After having read Hacking with macOS I'm trying to develop another NSDocument based application. In my document (subclassed from NSDocument) I have a few properties, an enum, an int and an array of objects. The objects implement the NSCoding protocol as described in the chapter. The application also implements printing and so I would like to save/load the NSPrintInfo property (printInfo on the NSDocument base class).

My question is how should I implement my data:ofType function override to accompish saving:

• printInfo from NSDocument
• My local int and enum
• My local array of NSCoding implementing objects

In the book, NSKeyedArchiver is used but this just creates a single NSData object from a given single root object, whereas I have multiple objects to store. I could create a new data object to hold all the properties I wish to store, but then how should I refer back to the printInfo property on NSDocument?