In 2009 I wrote a macOS app centered on Core Data objects. As I recall, at the time there were some issues with putting Core Data or any custom object on the Cocoa system pasteboard (NSPasteboard), and the recommended workaround was to implement your own "intra-app" pasteboard for the custom objects by overriding, for example,
-[NSOutlineView outlineView:writeItems:toPasteboard]
and similarly for pasting from the pasteboard.
In updating this app, I am warned that the above method was deprecated in macOS 11. I think the modernized solution is to delete my "intra-app" pasteboard, and instead conform my custom items to the new (to me) NSPasteboardWriting protocol, allowing them to ride on the Cocoa system pasteboard like any other serializable object – my old workaround is no longer needed.
I was hoping someone could agree with this approach before I begin the demolition. Thank you.
