Closure property bad access in swift (EXC_BAD_ACCESS) - ios

Question

I have the Test class with button_action optional closure:
class Test : CustomViewFromXib {
var button_action : (() -> ())?
#IBAction func button_pressed(sender: AnyObject) {
if let action = button_action {
action()
}
}
}
This is how I use this class:
let test_view = Test(frame: CGRect.nullRect)
self.view.addSubview(test_view)
test_view.button_action = {
() -> () in
print("test")
}
I get EXC_BAD_ACCESS error at line:
test_view.button_action = {
() -> () in
print("test")
}
I don't know why, because I just want to set initial value. Is it possible to do it that way?
UPDATE:
I understood, that no one property or method can't be called from my object. Not only closures, but Strings (for example) too.
UPDATE 2:
This is my little example of code that reproduces the problem. I think I have a problem with initializers...
https://www.dropbox.com/s/1d8fvxm0es9b5n4/TestInit.zip
(XCode 6 Beta 5)

Answer 1

Write code
let test_view = Test(frame: CGRect.nullRect)
self.view.addSubview(test_view)
test_view.button_action = {
() -> () in
print("test")
}
instead of
let test_view = Test(frame: CGRect.nullRect)
self.view.addSubview(test_view)
test_view.button_action = { [unowned self]
() -> () in
print("test")
}
Here is exact detail theoretical answer
Shall we always use [unowned self] inside closure in Swift
https://developer.apple.com/library/prerelease/mac/documentation/Swift/Conceptual/Swift_Programming_Language/AutomaticReferenceCounting.html