Saving strings in user prefs file

Question

Hi all,
I'm experimenting with user preferences. The IB interface works okay, and the panel appears when selected from the 'Preferences...' menu item. I do have one slight issue with it, but I'll deal with that as a separate question later.
In the meantime, I just want to store (1) a name string and (2) an address string , but all the example code I've been able to find has dealt with storing data objects only. Now if I've got this right NSStrings don't need to be stored as objects, so how do I modify my code to achieve this?
Here's my 'PrefsController' header file:
// PrefsController.h
#import <Cocoa/Cocoa.h>
extern NSString *nameKey;
extern NSString *addressKey;
@interface PrefsController : NSWindowController
IBOutlet NSTextField *nameField;
IBOutlet NSTextField *addressField;
<snip>
@end
...my 'PrefsController' main file:
// PrefsController.m
#import "PrefsController.h"
NSString *nameKey = @"name";
NSString *addressKey = @"address";
@implementation PrefsController
-(id)init
self = [super initWithWindowNibName:@"Preferences"];
return self;
<snip>
@end
...and finally, my 'AppController' main file, where the problem lies:
// AppController.m
#import "AppController.h"
#import "PrefsController.h"
@implementation AppController
+ (void) initialize
// Create a (mutable?) dictionary
NSMutableDictionary *defaultValues = [NSMutableDictionary dictionary];
//••• usual place for NSData object below •••
//••• place for unknown default values below •••
[first default value];
[second default value];
// Register the default dictionary
[[NSUserDefaults standardUserDefaults] registerDefaults: defaultValues];
NSLog(@"registered defaults: %@", defaultValues);
<snip>
@end
As you can see, the problem is in AppController.m, with (1) the omission of an NSData object, and (2) the unknown default values required.
Since this test app will never be asked to do more than swap two strings, another thing I'm curious to learn is if I could use a plain NSDictionary instead of a mutable one?
Any help would be much appreciated. Thanks!
Ernie

Answer 1

Hehehe..... Thanks again, phunkjoker. The bindings fixed this issue in seconds! The prefs function is now creating a file in Library/Preferences/ and saving and retrieving strings. Dammit, I love this Cocoa.
While all the demo code I've managed to find makes no mention of Shared User Defaults, I can see how useful (even critical) this is, but realise such 'refinements' probably won't find their way into bare-bones examples.
Unfortunately, because I've been on such a roll with the practical stuff I've far outpaced my understanding of Cocoa theory, and will spend the next few days going through the docs -- in particular, the ones you listed. In one way, getting ahead of myself is good because the material is going to make a lot more sense as I read it. Also understood what you said about the '+' initializer.
In the meantime, I actually do have two much smaller issues remaining...
(1) The prefs panel has two NSTextFields labelled 'email' and 'login' respectively (required for ID as part of a header in my text file output, rather than indicating any grandiose plans on my part to mess in these areas). I noticed that in order for any changes to be saved, I must subsequently click or tab *out of the box* again (into the remaining field) before quitting out.
(2) The example app I followed has no 'Okay' button, and therefore no means of disposing of the prefs panel other than quitting. Now, after much searching, the most likely candidate I found was orderOut:. Putting this in my 'prefsController.m' file as an 'Okay' button action, I have:
-(IBAction)okayPrefs:(id)sender
NSBeep(); // my code required here
[window orderOut:self]; //••• experimental
As it stands, the build fails due to 'error: 'window' undeclared (first use in this function)'. Declaring 'window' in 'prefsController.h' like this:
@interface PrefsController : NSWindowController
IBOutlet NSTextField *emailField;
IBOutlet NSTextField *loginField;
IBOutlet NSPanel *window; //••• experimental
-(IBAction)okayPrefs:(id)sender;
-(IBAction)cancelPrefs:(id)sender;
@end
...allows it to build successfully, but has no effect when I click the button. Any guidance on these items please, or should I float them in a separate post?
Ernie