Saving data with NSUserDetaults and load after phone restart wont work

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"]];
}

Shouldn't this: `[self.tableView reloadData];` be in viewDidAppear in your `XYZAddToDoItemViewController`? And after you set: `self.toDoitems` of course — klcjr89, Jul 16 '14 at 16:15
This should answer it as well as close it...possible duplicate of [Storing custom objects in an NSMutableArray in NSUserDefaults](http://stackoverflow.com/questions/537044/storing-custom-objects-in-an-nsmutablearray-in-nsuserdefaults) — danh, Jul 16 '14 at 16:50
I tried the [self.tableView reloadData]; in viewDidLoad but didnt help. How could I check that there is actually data in NSUserDefaults? — NGA, Jul 16 '14 at 17:01

score 0 · Accepted Answer · answered Jul 16 '14 at 16:55

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];

Saving data with NSUserDetaults and load after phone restart wont work

1 Answers1