What is the best way to deal with the NSDateFormatter locale “feechur”?

Question

It seems that NSDateFormatter has a \"feature\" that bites you unexpectedly: If you do a simple \"fixed\" format operation such as:

NSDateForma         


        

Answer 1

Instead of subclassing, you could create an NSDateFormatter category with an additional initializer that takes care of assigning the locale and possibly also a format string, so you'd have a ready-to-use formatter right after initializing it.

@interface NSDateFormatter (LocaleAdditions)

- (id)initWithPOSIXLocaleAndFormat:(NSString *)formatString;

@end

@implementation NSDateFormatter (LocaleAdditions)

- (id)initWithPOSIXLocaleAndFormat:(NSString *)formatString {
    self = [super init];
    if (self) {
        NSLocale *locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"];
        [self setLocale:locale];
        [locale release];
        [self setFormat:formatString];
    }
    return self;
}

@end

Then you could use NSDateFormatter anywhere in your code with just:

NSDateFormatter* fmt = [[NSDateFormatter alloc] initWithPOSIXLocaleAndFormat:@"yyyyMMddHHmmss"];

You might want to prefix your category method somehow to avoid name conflicts, just in case Apple decides to add such a method in a future version of the OS.

In case you're always using the same date format(s), you could also add category methods that return singleton instances with certain configurations (something like +sharedRFC3339DateFormatter). Be aware however that NSDateFormatter is not thread-safe and you have to use locks or @synchronized blocks when you're using the same instance from multiple threads.