How to allows songs to be rearrange in playlists using Core Data?

Question

I have created a core data model like below

Songs Core Data Attribute

Songs Core Data Relationship

Playlists Core Data

I have use this as code to pull from Core Data and arrange it with Alphabetical order.

let PlaylistTable = (PlaylistTables![0] as AnyObject).value(forKey: "songs") as! NSSet

let songsUnsorted = PlaylistTable.allObjects as NSArray
return songsUnsorted.sortedArray(using: [songSortDescriptor]) as NSArray

How can i do to allows songs to be rearrange in the order i like ? Example

a
b
c

To whatever arrangement i like and next time when i pull from Core Data it will be the same order ?

b
c
a

Answer 1

You need to add an attribute that will function as an index. That way, when you fetch, you ask for a sort descriptor that sorts on that attribute.