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delegate not triggering is a mystery in ios

Anonymous User194013-Oct-2014

I have developed this class that is basically a UIAlertView with an input field that runs on blocks. So, whatever the user does on the alertView (click cancel, ok, or fill the text), returns to a block:

HEADER

typedef void (^onClickBlock)(NSInteger buttonIndex, NSString *textoInput);
 
 
@interface AlertViewBlocoComInput : NSObject
 
- (void)mostrarAlertViewBlocoComTitulo:(NSString *)titulo
                              mensagem:(NSString *)mensagem
                     tituloBotaoCancel:(NSString *)tituloCancel
                     outrosBotoesArray:(NSArray *)titulosOutrosBotoes
                   inputComPlaceHolder:(NSString *)textoPlaceholder
                      comBlocoExecucao:(onClickBlock)bloco;
 
@end


IMPLEMENTATION

 

@interface AlertComBloco : UIAlertView
@property (nonatomic, copy) onClickBlock runOnClickBlock;
@end
 
 
@implementation AlertComBloco
@end
 
 
@interface AlertViewBlocoComInput () <UIAlertViewDelegate>
@end
 
 
@implementation AlertViewBlocoComInput 
 
 
- (void)mostrarAlertViewBlocoComTitulo:(NSString *)titulo
                              mensagem:(NSString *)mensagem
                     tituloBotaoCancel:(NSString *)tituloCancel
                     outrosBotoesArray:(NSArray *)titulosOutrosBotoes
                   inputComPlaceHolder:(NSString *)textoPlaceholder
                      comBlocoExecucao:(onClickBlock)bloco
 
{
 
  AlertComBloco *alerta = [[AlertComBloco alloc] initWithTitle:titulo
                                                       message:mensagem
                                                      delegate:self
                                             cancelButtonTitle:tituloCancel
                                             otherButtonTitles:nil];
  alerta.runOnClickBlock =bloco;
 
  // adicionar os outros botões
  for (NSString *umOutroBotao in titulosOutrosBotoes) {
    [alerta addButtonWithTitle:umOutroBotao];
  }
 
 
  [alerta setAlertViewStyle:UIAlertViewStylePlainTextInput];
  UITextField *input = [alerta textFieldAtIndex:0];
  input.placeholder = textoPlaceholder;
 
  [alerta show];
 
}
 
 
 
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
 
  AlertComBloco *alerta = (AlertComBloco *)alertView;
  onClickBlock bloco = alerta.runOnClickBlock;
 
  UITextField *input = [alertView textFieldAtIndex:0];
 
  if (bloco) {
    bloco(buttonIndex, input.text);
  }
 
}
 
 
@end




run it, it shows the alertView with the message, placeholder, perfect. I click cancel or fill the text and press ok and the alertview:clickedButtonAtIndex: is never triggered. I am not seeing why.

iphoneiphone mobile development 
Updated on 13-Oct-2014
Anonymous User

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2 Answers

Anonymous User

Anonymous User

13-Oct-2014
You can directly subclass UIAlertView and add your own initializer. I have abstracted your classes to a single subclass of UIAlertView and it works fine. Please see my posts below,

typedefvoid (^onClickBlock)(NSInteger buttonIndex, NSString *textoInput);
 
        @interface AlertComBloco : UIAlertView<UIAlertViewDelegate>
        @property (nonatomic, copy) onClickBlock runOnClickBlock;
        @end
 
 
        @implementation AlertComBloco 
 
        - (id)initWithTitulo:(NSString *)titulo mensagem:(NSString*)mensagem tituloBotaoCancel:(NSString*)tituloCancel outrosBotoesArray:(NSArray *)titulosOutrosBotoes inputComPlaceHolder:(NSString *)textoPlaceholder
            comBlocoExecucao:(onClickBlock)bloco{
          if(self = [self initWithTitle:titulo message:mensagem delegate:self cancelButtonTitle:tituloCancel otherButtonTitles:nil, nil]){
            _runOnClickBlock = bloco;
            for (NSString *umOutroBotao in titulosOutrosBotoes) {
              [self addButtonWithTitle:umOutroBotao];
            }
            [self setAlertViewStyle:UIAlertViewStylePlainTextInput];
            UITextField *input = [self textFieldAtIndex:0];
            input.placeholder = textoPlaceholder;
 
