Question

Cannot retrieve member objects in TTPostController:postController method

I’ve been struggling to figure out why I’m unable to return any of my member objects when using TTPostController:postController method to send HTTP request. Here’s the code I’m using.

Header:

@interface NewReplyViewController : TTPostController <TTPostControllerDelegate> {
    NSString * _thread_id;
}

@property (nonatomic, assign) NSString * thread_id;

-(id)initWithThreadId:(NSString *)threadId;

@end

Implementation:

@synthesize thread_id = _thread_id;

-(id)initWithThreadId:(NSString *)threadId {
    self = [super initWithNibName:nil bundle:nil];

    if (self) {
        self.delegate  = self;
        self.thread_id = threadId;
        self.title     = kPostReplyPhrase;

        self.navigationItem.rightBarButtonItem.title = kPostPhrase;
    }

    return self;
}

- (void)postController:(TTPostController *)postController 
           didPostText:(NSString *)text 
            withResult:(id)result {

    NSLog(@"postController:postController self.threadid = %@", self.thread_id);
}

Once I reach the NSLog part, where it tries to return the objects thread id after pressing the send button, the app crashes without much detail. The stack trace shows my _thread_id object, but I can’t figure out why I’m not able to get to it. Any ideas on what I could be doing wrong?

Here are some details about the crash and the stack trace:
https://i.stack.imgur.com/NL2tD.png

Thread 1, Queue : com.apple.main-thread
    #0  0x01058657 in ___forwarding___ ()
#1  0x01058522 in __forwarding_prep_0___ ()
#2  0x00a99fcb in _NSDescriptionWithLocaleFunc ()
#3  0x010d0c1d in __CFStringAppendFormatCore ()
#4  0x01018507 in _CFStringCreateWithFormatAndArgumentsAux ()
#5  0x010a01ee in _CFLogvEx ()
#6  0x00b179a4 in NSLogv ()
#7  0x00b17913 in NSLog ()
#8  0x0000a7a0 in -[NewReplyViewController postController:didPostText:withResult:] at /Users/Ken/iOS/Forums/NewReplyViewController.m:59
#9  0x00048b8f in -[TTPostController dismissAnimationDidStop] ()
#10 0x00369fb9 in -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] ()
#11 0x00369e4b in -[UIViewAnimationState animationDidStop:finished:] ()
#12 0x0027999b in run_animation_callbacks(double, void*) ()
#13 0x0021e651 in CA::timer_callback(__CFRunLoopTimer*, void*) ()
#14 0x010c88c3 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ ()
#15 0x010c9e74 in __CFRunLoopDoTimer ()
#16 0x010262c9 in __CFRunLoopRun ()
#17 0x01025840 in CFRunLoopRunSpecific ()
#18 0x01025761 in CFRunLoopRunInMode ()
#19 0x01c2e1c4 in GSEventRunModal ()
#20 0x01c2e289 in GSEventRun ()
#21 0x00347c93 in UIApplicationMain ()
#22 0x00001fa9 in main ()

Answer 1

For NSString @property, always use copy:

@property (nonatomic, copy) NSString * thread_id;

AFAIK there are only two situations where you can use @property(assign):

• For literal types (i.e. non-object), for example: int, float, NSUInteger, CGPoint etc
• When you only want to have weak-reference to an object that will outlive the class object, the most common examples are delegate and view controller: @property (nonatomic, assign) UIViewController *viewController

p/s: Weak reference prevents cyclic dependency, for example: controller retains view, then view retains controller so in the end both cannot be released