MPFeedbackCommand

The shared MPRemoteCommandCenter object vends feedback objects for liking, disliking, and bookmarking media items. Use these objects to register handlers for the types of feedback your app supports and to perform the appropriate tasks when that feedback changes. When the currently playing item changes, you can also use this object to set the feedback state for the new item.

When the state of a feedback item changes, the system delivers an appropriate event to registered handlers of this object. Your handler code must determine which media item receives the feedback and then apply the update the feedback state for that item. You might also perform other tasks related to receiving feedback. For example, if the user likes the currently playing song, you might update the appropriate UI in your app or use the information to recommend similar songs.