Question

When I update from iOS 4+ to iOS 5, I lose all data in my own app. I also upgraded to OSX Lion and Xcode 4. I back up my iPhone in iTunes and was able to get the data using iPhone Backup Extractor.

I save my app data to a file in the following way:

- (NSString *)iouArrayPath
{
    // Standard way of getting file path for iOS
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *dir = [paths objectAtIndex:0];
    NSLog(@"Directory: %@", dir);

    return pathInDocumentDirectory(@"IouTableArray.data");
}

- (void)archieveIou
{
    NSLog(@"archieveIou");

    // Get the path to the document directory
    NSString *iouPath = [self iouArrayPath];

    // grab the objects to archieve
    NSMutableArray *iouTableArray = [iouViewController iouTableArray];

    // ARCHIVE DATA
    NSMutableData *data = [NSMutableData data];
    NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
    [archiver encodeObject:iouTableArray forKey:@"IouTableArray"];
    [archiver finishEncoding];
    [data writeToFile:iouPath atomically:YES];

    if([data writeToFile:iouPath atomically:YES]) {
        NSLog(@"writeToFile success!");
    }
    else {
        NSLog(@"writeToFile failed");
    }
    [archiver release];
}

This is what I’ve tried to understand. I open the project in Xcode 4, I copy the .data file from the backup and paste it to the /iPhone Simulator/5.0/Applications/Some digit/Documents. Theorectically, when the app starts, it will look into that folder and load the .data file if it exists. It does not. However, the app will work fine if I create some test data and save it. It will replace the backup file with the same file name and properly load it when I restart the app.

This makes me wonder if there is some NSCoder/archieving change between XCode3/XCode4 or between iOS4 and iOS5.

Does anyone know what is going on? Once I figure this out, I plan to use the backup data file and copy it to the current app /Document folder. Actually, come to think of it, I am not sure how to do that either. The /Document folder for the app reside within the phone. I’ll have to see if I can use iTunes and inject the app with the data. Anyways, first things first! Understand the system.

Thanks!

Answer 1

It turns out that iOS5 installs an older version of the app. Strange but make sure you get all your provisioning squared out.