iphone UIAlertView Modal

Question

Is it possible to present a UIAlertView and not continue executing the rest of the code in that method until the user responds to the alert?

Thanks in advance.

Answer 1

If the code that needs to wait is all in the same method (or can be), blocks can be another option. I've created a UIAlertView subclass to handle this. Just keep in mind that execution will still continue past the [alert show] call; this just gives you a way to pass along your stack variables without making new in-between class variables. Also, if you aren't already familiar with Objective-C blocks, you should read the documentation on it; there are a few gotchas and some odd syntax you should be aware of.

Goes something like this:

typedef void (^MyAlertResult)(NSInteger clickedButtonIndex);

@interface MyBlockAlert : UIAlertView
{
    MyAlertResult finishedBlock;
}
- (void) showWithCompletionBlock:(MyAlertResult)block;
...

- (void) showWithCompletionBlock:(MyAlertResult)block
{
    self.delegate = self;
    finishedBlock = [block copy];
    [self show];
}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
    finishedBlock(buttonIndex);
    [finishedBlock release];
    finishedBlock = nil;
}

used like this:

__block NSArray* arrayOfDeletes; // set to something
MyBlockAlert* areYouSureAlert = [[MyBlockAlert alloc] initWithTitle:@"Really delete?" message:@"Message" delegate:nil cancelButtonTitle:@"Cancel" otherButtonTitles:@"Delete", nil];

[arrayOfDeletes retain]; // Make sure retain count is +1

[areYouSureAlert showWithCompletionBlock:
^(NSInteger clickedButtonIndex)
{
    if (clickedButtonIndex == 1)
    {
        // Clicked okay, perform delete
    }
    [arrayOfDeletes release];
}];
[areYouSureAlert release];

This was a quick implementation, so feel free to find any bugs; but you get the idea.