Only first object of NSMutableArray is stored in NSUserDefaults

Question

I am trying to store a queue of UILocalNotification to solve the limit problem. I used this approach and it does archive and unarchive my object but only the first one.

How do I archive all objects from my NSMutableArray?

Code

// init/unarchive queue
if (self.queue == nil)
{
    // try loading stored array
    NSUserDefaults *currentDefaults = [NSUserDefaults standardUserDefaults];
    NSData *dataRepresentingSavedArray = [currentDefaults objectForKey:@"LocalNotificationQueue"];
    if (dataRepresentingSavedArray != nil) {
        NSArray *oldSavedArray = [NSKeyedUnarchiver unarchiveObjectWithData:dataRepresentingSavedArray];
        if (oldSavedArray != nil) {
            self.queue = [[NSMutableArray alloc] initWithArray:oldSavedArray];
        }
        else
        {
            self.queue = [[NSMutableArray alloc] init];
        }
    }
    else
    {
        self.queue = [[NSMutableArray alloc] init];
    }
}
// add
[self.queue addObject:notif];

// store queue
[[NSUserDefaults standardUserDefaults] setObject:[NSKeyedArchiver archivedDataWithRootObject:self.queue] forKey:@"LocalNotificationQueue"];

If I add items 1,2,3. Restart and load. I have only 3.

Add 1,2,3. Restart and load. I have 3, 1, 2.

If it matters. This is a Phonegap/Cordova CDVPlugin.

did you remember to synchronize? because it doesn't appear in the code you shared.. — David Ben Ari, Feb 06 '13 at 14:13
You mention `@synchronize(self)` in a comment: Is your code called from multiple threads concurrently? — Martin R, Feb 06 '13 at 14:38
@MartinR It is a Phonegap plugin and called from JavaScript. Maybe there is more than one thread. Not sure... — PiTheNumber, Feb 06 '13 at 14:41

score 1 · Accepted Answer · edited Feb 06 '13 at 15:05

1

After

[[NSUserDefaults standardUserDefaults] setObject:[NSKeyedArchiver archivedDataWithRootObject:self.queue] forKey:@"LocalNotificationQueue"];

You need to call

[[NSUserDefaults standardUserDefaults] synchronize]

To save the user defaults.

edited Feb 06 '13 at 15:05

PiTheNumber

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answered Feb 06 '13 at 14:41

Kasper Welner

545
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After I added `@synchronized(self)` around the whole function and called `synchronise` it works as wanted. Thank you and everybody! – PiTheNumber Feb 06 '13 at 14:57
@synchronized (self) {} makes the code inside the brackets thread-safe. Calling "synchronize" on NSUserDefaults is just saving. They might as well have called the function "save" instead of "synchronize". So the two has nothing to do with each other. – Kasper Welner Feb 06 '13 at 15:36

Oscar Gomez · Answer 2 · 2013-02-06T14:18:43.387

0

Try this, without the NSKeyedArchiver:

[[NSUserDefaults standardUserDefaults] setObject: self.queue] forKey:@"LocalNotificationQueue"];

edited Feb 06 '13 at 14:18

answered Feb 06 '13 at 14:12

Oscar Gomez

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1

I might be blind but... how would this help? – Daij-Djan Feb 06 '13 at 14:24
NSUserDefaults can only store NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary, but not an array of UILocalNotification. – Martin R Feb 06 '13 at 14:30
This does not work. But it looks like `@synchronize(self)` does help. While he still loses one of two added items sometimes... – PiTheNumber Feb 06 '13 at 14:30
@Daij-Djan I think the way the NSKeyedArchiver is archiving the NSArray may have something to do with the issue. – Oscar Gomez Feb 06 '13 at 14:31
@MartinR is right, NSUserDefaults can only store those types of data, I would suggest trying an array of perhaps a JSON NSString or something you can use to recreate your UILocalNotification after reading back from it. – Oscar Gomez Feb 06 '13 at 14:33
1

@OscarGomez thats what the archiver was for! it makes data, no? – Daij-Djan Feb 06 '13 at 14:43

Only first object of NSMutableArray is stored in NSUserDefaults

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