How do you archive a plain blue cube object in osx? - macos

Question

I have a plain blue cube object in IB called AppController. Here is the header file:
//AppController.h
#import <Cocoa/Cocoa.h>
#interface AppController : NSObject <NSCoding>
#property (weak) IBOutlet NSView *view;
#property (assign) int numberOfPresses;
- (IBAction)buttonPressed:(id)sender;
#end
As you can see it has an outlet to the view, a property called numberOfPresses, and and action tied to a button in IB.
Here is the implementation file
//AppController.m
#import "AppController.h"
#implementation AppController
-(void)awakeFromNib {
NSLog(#" number of presses = %d", _numberOfPresses);
}
- (IBAction)buttonPressed:(id)sender {
_numberOfPresses++;
NSLog(#" number of presses = %d", _numberOfPresses);
}
#pragma mark - Coding Protocol
-(void)encodeWithCoder:(NSCoder *)aCoder {
[aCoder encodeInt:_numberOfPresses forKey:#"numberOfPresses"];
}
-(id)initWithCoder:(NSCoder *)aDecoder {
self = [super init];
if (self) {
_numberOfPresses = [aDecoder decodeIntForKey:#"numberOfPresses"];
}
return self;
}
#end
As you can see, when the user presses on the button, the numberOfPresses is incremented. As I quit the app and fire it up again I would like
the numberOfPresses to be remembered.
The view outlet to stil be pointing to a valid view.
Now I always get 0 for numberOfPresses, and if I try to force the archiving using NSKeyedArchiver and NSKeyedUnarchiver from AppDelegate then I end up with view = null.
This problem is a general problem of archiving plain blue cube objects from IB. But I have not found an explanation of this on the Internet, although it should be a quite common problem. I must be missing or misunderstanding something.

Answer 1

Requirement #2 should be easy. If you do nothing, then the AppController should be loaded with its view created. In a sense it is "pre-archived" for you.
That means the real problem is how to restore the number of presses.
For something that simple, NSUserDefaults is a likely candidate. Update the defaults on a press and retrieve it during awakeFromNib.
Custom archiving and unarchiving is generally better for complete custom objects that are created dynamically, rather than ones loaded from IB.
(If it was a complicated network of objects you needed to restore, I'd be talking about CoreData instead.)

Answer 2

What I was after was a GENERAL solution that I could implement in ANY project and that ONLY uses NSCoding. (If anyone has a simpler solution, I would very much like to hear it). I ended up with a solution that works, by introducing two objects: a Hub, and a RootObject. The idea can be summarized in three points:
The idea is to free all objects that you want to archive from having any presence in the IB.
Introduce a Hub object which is responsible for all IB connections. The Hub is a blue cube in IB and has an outlet to AppDelegate. The AppDelegate has an outlet to the Hub.
Introduce a RootObject whose purpose is to propagate archiving to all objects that you want to archive. The RootObject is owned by the AppDelegate. The AppDelegate is responsible for initiating the archiving and unarchiving, and the RootObject is the mediator.