Lanzar búsqueda mientras escribes

gistfile1.m

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    NSString *newSearch = [textField.text stringByReplacingCharactersInRange:range withString:string];
    NSLog(@"%@",newSearch);
    
    if ([newSearch length] >= MIN_NUMBER_OF_CHARACTERS_TO_LAUCH_SEARCH)
    {
        //Hacer búsqueda con newSearch
    }
    
    return YES;
}