A UIKit ViewController keeps an upload completion block in a property, and the block changes one of the ViewController's labels. After the upload finishes the closure is still sitting in that property. How would you break the loop between it and self?
The surest way is to assign nil to the property right after the closure runs, removing the arrow from ViewController to closure; and to cover paths where it never runs (failure, leaving the screen), capture [weak self] in the closure so the reverse arrow is weak too, blocking it twice over.
Memory and ARCShort answerBasics
Give me a concrete code example that creates a retain cycle, and fix it.
#closure #retain-cycle #lifetime
Memory and ARCMultiple choiceBasics
Which of these two snippets creates a reference cycle? …
#closure #retain-cycle
Memory and ARCMultiple choiceBasics
Which of the following (with no extra measures) create a reference cycle or a permanent…
#closure #retain-cycle
Memory and ARCShort answerAdvanced
This code, which loads an image asynchronously in a UITableView cell, crashes now and…
#closure #lifetime