The Core iOS Developer’s Cookbook, Fifth Edition

Practical Implementation Differences

Expect a few practical differences between building table views and collection views. Collection views are less tolerant of lazy data loading. As a rule, when you create a collection view, make sure the data source that powers that view is fully prepared to go—even if it’s prepared with a minimal or empty set of cells as you load data elsewhere in your application.

You cannot wait until your initialization or loadView or viewDidLoad methods to prepare content. Get content ready and going first, whether in your application delegate or before you instantiate and add your collection view or push a new child collection view controller. If your data is not ready to go, your app will crash; this is not the user ...