How do I correctly use ABAddressBookCreateWithOptions method in iOS 6?

Now that the NDA has been lifted, here is my solution for this for the where you need replace a method which returns an Array. (If you'd rather not block while the user is deciding and are ready to potentially rewrite some of your existing code, please look at David's solution below):

ABAddressBookRef addressBook = ABAddressBookCreate();__block BOOL accessGranted = NO;if (ABAddressBookRequestAccessWithCompletion != NULL) { // we're on iOS 6    dispatch_semaphore_t sema = dispatch_semaphore_create(0);    ABAddressBookRequestAccessWithCompletion(addressBook, ^(bool granted, CFErrorRef error) {        accessGranted = granted;        dispatch_semaphore_signal(sema);    });    dispatch_semaphore_wait(sema, DISPATCH_TIME_FOREVER);    dispatch_release(sema);    }else { // we're on iOS 5 or older    accessGranted = YES;}if (accessGranted) {    NSArray *thePeople = (__bridge_transfer NSArray*)ABAddressBookCopyArrayOfAllPeople(addressBook);    // Do whatever you need with thePeople...}

Hope this helps somebody...

Most answers I've seen to this question do crazy complicated things with GCD and end up blocking the main thread. It's not necessary!

Here's the solution I've been using (works on iOS 5 and iOS 6):

- (void)fetchContacts:(void (^)(NSArray *contacts))success failure:(void (^)(NSError *error))failure {  if (ABAddressBookRequestAccessWithCompletion) {    // on iOS 6    CFErrorRef err;    ABAddressBookRef addressBook = ABAddressBookCreateWithOptions(NULL, &err);    if (err) {      // handle error      CFRelease(err);      return;    }    ABAddressBookRequestAccessWithCompletion(addressBook, ^(bool granted, CFErrorRef error) {      // ABAddressBook doesn't gaurantee execution of this block on main thread, but we want our callbacks to be      dispatch_async(dispatch_get_main_queue(), ^{        if (!granted) {          failure((__bridge NSError *)error);        } else {          readAddressBookContacts(addressBook, success);        }        CFRelease(addressBook);      });    });  } else {    // on iOS < 6    ABAddressBookRef addressBook = ABAddressBookCreate();    readAddressBookContacts(addressBook, success);    CFRelease(addressBook);  }}static void readAddressBookContacts(ABAddressBookRef addressBook, void (^completion)(NSArray *contacts)) {  // do stuff with addressBook  NSArray *contacts = @[];  completion(contacts);}

The other high ranking answer has problems:

• it unconditionally calls API that don't exist in iOS older than 6, so your program will crash on old devices.
• it blocks the main thread, so your app is unresponsive, and not making progress, during the time the system alert s up.

Here's my MRC take on it:

        ABAddressBookRef ab = NULL;        // ABAddressBookCreateWithOptions is iOS 6 and up.        if (&ABAddressBookCreateWithOptions) {          NSError *error = nil;          ab = ABAddressBookCreateWithOptions(NULL, (CFErrorRef *)&error);    #if DEBUG          if (error) { NSLog(@"%@", error); }    #endif          if (error) { CFRelease((CFErrorRef *) error); error = nil; }        }        if (ab == NULL) {          ab = ABAddressBookCreate();        }        if (ab) {          // ABAddressBookRequestAccessWithCompletion is iOS 6 and up.          if (&ABAddressBookRequestAccessWithCompletion) {            ABAddressBookRequestAccessWithCompletion(ab,               ^(bool granted, CFErrorRef error) {                 if (granted) {                   // constructInThread: will CFRelease ab.                   [NSThread detachNewThreadSelector:@selector(constructInThread:)                                            toTarget:self                                          withObject:ab];                 } else {                   CFRelease(ab);                   // Ignore the error                 }                 // CFErrorRef should be owned by caller, so don't Release it.               });          } else {            // constructInThread: will CFRelease ab.            [NSThread detachNewThreadSelector:@selector(constructInThread:)                                     toTarget:self                                   withObject:ab];          }        }      }