Save and Load Data on Today Extensions (iOS 8)

Question

Is it possible to save and load data on Today Extension using NSUserDefaults? After closing the Notification Center, the widget behaves like an app which is terminated, so any data results lost. How could I solve this issue?

This is my code:

NSUserDefaults *defaults;

- (void)viewDidLoad {

[super viewDidLoad];

defaults = [NSUserDefaults standardUserDefaults];
NSArray *loadStrings = [defaults stringArrayForKey:@"savedStrings"];

if ([loadStrings objectAtIndex:0] != nil) {
    [display setText:[NSString stringWithFormat:@"%@", [loadStrings objectAtIndex:0]]];
}
if ([loadStrings objectAtIndex:1] != nil) {
    calculatorMemory = [NSString stringWithFormat:@"%@", [loadStrings objectAtIndex:1]].doubleValue;
}

}


- (IBAction)saveData:(id)sender {

NSString *displayString;
NSString *memoryString;

NSArray *saveStrings = [[NSArray alloc] initWithObjects: displayString, memoryString, nil];


defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:saveStrings forKey:@"savedStrings"];
[defaults synchronize];


}

Answer 1

You need to use app group identifier instead of com.* For instance:

NSUserDefaults *shared = [[NSUserDefaults alloc]initWithSuiteName:@"group.company.appgroup"];

Don't forget to synchronise when you store data

[shared synchronize];

Answer 2

You need to add the App Group stuff detailed under here and then if it actually worked (pretty iffy under beta) it should allow you to share NSUserDefault data like normal between the host and widget.

Edit: Normal NSUserDefaults does not work. Apple has implemented a new method. To use, simply redefine your NSUserDefaults instance like this:

NSUserDefaults *shared = [[NSUserDefaults alloc]initWithSuiteName:@"com.you.app.container"];