Question

I have the following code, which is causing a leak, despite ARC being enabled on that file:

TWTweetComposeViewController *tweetViewController = [[TWTweetComposeViewController alloc] init];

[tweetViewController setInitialText:[self facebookAndTwitterStatus]];

tweetViewController.completionHandler = ^(TWTweetComposeViewControllerResult result) {
    if(result == TWTweetComposeViewControllerResultDone) {
        // the user finished composing a tweet
    } else if(result == TWTweetComposeViewControllerResultCancelled) {
        // the user cancelled composing a tweet
    }
    [self dismissViewControllerAnimated:YES completion:nil];
};

[self presentViewController:tweetViewController animated:YES completion:nil];

[self hideSettingsPopover];

Obviously i don’t have a release, but how can i get rid of this leak?

Answer 1

Use __block on your TwTweetViewController variable tweetViewController
and set tweetViewController to nil in your completion handler.

**__block** TweetComposeViewController *tweetViewController = [[TWTweetComposeViewController alloc] init];

[tweetViewController setInitialText:[self facebookAndTwitterStatus]];

tweetViewController.completionHandler = ^(TWTweetComposeViewControllerResult result) {
    if(result == TWTweetComposeViewControllerResultDone) {
        // the user finished composing a tweet
    } else if(result == TWTweetComposeViewControllerResultCancelled) {
        // the user cancelled composing a tweet
    }
    [self dismissViewControllerAnimated:YES completion:nil];
    **tweetViewController = nil;**
};

The __block copies your tweetViewController and it’s released when you set it to nil.
This is explained in Transitioning to ARC release notes.
http://developer.apple.com/library/ios/#releasenotes/ObjectiveC/RN-TransitioningToARC/_index.html

Not sure why your question was down voted.