Implementing parent->child drill down in Cocoa with Core Data bindings that span multiple entities

Question

I\'m trying to create a simple interface to my core data model in the style of iTunes Genre browser.

I have a model setup with three entities: Genre <-->>

Answer 1

The approach I would probably take is to have a separate NSArrayController for each table view, then have the content of one array controller be based on the selection of another.

For example, say you have table view A that displays the list of available genres, so it has an array controller A whose content is hooked up to your managed object context.

Then, say you have table view B which shows the available artists for whichever genre is selected in table A. This table would have its own array controller B, and the content array for controller B is bound so the "controller key" field in IB is set to the "selection" key of controller A, with "artists" being the model key (this assumes your Genre entity has a to-many relationship named "artists" to the Artist entity).

You can then apply the same principle to a third table view + controller to show the albums for the selected artist.

The general term for this kind of setup is a "master-detail interface", and is outlined in Apple's docs at this link