Here's how I'm doing it in an app I'm writing:
I have an abstract entity called AbstractGroup, which has a string
attribute called "name", a number attribute called "weight", and a
method stub that returns an NSSet * called "items".
AbstractGroup has two subclasses: AbstractSmartGroup and Gr
How would you model "smart playlists" (like in iTunes) with Core Data?
If you have a Song entity, it is fairly obvious how you model a "regular
playlist". The RegularPlaylist entity would simply have a to-many relationship
to the Song entity, being a simple collection of songs that the user ad
