Move SmartArtistSort to library (#953)

Models can now have a dict of special sort classes.

beets/dbcore/db.py

@@ -124,6 +124,11 @@ class Model(object):
     """Optional Types for non-fixed (i.e., flexible and computed) fields.
     """
 
+    _sorts = {}
+    """Optional named sort criteria. The keys are strings and the values
+    are subclasses of `Sort`.
+    """
+
     @classmethod
     def _getters(cls):
         """Return a mapping from field names to getter functions.

beets/dbcore/query.py

@@ -619,25 +619,6 @@ class FixedFieldSort(FieldSort):
         return "{0} {1}".format(self.field, order)
 
 
-class SmartArtistSort(Sort):
-    """Sort by artist (either album artist or track artist),
-    prioritizing the sort field over the raw field.
-    """
-    def __init__(self, model_cls, is_ascending=True):
-        self.model_cls = model_cls
-        self.is_ascending = is_ascending
-
-    def order_clause(self):
-        order = "ASC" if self.is_ascending else "DESC"
-        if 'albumartist' in self.model_cls._fields:
-            field = 'albumartist'
-        else:
-            field = 'artist'
-        return ('(CASE {0}_sort WHEN NULL THEN {0} '
-                'WHEN "" THEN {0} '
-                'ELSE {0}_sort END) {1}').format(field, order)
-
-
 class SlowFieldSort(FieldSort):
     """A sort criterion by some model field other than a fixed field:
     i.e., a computed or flexible field.

beets/dbcore/queryparse.py

@@ -136,11 +136,10 @@ def construct_sort_part(model_cls, part):
     assert direction in ('+', '-'), "part must end with + or -"
     is_ascending = direction == '+'
 
-    if field in model_cls._fields:
+    if field in model_cls._sorts:
+        sort = model_cls._sorts[field](model_cls, is_ascending)
+    elif field in model_cls._fields:
         sort = query.FixedFieldSort(field, is_ascending)
-    elif field == 'smartartist':
-        # Special case for smart artist sort.
-        sort = query.SmartArtistSort(model_cls, is_ascending)
     else:
         # Flexible or computed.
         sort = query.SlowFieldSort(field, is_ascending)

beets/library.py

@@ -60,7 +60,6 @@ class PathQuery(dbcore.FieldQuery):
 
 # Library-specific field types.
 
-
 class DateType(types.Float):
     # TODO representation should be `datetime` object
     # TODO distinguish beetween date and time types
@@ -144,6 +143,27 @@ class MusicalKey(types.String):
             return self.parse(key)
 
 
+# Library-specific sort types.
+
+class SmartArtistSort(dbcore.query.Sort):
+    """Sort by artist (either album artist or track artist),
+    prioritizing the sort field over the raw field.
+    """
+    def __init__(self, model_cls, is_ascending=True):
+        self.model_cls = model_cls
+        self.is_ascending = is_ascending
+
+    def order_clause(self):
+        order = "ASC" if self.is_ascending else "DESC"
+        if 'albumartist' in self.model_cls._fields:
+            field = 'albumartist'
+        else:
+            field = 'artist'
+        return ('(CASE {0}_sort WHEN NULL THEN {0} '
+                'WHEN "" THEN {0} '
+                'ELSE {0}_sort END) {1}').format(field, order)
+
+
 # Special path format key.
 PF_KEY_DEFAULT = 'default'
 
@@ -347,6 +367,8 @@ class Item(LibModel):
 
     _formatter = FormattedItemMapping
 
+    _sorts = {'smartartist': SmartArtistSort}
+
     @classmethod
     def _getters(cls):
         getters = plugins.item_field_getters()
@@ -710,6 +732,8 @@ class Album(LibModel):
 
     _search_fields = ('album', 'albumartist', 'genre')
 
+    _sorts = {'smartartist': SmartArtistSort}
+
     item_keys = [
         'added',
         'albumartist',

test/test_dbcore.py

@@ -25,6 +25,10 @@ from tempfile import mkstemp
 # Fixture: concrete database and model classes. For migration tests, we
 # have multiple models with different numbers of fields.
 
+class TestSort(dbcore.query.FieldSort):
+    pass
+
+
 class TestModel1(dbcore.Model):
     _table = 'test'
     _flex_table = 'testflex'
@@ -35,6 +39,9 @@ class TestModel1(dbcore.Model):
     _types = {
         'some_float_field': dbcore.types.FLOAT,
     }
+    _sorts = {
+        'some_sort': TestSort,
+    }
 
     @classmethod
     def _getters(cls):
@@ -455,6 +462,10 @@ class SortFromStringsTest(unittest.TestCase):
         self.assertIsInstance(s, dbcore.query.MultipleSort)
         self.assertIsInstance(s.sorts[0], dbcore.query.SlowFieldSort)
 
+    def test_special_sort(self):
+        s = self.sfs(['some_sort+'])
+        self.assertIsInstance(s.sorts[0], TestSort)
+
 
 def suite():
     return unittest.TestLoader().loadTestsFromName(__name__)