Why is this delegate not triggering is a mystery - ios

Question

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
I 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.
thanks

Answer 1

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,
typedef void (^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];
}

Answer 2

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];