The majority of Core Data sample code is for either single-window applications or single-document-window applications. There are, however, times when an application or document requires more than one window on its data. When starting out learning to write code with Core Data, I spent a great deal of time trying to find a tutorial that covered multi-window applications; aside from Apple’s CoreRecipes application (which I found rather frightening to disassemble), there is very little reference information ‘out there’.
In this article I aim to show the way I code multi-window Cocoa data apps. I am by no means trying to say how all such code should be written and I definitely don’t claim that what I am currently doing is absolutely the best way to do things. Hopefully the article may help someone else who is beginning to write a multi-window Core Data application. Please accept my apologies if it is written at a level below your own knowledge; on the other hand if it assumes too much or you don’t understand something, feel free to contact me and ask.