Cocoa Programming for OS X: The Big Nerd Ranch Guide

Application Data and URLs

This chapter has focused on persisting data associated with the user’s documents, managed by Cocoa’s document architecture, but many applications will need to store data that is managed directly by the application. Consider a shoebox app (an app that stores collections of images, documents, notes, and so forth). Where should it store its data? What about cached data?

Data that is not related to a document has a specific home on OS X: the library. The library, or more appropriately ~/Library, is a (usually hidden) folder in the user’s home folder, as the path suggests. The library contains folders for specific purposes: Caches for cached data that can be deleted, Application Support for arbitrary data that ...