Saving Data in iOS5 Issue - ios

Question

I'm trying to save simple text data in my app using this code from Beginning iPhone Development:
- (NSString *)dataFilePath {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
return [documentsDirectory stringByAppendingFormat:kFileName];
}
- (void)applicationWillTerminate:(NSNotification *)notification {
NSMutableArray *array = [[NSMutableArray alloc] init];
[array addObject:field1.text];
[array addObject:field2.text];
[array addObject:field3.text];
[array addObject:field4.text];
[array writeToFile:[self dataFilePath] atomically:YES];
}
- (void)viewDidLoad { NSString *filePath = [self dataFilePath];
if ([[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
NSArray *array = [[NSArray alloc] initWithContentsOfFile:filePath];
field1.text = [array objectAtIndex:0];
field2.text = [array objectAtIndex:1];
field3.text = [array objectAtIndex:2];
field4.text = [array objectAtIndex:4];
}
UIApplication *app = [UIApplication sharedApplication];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(applicationWillTerminate:)
name:UIApplicationWillTerminateNotification
object:app];
[super viewDidLoad];
}
This code was written and works great for iOS 3, but not with iOS 5. If you simply tap the home button in the simulator to close it, then bring the multitasking bar up and tap on the app icon, the data reloads just fine. But, when you close it via tapping the home button, then bring up the multitasking bar and close it there as well, and relaunch the app, the data is gone. I don't think the app is getting the notification that it is being terminated when you close it from the multitasking bar, but I'm not sure about that I'm still a beginner.
I'm sure that I just need to add an extra line or 2 to the code that I already have. Does anyone know what that might be?

Answer 1

May I suggest using the NSUserDefaults class? It's very good for storing simple data like this.
Setting a value
NSUserDefaults * defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:#"value" forKey:#"field"];
[defaults synchronize];
Getting a value
NSUserDefaults * defaults = [NSUserDefaults standardUserDefaults];
NSString * value = [defaults objectForKey:#"field"]

Answer 2

My guess is that when this was written for iOS 3, applicationWillTerminate was called when you hit the home button. With iOS 5, this isn't the case. Try moving your code to -applicationDidEnterBackground.