Objective C: Troubles archiving an NSDate - iphone

Question

I'm attempting to save an altered NSDate (8am of the start date) in a database to be retrieved anytime the program is run. I am using object archiving. I thought I had the right code, but I can't seem to get it to save. I receive no errors, just the output I've put into my code. I know the date and time is correct because they are seen as output in NSLog. Here is my code:
__dataArea = [NSMutableData data];
__unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:__dataArea];
__archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:__dataArea];
__iDates = [[BCimportantDates alloc] initWithCoder:[NSKeyedUnarchiver unarchiveObjectWithFile: #"firstDate.arch"]];
if ((__iDates.firstDate == nil)){
NSDate *date = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier: NSGregorianCalendar];
NSDateComponents *components = [gregorian components: NSUIntegerMax fromDate: date];
NSLog(#"the date %#",date);
[components setHour: 3];
[components setMinute: 00];
[components setSecond: 00];
__newDate = [gregorian dateFromComponents: components];
[__iDates setFirstDate: __newDate];
NSLog(#"%#",__iDates.firstDate);
[__iDates encodeWithCoder: __archiver];
[__archiver finishEncoding];
if ([__dataArea writeToFile:#"firstDate.arch" atomically:YES] == NO){
NSLog(#"archiving failed. ");
}
}
And here is the implementation of the encoder and decoder functions within BCimportantDates.m:
- (void) encodeWithCoder:(NSCoder *)encoder{
[encoder encodeObject: __firstDate forKey: kfirstDateKey];
}
- (id) initWithCoder: (NSCoder *) decoder{
if (self = [super init]) {
self.firstDate = [decoder decodeObjectForKey:kfirstDateKey];
}
return self;
}
I've tried using breakpoints where __iDates is encoded, where the archiver finishes, and where I check if it worked. The debugging was not that revealing, but to be honest I'm not sure what to look for when it comes to finding this kind of error. What else can I do to figure out this problem? What might be some possible solutions?

Answer 1

I think the problem here is that you are not specifying a path for writeToFile: to write to.
Try this:
NSString *path = [NSTemporaryDirectory() stringByAppendingPathComponent:#"firstDate.arch"];
if ([__dataArea writeToFile:path atomically:YES] == NO){
NSLog(#"archiving failed. ");
}
Which will write your file to a temporary directory, you can simply set a breakpoint or log the path variable to find out where this location is. NSTemporaryDirectory() is simply for an example though, as this folder is only temporary and can be deleted by the system at any time. Here is a category on NSFileManager which may provide you with a more appropriate path.