NSUserDefault can't save & load in Extension in iOS8 - ios

Question

I need to save data to NSUserDefault in my iOS Custom Keyboard.
I have successfully created App Groups and entitlement in developer portal and XCode.
Here is how i save my value with UISwitch
- (IBAction)switchAction:(id)sender
{
[self.defaults setBool:self.myKey.on forKey:#"myValue"];
[self.defaults synchronize];
}
and here is how i load value in KeyboardView.
self.defaults = [[NSUserDefaults alloc] initWithSuiteName:#"group.mycompany.customkeyboard"];
if([self.defaults boolForKey:#"myValue"])
{
self.backgroundColor = [UIColor redColor];
}
else
{
self.backgroundColor = [UIColor blackColor];
}
It's doesn't work and doesn't load value.
How can i save and load data?

Answer 1

Initialize your NSUserDefaults object like this in all applications in the app group and they will share the database:
[[NSUserDefaults alloc] initWithSuiteName:#"group identifier"];
Keep in mind everything from the [NSUserDefaults standardUserDefaults] database for each application will not carry over into this database.
The documentation indicates that [NSUserDefaults standardUserDefaults] should return the shared database like the above code does, however it does not. I filed this as a bug (rdar://17164758).
And don't forget to synchronize the database:
[yourDefaults synchronize];

Answer 2

Ok, So I had a look around becuase I had the exact problem. What I did that worked was to add the main app and the extension to a group, Go to main project->Target->Capabilities and create a group (if you don't have one, or make one anyway) like this:
Then, go to the Extension below the target (E), again to Capabilities and add the extension to the group (exactly the same app group as you did for the main target), like this:
Then, once you have done both, in your main app, whenever you want to add something, create a new instance of NSUserDefaults, but for the Suitename equal to the groupname you made earlier. Like this:
NSArray *testing = #[#"first",#"Second",#"Third"];
NSUserDefaults *userd = [[NSUserDefaults alloc]initWithSuiteName:#"The gouprname I made earlier"];//This is exactly the same as the groupname
[userd setObject:testing forKey:#"ExtensionArray"];//set the object you want to share
[userd synchronize]; //It's a good idea to sync, just to be on the safe side.
In your extension's ViewController, use the same group name but to read the user defaults:
NSUserDefaults *sharedD=[[NSUserDefaults alloc]initWithSuiteName:#"Exactly the same groupname that I gave both in the Capabilities and when initialising the userdefault"];
self.testing = [[NSArray alloc]initWithArray:[sharedD arrayForKey:#"ExtensionArray"]];
And Voila! the array is there! I read somewhere that you can even add notification functionality for when the object changes, using a Wormhole class, but I can't find the link to it. I'm sure if you google for Wormhole class, you'll come across it.
I hope I could help, and if you found any more info, please share it with me.

Answer 3

You could load the right data from the containing app, so maybe set a new value in extension app will help.
[self.defaults setObject:newValue forKey:#"thisKeyIsJustUsedForSyn"]
And then load the right data.