes:
   search results you wish to see when looking up releases at MusicBrainz
   during import. :bug:`1245`
 * The importer now records the data source for a match in a new
-  flexible attribute `data_source` on items and albums. :bug:`1311`
+  flexible attribute ``data_source`` on items and albums. :bug:`1311`
 * The colors used in the terminal interface are now configurable via the new
   config option ``colors``, nested under the option ``ui``. (Also, the `color`
   config option has been moved from top-level to under ``ui``. Beets will

docs/dev/plugins.rst

@@ -245,6 +245,18 @@ The events currently available are:
   during a ``beet import`` interactive session. Plugins can use this event for
   :ref:`appending choices to the prompt <append_prompt_choices>` by returning a
   list of ``PromptChoices``. Parameters: ``task`` and ``session``.
+  
+* `mb_track_extract`: called after the metadata is obtained from
+  MusicBrainz. The parameter is a ``dict`` containing the tags retrieved from
+  MusicBrainz for a track. Plugins must return a new (potentially empty)
+  ``dict`` with additional ``field: value`` pairs, which the autotagger will
+  apply to the item, as flexible attributes if ``field`` is not a hardcoded
+  field. Fields already present on the track are overwritten. 
+  Parameter: ``data``
+
+* `mb_album_extract`: Like `mb_track_extract`, but for album tags. Overwrites
+  tags set at the track level, if they have the same ``field``.
+  Parameter: ``data``
 
 The included ``mpdupdate`` plugin provides an example use case for event listeners.