How to properly subclassing a UIActionSheet

Question

I want subclass a UIActionSheet to use a block approach instead of delegate. My problem is when I call the super initialization on UIActionSheet the variadic ... at the end of the method aren't recognized as a va_list and the action sheet only show the first button.

Here class implementation .m

@interface FLActionSheet ()
@property (nonatomic,strong) actionClickedBlock clickedBlock;
@end

@implementation FLActionSheet

+ (id)actionSheetWithTitle:(NSString *)title
              clickedBlock:(actionClickedBlock)clickedBlock
         cancelButtonTitle:(NSString *)cancelButtonTitle
    destructiveButtonTitle:(NSString *)destructiveButtonTitle
         otherButtonTitles:(NSString *)otherButtonTitles, ...
{
    return [[self alloc] initWithTitle:title
                          clickedBlock:clickedBlock
                     cancelButtonTitle:cancelButtonTitle
                destructiveButtonTitle:destructiveButtonTitle
                     otherButtonTitles:otherButtonTitles];
}

- (id)initWithTitle:(NSString *)title
       clickedBlock:(actionClickedBlock)clickedBlock
  cancelButtonTitle:(NSString *)cancelButtonTitle
destructiveButtonTitle:(NSString *)destructiveButtonTitle
  otherButtonTitles:(NSString *)otherButtonTitles, ...
{
    self = [super initWithTitle:title
                       delegate:self
              cancelButtonTitle:cancelButtonTitle
         destructiveButtonTitle:destructiveButtonTitle
              otherButtonTitles:otherButtonTitles,nil];

    if (self)
    {
        self.clickedBlock = [clickedBlock copy];
    }
    return self;
}

- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
{
    self.clickedBlock(buttonIndex);
}

@end

And here how I initialize the action sheet:

[[[FLActionSheet alloc] initWithTitle:@"Ordina per..."
                            clickedBlock:^(NSInteger buttonIndex) {

                                switch (buttonIndex)
                                {
                                    case 0:

                                        break;

                                    default:
                                        break;
                                }
                            }
                       cancelButtonTitle:nil
                  destructiveButtonTitle:@"Annulla"
                       otherButtonTitles:@"Data crescente", @"Data decrescente", @"Mittente crescente", @"Mittente decrescente"]
     showFromBarButtonItem:myBarButtonItem
     animated:YES];

And here the result:

I'm definitely doing something wrong but I do not understand what. Ideas ?

Answer 1

1. UIActionSheet is not designed to be subclassed.

2. There are other ways how to use it with blocks. Best is to create a category, that implements delegate protocol and store the block using associated ojects mechanism. Implementation here.

3. I think initWithTitle:delegate:cancelButtonTitle:... is not the designated initializer and it is implemented using [self init] with following setTitle: and addButtonWithTitle: calls. You should do it similarily.

4. In fact, with variadic method, you have no other option. To collect all arguments, you have to use va_list and related functions. Implementation here. Then on each of them you call addButtonWithTitle: as I mentioned.