Ios – Custom dealloc and ARC (Objective-C)

automatic-ref-countingdeallociosobjective cxcode

In my little iPad app I have a "switch language" function that uses an observer. Every view controller registers itself with my observer during its viewDidLoad:.

- (void)viewDidLoad
{
    [super viewDidLoad];
    [observer registerObject:self];
}

When the user hits the "change language" button, the new language is stored in my model and the observer is notified and calls an updateUi: selector on its registered objects.

This works very well, except for when I have view controllers in a TabBarController. This is because when the tab bar loads, it fetches the tab icons from its child controllers without initializing the views, so viewDidLoad: isn't called, so those view controllers don't receive language change notifications. Because of this, I moved my registerObject: calls into the init method.

Back when I used viewDidLoad: to register with my observer, I used viewDidUnload: to unregister. Since I'm now registering in init, it makes a lot of sense to unregister in dealloc.

But here is my problem. When I write:

- (void) dealloc
{
    [observer unregisterObject:self];
    [super dealloc];
}

I get this error:

ARC forbids explicit message send of 'dealloc'

Since I need to call [super dealloc] to ensure superclasses clean up properly, but ARC forbids that, I'm now stuck. Is there another way to get informed when my object is dying?

Best Answer

When using ARC, you simply do not call [super dealloc] explicitly - the compiler handles it for you (as described in the Clang LLVM ARC document, chapter 7.1.2):

- (void) dealloc
{
    [observer unregisterObject:self];
    // [super dealloc]; //(provided by the compiler)
}
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