Error archiving two arrays in objective-c - iphone

Question

I'm going through the Beginning iOS 5 example and trying to tweak it for my usage. I have a DataManager singleton object that has properties of:
#property (nonatomic, strong) NSArray *frequencyArray;
#property (nonatomic, strong) NSMutableArray *networkArray;
As I'm using ARC, my singleton looks like:
- (id)init {
if (self = [super init]) {
_networkArray = [[NSMutableArray alloc] init];
}
return self;
}
+ (id)sharedInstance {
if (sharedDmgr == nil) {
sharedDmgr = [[super allocWithZone:NULL] init];
}
return sharedDmgr;
}
+ (id)allocWithZone:(NSZone *)zone {
return [self sharedInstance];
}
- (id)copyWithZone:(NSZone *)zone {
return self;
}
I followed the example code to conform this class to NSCoding and NSCopying. I created two methods in this class to archive itself, and unarchive itself. Those are:
- (NSString *)dataFilePath {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
return [documentsDirectory stringByAppendingFormat:ARCHIVE_FILE_NAME];
}
- (void)archiveAppData {
NSMutableData *data = [[NSMutableData alloc] init];
NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
[archiver encodeObject:self forKey:ARCHIVE_DATA];
// [archiver encodeObject:_frequencyArray forKey:DMGR_FREQUENCY_ARRAY];
// [archiver encodeObject:_networkArray forKey:DMGR_NETWORK_ARRAY];
[archiver finishEncoding];
// BOOL success = [data writeToFile:[self dataFilePath] atomically:YES];
NSError *error;
BOOL success = [data writeToFile:[self dataFilePath] options:NSDataWritingAtomic error:&error];
if (!success) {
NSLog(#"Could not write file %#", [error description]);
}
}
- (void)unarchiveAppData {
NSData *data = [[NSMutableData alloc] initWithContentsOfFile:[self dataFilePath]];
NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
sharedDmgr = [unarchiver decodeObjectForKey:ARCHIVE_DATA];
// self.frequencyArray = [unarchiver decodeObjectForKey:DMGR_FREQUENCY_ARRAY];
// self.networkArray = [unarchiver decodeObjectForKey:DMGR_NETWORK_ARRAY];
[unarchiver finishDecoding];
}
I get the error:
Could not write file Error Domain=NSCocoaErrorDomain Code=513 "The
operation couldn’t be completed. (Cocoa error 513.) "The operation
couldn’t be completed. Operation not permitted"}
which I googled and saw that it's referring to modifying the bundle. But I don't see where I'm doing that since I thought I was writing to the documents directoroy with my [self dataFilePath] code.
When my application resigns active, I call the archiveAppData method. When my first viewController loads, I call the unarchiveAppData. As you can see from my commented out code, I tried to just encode those two arrays instead, and then decode those as opposed to the DataManager object itself, but that didn't seem to work either. Any thoughts on what I'm doing wrong? Thanks.