Allow custom replacements in Item.destination

This allows for the use of differing replacements for destinations other than
the library, which is useful for beets-alternatives in the case where
filesystem requirements differ between the two paths.

Signed-off-by: Christopher Larson <kergoth@gmail.com>

beets/library.py

@@ -938,7 +938,7 @@ class Item(LibModel):
     # Templating.
 
     def destination(self, fragment=False, basedir=None, platform=None,
-                    path_formats=None):
+                    path_formats=None, replacements=None):
         """Returns the path in the library directory designated for the
         item (i.e., where the file ought to be). fragment makes this
         method return just the path fragment underneath the root library
@@ -950,6 +950,8 @@ class Item(LibModel):
         platform = platform or sys.platform
         basedir = basedir or self._db.directory
         path_formats = path_formats or self._db.path_formats
+        if replacements is None:
+            replacements = self._db.replacements
 
         # Use a path format based on a query, falling back on the
         # default.
@@ -994,7 +996,7 @@ class Item(LibModel):
             maxlen = util.max_filename_length(self._db.directory)
 
         subpath, fellback = util.legalize_path(
-            subpath, self._db.replacements, maxlen,
+            subpath, replacements, maxlen,
             os.path.splitext(self.path)[1], fragment
         )
         if fellback:

docs/changelog.rst

@@ -36,6 +36,11 @@ Other new things:
 * :doc:`/plugins/unimported`: Support excluding specific
   subdirectories in library.
 
+For plugin developers:
+
+* :py:meth:`beets.library.Item.destination` now accepts a `replacements`
+  argument to be used in favor of the default.
+
 Bug fixes:
 
 * :doc:`/plugins/lyrics`: Fix crash bug when beautifulsoup4 is not installed.

test/test_library.py

@@ -449,6 +449,16 @@ class DestinationTest(_common.TestCase):
         self.assertEqual(self.i.destination(),
                          np('base/ber/foo'))
 
+    def test_destination_with_replacements_argument(self):
+        self.lib.directory = b'base'
+        self.lib.replacements = [(re.compile(r'a'), 'f')]
+        self.lib.path_formats = [('default', '$album/$title')]
+        self.i.title = 'foo'
+        self.i.album = 'bar'
+        replacements = [(re.compile(r'a'), 'e')]
+        self.assertEqual(self.i.destination(replacements=replacements),
+                         np('base/ber/foo'))
+
     @unittest.skip('unimplemented: #359')
     def test_destination_with_empty_component(self):
         self.lib.directory = b'base'