Objective-C Helper Methods

Question

I'm good with Swift but new to objective-C. When user taps button on alert view, that button needs to be disabled for next 24 hours.Code shown below is a helper method that stores key:userId, value:timestamp in NSUserDefaults-which I've never really used. I have some concerns.

My helper method is in a class that only has class methods, so even though I'd like for my helper method to be private, it can't since its called inside class method. Puzzled about how to conceal this from other objects.
Better procedure for logic? The nested if statements look ugly and would probably be hard to read if it wasn't fresh in my mind.
Is it best practice to just copy alertAction input or use inout, since I'm just enabling or disabling button based off logic.
better name for method? Its purpose is to enable/disable alert controller based off logic, and to store in NSUserDefaults. configXXX seems very generic.

Thanks in advance.

    + (UIAlertAction *)configureAlertAction:(UIAlertAction *)alertAction
                                    forUser:(id<BaseUser>)user {
        /// Check User defaults to see if current user has reported this user already.
        /// if not: store userID and timestamp 24 hours out in defaults and enable alert action.
        /// If so, disable action.

        NSUserDefaults *standardDefaults = [NSUserDefaults standardUserDefaults];
        UIAlertAction *modifiedAlertAction = alertAction;

        double currentDate = [[NSDate date] timeIntervalSince1970];
        double previousDate = [standardDefaults doubleForKey:user.userId];

        if (previousDate) {
            if (previousDate > currentDate) {
                // remove from userdefaults..
                [standardDefaults removeObjectForKey:user.userId];
                // enable alert
                [modifiedAlertAction setEnabled:YES];
            } else if (previousDate > currentDate) {
                [modifiedAlertAction setEnabled:NO];
            }
        } else {
            // store in NSuserdefaults
            [modifiedAlertAction setEnabled:YES];
            double expirationDate = currentDate + 86400;
            [standardDefaults setDouble:expirationDate forKey:user.userId];
        }

        return modifiedAlertAction;
    }

You have 2 if statement for `previousDate > currentDate`. Is anything wrong here? — trungduc, Nov 15 '17 at 06:30
Yeah that is a mistake. Second if statement should check if `previousDate < currentDate` thanks. I guess besides that and the fact that I can't keep my helper method private, theres nothing really wrong about the code. In retrospect this is more of a code review and prob doesn't belong here. — , Nov 15 '17 at 06:41

score 0 · Accepted Answer · answered Nov 15 '17 at 06:55

For your questions

1. There isn't really a "private method" in Objective-C. You can learn more here Best way to define private methods for a class in Objective-C

If you don't like nested if statements, it's my suggestion

+ (UIAlertAction *)configureAlertAction:(UIAlertAction *)alertAction
                                forUser:(id<BaseUser>)user {
  /// Check User defaults to see if current user has reported this user already.
  /// if not: store userID and timestamp 24 hours out in defaults and enable alert action.
  /// If so, disable action.

  NSUserDefaults *standardDefaults = [NSUserDefaults standardUserDefaults];

  double currentDate = [[NSDate date] timeIntervalSince1970];
  double previousDate = [standardDefaults doubleForKey:user.userId];

  if (!previousDate) {
    // store in NSuserdefaults
    [alertAction setEnabled:YES];
    double expirationDate = currentDate + 86400;
    [standardDefaults setDouble:expirationDate forKey:user.userId];

    return alertAction;
  }

  BOOL shouldEnableAlert = previousDate > currentDate;
  if (shouldEnableAlert) {
    // remove from userdefaults..
    [standardDefaults removeObjectForKey:user.userId];
  }
  [alertAction setEnabled:shouldEnableAlert];

  return alertAction;
}

1. I don't think you have to copy alert since I'm just enabling or disabling button based off logic. You don't need another alert.
1. In my opinion, the method name is ok.

Objective-C Helper Methods

1 Answers1