Question

I have several UIAlertViews that i want to display in a sequential order, and only move on to display the next UIAlertView once the previous one has been dismissed (by user clicking okay).

I know about the didDismissWithButtonIndex delegate and adding a tag, but this doesn’t really help too much as there could be upto 3 UIAlertViews invoked and not necessarily in the same order everytime. see code:

if(condition 1){
    alert1 = // UIAlertView[[.....
    [alert1 show]
}

if(condition 2){
    alert2 = // UIAlertView[[.....
    [alert2 show]
}

if(condition 3){
    alert3 = // UIAlertView[[.....
    [alert3 show]
}

The above will just add 3 Alerts on top of each other (depending on how many conditions are met) which is not what I want. I want to be able to only show one at a time and then the next one (if there is one) after the user hits the ok button.

I had the idea of maybe adding the messages to a queue and then processing that queue removing the alert every time an alert is dismissed but i’m not sure how id go about doing that.

Any ideas would be much appreciated.
Thanks

Answer 1

You could easily do it in the UIAlertView delegate method, called once an alert view is dismissed. So, UIAlertViewDelegate defines the following delegate method:

– alertView:didDismissWithButtonIndex:

Implement that method, and make sure your class is the delegate of the UIAlertViews you create. This method is the perfect place to then show the next alert based on the one being dismissed by the user.

If your requirement is “Display up to three alerts, sequentially, but not always in the same order” i’d probably put the alerts in to an array, and then in the delegate method get the next alert out of the array to show. It doesn’t have to be any more complex than that really; the key thing is that the delegate method implementation is the best place to show the next alert.

Pseudo Code Example:

Define an array; NSMutableArray * alerts_;

- (void)showAlertSequence {
    if ( !alerts_ ) {
        alerts_ = [[NSMutableArray alloc] init];
    }

    [alerts_ addObjects;<My alerts>];

    [self showSequencedAlertFrom:nil];
}

- (BOOL)showSequencedAlertFrom:(UIAlertView *)sourceAlertView {

    if ( !sourceAlertView ) {
        [[alerts_ objectAtIndex:0] show];
    }
    else {
        NSInteger index = [alerts_ indexOfObject:sourceAlertView];

        if ( index < [alerts_ count] ) {
            [[alerts_ objectAtIndex:index++] show];
        }
    }

    return NO;
}

– alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)index {

    // Show the next alert or clean up if we're at the end of the sequence.
    if ( ![self showSequencedAlertFrom:alertView] ) {
        [alerts_ removeAllObjects];
    }
}   

As an aside; three sequential alerts will really annoy you users 😉