Saving data with NSUserDetaults and load after phone restart wont work - ios

Question

I managed to save an NSMutableArray in NSUserDefaults by first converting it to NSData - I dont deal with a lot of data and just want the data to be there after I switch off & on my phone - but the data does not show up in my table where I would display it. I write the NSUserDefaults back to my array upon loading. Maybe one of you has a hint...? Below the button action where I write to NSUserDefaults and the method viewDidLoad where I write NSUserDefaults to my original array (toDoitems)
- (IBAction)unwindToList:(UIStoryboardSegue *)segue
{
XYZAddToDoItemViewController *source = [segue sourceViewController];
XYZToDoItem *item = source.toDoItem;
if (item !=nil) {
[self.toDoitems addObject:item];
NSString *error;
NSData *data = [NSPropertyListSerialization dataFromPropertyList:self.toDoitems format:NSPropertyListBinaryFormat_v1_0 errorDescription:&error];
[[NSUserDefaults standardUserDefaults] setObject:data forKey:#"itemArray"];
[[NSUserDefaults standardUserDefaults] synchronize];
[self.tableView reloadData];
}
}
- (void)viewDidLoad
{
[super viewDidLoad];
self.toDoitems = [[NSMutableArray alloc] init];
self.toDoitems = [NSMutableArray arrayWithArray:[[NSUserDefaults standardUserDefaults] objectForKey:#"itemArray"]];
}

Answer 1

Heres one way to do this
Add encoder decoder functions to your XYZToDoItem class
Something like this if say you had 2 strings in this class string1 and string2 :
(i havent compiled this code but you get the idea)
-(void)encodeWithCoder:(NSCoder *)aCoder
{
[aCoder encodeObject:self.string1 forKey:#"string1"];
[aCoder encodeObject:self.string2 forKey:#"string2"];
}
-(id)initWithCoder:(NSCoder *)aDecoder
{
self = [super init];
if (self)
{
self.string1 = [aDecoder decodeObjectForKey:#"string1"];
self.string2 = [aDecoder decodeObjectForKey:#"string2"];
}
return self;
}
Then when you are ready to save do the following
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:self.myDataArray];
[userDefaults setObject:data forKey:#"storageName"];
// To load the data from NSUserDefaults
NSData *myData = [[NSUserDefaults standardUserDefaults] objectForKey:#"storageName"];
NSArray *temp = (NSMutableArray*)[NSKeyedUnarchiver unarchiveObjectWithData:myData];
self.myDataArray = (NSMutableArray*)[temp mutableCopy];