item templates can use album flexattrs (fix #461)

beets/library.py

@@ -770,11 +770,12 @@ class Item(Model):
         """
         mapping = super(Item, self)._formatted_mapping(for_path)
 
-        # Override album-level fields.
+        # Merge in album-level fields.
         album = self.get_album()
         if album:
-            for key in ALBUM_KEYS_ITEM:
-                mapping[key] = album._get_formatted(key, for_path)
+            for key in album.keys(True):
+                if key in ALBUM_KEYS_ITEM or key not in ITEM_KEYS:
+                    mapping[key] = album._get_formatted(key, for_path)
 
         # Use the album artist if the track artist is not set and
         # vice-versa.

docs/changelog.rst

@@ -11,6 +11,8 @@ consequences for all users are:
   the :doc:`/plugins/inline` to define a field called ``era``, you can now
   filter your library based on that field by typing something like
   ``beet list era:goldenage``.
+* Album-level flexible attributes and plugin-provided attributes can now be
+  used in path formats (and other item-level templates).
 
 For developers, the short version of the story is that Item and Album objects
 provide *uniform access* across fixed, flexible, and computed attributes.

test/test_db.py

@@ -1022,6 +1022,28 @@ class ImportTimeTest(_common.TestCase):
         self.assertGreater(self.singleton.added, 0)
 
 
+class TemplateTest(_common.LibTestCase):
+    def album_fields_override_item_values(self):
+        self.album = self.lib.add_album([self.i])
+        self.album.albumartist = 'album-level'
+        self.album.store()
+        self.i.albumartist = 'track-level'
+        self.i.store()
+        self.assertEqual(self.i.evaluate_template('$albumartist'),
+                         'album-level')
+
+    def test_year_formatted_in_template(self):
+        self.i.year = 123
+        self.i.store()
+        self.assertEqual(self.i.evaluate_template('$year'), '0123')
+
+    def test_album_flexattr_appears_in_item_template(self):
+        self.album = self.lib.add_album([self.i])
+        self.album.foo = 'baz'
+        self.album.store()
+        self.assertEqual(self.i.evaluate_template('$foo'), 'baz')
+
+
 def suite():
     return unittest.TestLoader().loadTestsFromName(__name__)