music_kraken/objects/collection.py

@@ -36,6 +36,7 @@ class Collection(Generic[T]):
         # Value: main collection to sync to
         self.contain_given_in_attribute: Dict[str, Collection] = contain_given_in_attribute or {}
         self.append_object_to_attribute: Dict[str, T] = append_object_to_attribute or {}
+        self.sync_on_append: Dict[str, Collection] = sync_on_append or {}
 
         self._id_to_index_values: Dict[int, set] = defaultdict(set)
         self._indexed_values = defaultdict(lambda: None)
@@ -229,6 +230,11 @@ class Collection(Generic[T]):
 
             for attribute, new_object in self.append_object_to_attribute.items():
                 __object.__getattribute__(attribute).append(new_object)
+            
+            for attribute, collection in self.sync_on_append.items():
+                collection.extend(__object.__getattribute__(attribute))
+                __object.__setattr__(attribute, collection)
+
         else:
             # merge only if the two objects are not the same
             if existing_object.id == __object.id:

music_kraken/objects/song.py

@@ -91,6 +91,10 @@ class Song(Base):
             "artist_collection": self.main_artist_collection,
         }
         """
+        self.album_collection.sync_on_append = {
+            "artist_collection": self.main_artist_collection,
+        }
+
         self.album_collection.append_object_to_attribute = {
             "song_collection": self,
         }
@@ -247,7 +251,7 @@ class Album(Base):
         self.song_collection.append_object_to_attribute = {
             "album_collection": self
         }
-        self.song_collection.contain_given_in_attribute = {
+        self.song_collection.sync_on_append = {
             "main_artist_collection": self.artist_collection
         }