+playlist.search( name ): filter the playlist items with the given string
+playlist.current(): return the current input item
+playlist.sort( key ): sort the playlist according to the key.
+ Key must be one of the followings values: 'id', 'title', 'title nodes first',
+ 'artist', 'genre', 'random', 'duration',
+ 'title numeric' or 'album'.
+playlist.status(): return the playlist status: 'stopped', 'playing', 'paused' or 'unknown'.