Here's a step-by-step guide on how to get these painful things working properly in Xcode 7.3 on OS X 10.11 El Capitan.
- Drag an
NSCollectionView
object into an existing storyboard or standalone nib. - Select the
NSCollectionView
, and in the inspector, change Layout from Content Array (Legacy) to Flow. - Configure the rest how you see fit.
- Next, add a new
NSCollectionViewItem
subclass to the project, naming it something like MyCollectionViewItem. - Check the box next to Also create XIB file for user interface. Two files will be created.