          }
          return self;
        } 
 
 
        - (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
        {
 
          UITextField *input = [alertView textFieldAtIndex:0];
 
          if (self.runOnClickBlock) {
            self.runOnClickBlock(buttonIndex, input.text);
          }
 
        }
 
        @end

Then, you could call it with the block in your view controller just like this,

   - (void)showAlert:(id)sender{
  AlertComBloco *alertCombo = [[AlertComBloco alloc] initWithTitulo:@"Hi" mensagem:@"Custom Alert" tituloBotaoCancel:@"Cancel" outrosBotoesArray:@[@"Other"] inputComPlaceHolder:@"Placeholder" comBlocoExecucao:^(NSInteger buttonIndex, NSString *textoInput) {
    NSLog(@"Button at index %ld, with text %@", (long)buttonIndex, textoInput);
  }];
  [alertCombo show];
}

Anonymous User

Anonymous User

13-Oct-2014
You haven't shown us how you're calling this but most likely your AlertViewBlocoComInput is a local variable that has fallen out of scope and is therefore deallocated before the user completes their input. You can demonstrate this by temporarily adding a dealloc method that will tell you when the object is deallocated.

- (void)dealloc

            {

                NSLog(@"%s", __PRETTY_FUNCTION__);

            }

In terms of fixing this, you could make your AlertViewBlocoComInput instance a class property, so it won't be released until you manually nil it. Or you can make AlertViewBlocoComInput maintain a strong reference to itself until clickedButtonAtIndex is called.

Or, easiest, leverage the fact that UIAlertView already retains itself, so you can retire AlertComBloco altogether, folding it into AlertViewBlocoComInput:

typedef void (^onClickBlock)(NSInteger buttonIndex, NSString *textoInput);

 

        @interface AlertViewBlocoComInput : UIAlertView <UIAlertViewDelegate>

 

        - (instancetype)initComTitulo:(NSString *)titulo

                             mensagem:(NSString *)mensagem

                    tituloBotaoCancel:(NSString *)tituloCancel

                    outrosBotoesArray:(NSArray *)titulosOutrosBotoes

                  inputComPlaceHolder:(NSString *)textoPlaceholder

                     comBlocoExecucao:(onClickBlock)bloco;

 

        @property (nonatomic, copy) onClickBlock runOnClickBlock;

 

        @end

 

        @implementation AlertViewBlocoComInput

 

        - (instancetype)initComTitulo:(NSString *)titulo

                             mensagem:(NSString *)mensagem

                    tituloBotaoCancel:(NSString *)tituloCancel

                    outrosBotoesArray:(NSArray *)titulosOutrosBotoes

                  inputComPlaceHolder:(NSString *)textoPlaceholder

                     comBlocoExecucao:(onClickBlock)bloco

 

        {

            self = [super initWithTitle:titulo message:mensagem delegate:self cancelButtonTitle:tituloCancel otherButtonTitles:nil];

 

            if (self) {

                self.runOnClickBlock =bloco;

 

                // adicionar os outros botões

                for (NSString *umOutroBotao in titulosOutrosBotoes) {

                    [self addButtonWithTitle:umOutroBotao];

                }

 

                [self setAlertViewStyle:UIAlertViewStylePlainTextInput];

                UITextField *input = [self textFieldAtIndex:0];

                input.placeholder = textoPlaceholder;

            }

 

            return self;

        }

 

        - (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex

        {

            if (self.runOnClickBlock) {

                UITextField *input = [alertView textFieldAtIndex:0];

                self.runOnClickBlock(buttonIndex, input.text);

            }

        }

 

        @end

And you'd call it like so:

AlertViewBlocoComInput *obj = [[AlertViewBlocoComInput alloc] initComTitulo:@"title" mensagem:@"message" tituloBotaoCancel:@"OK" outrosBotoesArray:nil inputComPlaceHolder:@"Placeholder" comBlocoExecucao:^(NSInteger buttonIndex, NSString *textoInput) {

    // do whatever you want with `buttonIndex` and `textoInput` here

    //

    // NSLog(@"%ld %@", (long)buttonIndex, textoInput);

}];

[obj show];

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