Multiple UIAlertControllers in iOS

Question

In my app there are scenarios where multiple alerts could come. But as in iOS8 UIAlertview turned to UIAlertController, i am not able to show multiple alerts as you can not present two or more controllers at the same time.

How can I achieve this using UIAlertController?

Answer 1

You need to present it on a top presented controller, you can use this extension:

extension UIViewController {

    var topController: UIViewController {
        presentedViewController?.topController ?? self
    }
}

self.topController.present(alert, animated: true)

Answer 2

You can keep track of a list of alerts to show in your view controller as an instance variable, say

NSMutableArray *alertsToShow;

You can present the first UIAlertController, and add a UIAlertAction in which you present the next alert (if applicable), with a recursive-like method:

- (void)showAlertIfNecessary {
    if (alertsToShow.count == 0)
        return;

    NSString *alert = alertsToShow[0];
    [alertsToShow removeObjectAtIndex:0];

    UIAlertController *alertController = [UIAlertController
                          alertControllerWithTitle:@"Title"
                          message:alert
                          preferredStyle:UIAlertControllerStyleAlert];
    UIAlertAction *okAction = [UIAlertAction 
        actionWithTitle:@"OK"
                  style:UIAlertActionStyleDefault
                handler:^(UIAlertAction *action)
                {
                    [self showAlertIfNecessary];
                }];
    [alertController addAction:okAction];
    [self presentViewController:alertController animated:YES completion:nil];
}

Note that this can get very annoying to the user, if he/she needs to click through a lot of messages. You might consider combining them into a single message.