Why is a delegated function not being called in swift?

Question

iOS

Good afternoon! Delegation question. Why is the delegate not executed in MainTableViewController? gives no errors.
You can’t put segue here, I’ve been suffering for the second day.

Answer 1

First, this is strange:
var delegate: sideBarDelegate!
...
self.delegate?.sidebarParse
Second, the problem is that you don't store the resulting sideBarTVC in MainTableTVC. On exit from the function, it is removed from memory.
Can you do it like this

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if let identifier = segue.identifier {
            if identifier == "SideBarTVC" {
                let vc = segue.destinationViewController
                vc.delegate = self
            }
        }
}

And do not forget to make the appropriate settings in the storyboard