block not being called on the other end - ios

Question

i'm new to blocks, I have a class of requests with static methods to call me back on UIViewControllers with some blocks
this is the method implementation :
(putting a breakpoint on the block(something) DOES stop there, like it should)
+(void)requestSuggestedLocationsForText:(NSString*)text withBlock:(void (^)(NSArray*callBackArray))block
{
if ([text isEqualToString:#""] || [text isEqualToString:#" "])
{
block(nil);
return;
}
NSString * key = #"someActualKeyHere";
;
NSString * finalText;
NSArray *tagschemes = [NSArray arrayWithObjects:NSLinguisticTagSchemeLanguage, nil];
NSLinguisticTagger *tagger = [[NSLinguisticTagger alloc] initWithTagSchemes:tagschemes options:0];
[tagger setString:text];
NSString *language = [tagger tagAtIndex:0 scheme:NSLinguisticTagSchemeLanguage tokenRange:NULL sentenceRange:NULL];
if ([language isEqualToString:#"he"])
{
finalText = [text stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
}
else
{
finalText = [text stringByReplacingOccurrencesOfString:#" " withString:#"%20"];
}
NSString *urlString = [NSString stringWithFormat:
#"https://maps.googleapis.com/maps/api/place/autocomplete/json?input=%#&types=geocode&sensor=true&key=%#",finalText,key];
NSURL *url = [NSURL URLWithString:urlString];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
// 2
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
if (!responseObject && ![responseObject respondsToSelector:#selector(dataWithData:)])
{
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"Error Retrieving "
message:#"ERROR"
delegate:nil
cancelButtonTitle:#"Ok"
otherButtonTitles:nil];
[alertView show];
return ;
}
NSData * responseData = [NSData dataWithData:responseObject];
NSString *responseString = [NSString stringWithUTF8String:[responseData bytes]];
NSError *err;
if ([responseString respondsToSelector:#selector(JSONObjectWithData:options:error:)])
{
NSDictionary *json = [NSJSONSerialization JSONObjectWithData:[responseString dataUsingEncoding:NSUTF8StringEncoding] options:kNilOptions error:&err];
NSArray * predictions = [json valueForKey:#"predictions"];
block(predictions);
}
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
// 4
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"Error Retrieving Weather"
message:[error localizedDescription]
delegate:nil
cancelButtonTitle:#"Ok"
otherButtonTitles:nil];
[alertView show];
}];
// 5
[operation start];
}
this is how I call it, notice the NSLog, i put a breakpoint on it and its never called
which is exactly what I want to occur.
[Requests requestSuggestedLocationsForText:text withBlock:^(NSArray *callBackArray)
{
NSLog(#"ROFL");
}];
for the record, I have tried the same method with a different signature (without the returning variable name like so :
+(void)requestSuggestedLocationsForText:(NSString*)text withBlock:(void (^)(NSArray*))block;
still didn't fire my breakpoint :(

Answer 1

I think that this:
if ([responseString respondsToSelector:#selector(JSONObjectWithData:options:error:)])
{
NSDictionary *json = [NSJSONSerialization JSONObjectWithData:[responseString dataUsingEncoding:NSUTF8StringEncoding] options:kNilOptions error:&err];
NSArray * predictions = [json valueForKey:#"predictions"];
block(predictions);
}
Never runs because as far as I know, NSString doesn't declare JSONObjectWithData. Your break point will never hit because it will never be called.
It seems like it could just be:
NSData * responseData = [NSData dataWithData:responseObject];
NSError *err;
NSDictionary *json = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&err];
if (!err) {
NSArray * predictions = [json valueForKey:#"predictions"];
block(predictions);
}
else {
block(nil);
}
The other way you convert it to a string, then back to data, why not just keep it as data?