Detect file creation date on iPhone OS?

Question

I was planning on writing some code whose logic was based upon testing the creation date of a particular file in my app's Documents folder. Turns out, when I call -[NSFileManager attributesOfItemAtPath:error:], NSFileCreationDate isn't one of the provided attributes.

Is there no way to discover a file's creation date?

Thanks.

Answer 1

The fileCreationDate is indeed part of the dictionary. Here's a method that gets passed a file URI and grabs some of the attributes from the file:

- (NSDictionary *) attributesForFile:(NSURL *)anURI {

// note: singleton is not thread-safe
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *aPath = [anURI path];

if (![fileManager fileExistsAtPath:aPath]) return nil;

NSError *attributesRetrievalError = nil;
NSDictionary *attributes = [fileManager attributesOfItemAtPath:aPath
                           error:&attributesRetrievalError];

if (!attributes) {
   NSLog(@"Error for file at %@: %@", aPath, attributesRetrievalError);
   return nil;
}

NSMutableDictionary *returnedDictionary = 
   [NSMutableDictionary dictionaryWithObjectsAndKeys:
        [attributes fileType], @"fileType",
        [attributes fileModificationDate], @"fileModificationDate",
        [attributes fileCreationDate], @"fileCreationDate",
        [NSNumber numberWithUnsignedLongLong:[attributes fileSize]], @"fileSize",
    nil];

return returnedDictionary;
}

Answer 2

According to Apple's reference, NSFileCreationDate is available in 2.0+:

NSFileCreationDate The key in a file attribute dictionary whose value indicates the file's creation date.

The corresponding value is an NSDate object.

Available in iPhone OS 2.0 and later.

Declared in NSFileManager.h.