Inspection to detect a strong reference in a block

Permanently deleted user

Created July 11, 2012 20:00

We've got some code that uses blocks, however, the implementor didn't ensure that references to self in the block were weak, thus causing a retain cycle.

Is it possible to flag code such as:

if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])

{

[actionSheet addButtonWithTitle:@"Take a Photo" usingBlock:^

{

[self showProfilePicture:self.server.profile from:MCTakePictureSourceTypeCamera];

}];

}

with at least a warning that this code could/will cause a retain cycle. The appropriate implementation for this, pre-arc, is this:

__block MCProfileWireframe* blockSelf = self;

if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
{
     [actionSheet addButtonWithTitle:@"Take a Photo" usingBlock:^
     {
          [blockSelf showProfilePicture:blockSelf.server.profile from:MCTakePictureSourceTypeCamera];
     }];
}

Thanks.

2 comments

Anton Makeev

Created July 12, 2012 08:42

Seamus, we'll add such an inspection in future, here is a request for you to watch and vote: http://youtrack.jetbrains.com/issue/OC-4088

Permanently deleted user

Created July 12, 2012 14:26

Thanks!

Good stuff.

I do want to let your team know that the ability to submit bugs and feature requests, and track them, is a huge plus for me. I list it as a feature when trying to convince folks to try AppCode.

Please sign in to leave a comment.