I need to drag a reference to an NSManagedObject between two table views of my application. What's the preferred NSPasteboard type to store a reference to an NSManagedObject?
My current solution is to store the URIRepresentation of the object's NSManagedObjectID in a NSPasteboardTypeString. I suspect there's a more elegant solution out there.
There is no standard type for all model objects since your model objects and how they're handled are unique to your application. If there was one pasteboard type for all then there'd be no telling them apart. Your own custom object should have its own drag type.
Just use a string that makes sense (maybe a #define so you can find it with auto-complete in Xcode) like "MyObjectPboardType" that resolves to "com.yourcompany.yourapp.yourobjecttype".
Use NSPasteboard's -declareTypes:owner: to declare your new type, then use -setString:forType: or one of the other -set?:forType: methods to set the information for your object's type. In your case, the use of the object ID is a perfectly acceptable identifier. Just remember managed objects' object IDs change when they're new versus persisted.