Question

I have an NSUInteger defined as a property like so:

@property (nonatomic, assign) NSUInteger wordDisplayed;

I need to have this as a property because I need access to read/write to this variable from other methods and classes.

When trying to change the value of this property within a block, I get the following warning:

Capturing ‘self’ strongly in this block is likely to lead to a retain cycle

“Block will be retained by an object strongly retained by the captured object”

How can I update this variable property within a block?

The block I’m using is in a modified UIActionSheet that I’m using to make the UIActionSheet accept blocks.

https://github.com/zoul/Lambda-Alert

Here is an example of my code:

 sectionHeadersAct = [[LambdaSheet alloc] initWithTitle:@"Book 2 Lesson 1"];
    [sectionHeadersAct addButtonWithTitle:@"D. E. F. & G. Teach New Letters" block:^{ 
        wordDisplayed = 15; //This is where I'm trying to change the value
    }];

[sectionHeadersAct showInView:self.view];

Answer 1

This post deals with this certain issue: https://stackoverflow.com/a/8159567/656036

To summarize it: You should use a weak pointer to self. If you use ARC, you can solve this by writing this before your block:

__weak MyObject *weakSelf = self;

And using weakSelf instead of self in the block itself.

EDIT Try this:

__weak ViewController *weakSelf = self;
sectionHeadersAct = [[LambdaSheet alloc] initWithTitle:@"Book 2 Lesson 1"];
[sectionHeadersAct addButtonWithTitle:@"D. E. F. & G. Teach New Letters" block:^{ 
    weakSelf.wordDisplayed = 15;
}];

[sectionHeadersAct showInView:self.view];