ios - Do we need to use __weak self inside UIAnimationBlocks in ARC?

Question

Do we need to use __weak self inside UIAnimation Blocks as given below? Whether it will create retain cycle issue if we are not specifying self as weak?

[UIView animateWithDuration:animationDuration 
                      delay:0 
                    options:UIViewAnimationCurveEaseInOut 
                 animations:^{
        [self doSomething];
    } completion:^(BOOL finished) {
        if (finished) {
            [self doSomething];
        }
    }];

I am also confused in the following scenario. Any thoughts on this? please share your comments.

[self.navController dismissViewControllerAnimated:animated 
                                       completion:^{
                                                      [self doSomething];
                                                  }];

Should we use weak self here?

Answer 1

This is not a retain cycle. A retain cycle would be

self -> block -> self

In this case we have

animation framework -> block
block -> self

where the first retain is only temporary - the block gets released when the animation ends. Even if a retain cycle happens, it will be only temporary and it won't prevent object deallocation.