Delegation to Presenting VC, From a Popover

Question

I dragged a ViewController onto my storyboard, segued to it with a popover segue, and setup the size and style in the presentingVC's prepareForSegue. My question is, if my popover has several buttons, where should their code be executed?

For example, should I use a delegation pattern where, in the prepareForSegue, I pass the delegation reference as self? Then delegate backward?
Or, should I create a new viewController for the popover, then put the code to be run in there?
I also read this tutorial and someone said...

" And you get hold of the the content controller by using the popoverPresentationController.presentedViewController method in the UIPopoverPresentationController

What would be ideal for me, since the code I want will change some presentingVC variables, would be delegate back to the presenting VC.

Tapani · Answer 1 · 2016-02-07T14:46:35.260

0

Just set the popover button actions in prepareForSegue to point to functions in the presentingVC.

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if let dest = segue.destinationViewController as? MyPopoverViewController {
        let myButton = dest.view.viewWithTag(MY_BUTTON_TAG) as! UIButton
        myButton.addTarget(self, action: "onMyButton", forControlEvents: .TouchUpInside)
    }
}

func onMyButton() {
    ...
}

Or even better with closures using an UIButton extension like this:

https://www.mikeash.com/pyblog/friday-qa-2015-12-25-swifty-targetaction.html

edited Feb 07 '16 at 14:46

answered Feb 07 '16 at 13:34

Tapani

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Thanks Tapani. I've never seen any method like this before. Would you mind explaining why this is the way to do it? I like to progress as a developer and not just implement code in my app without understanding it. Why this new way and not delegation? – Dave G Feb 07 '16 at 13:52
1

I don't believe this will work. The outlets in the `destinationViewController` are not setup at `prepareForSegue` time, so `dest.myButton` would be `nil`. – vacawama Feb 07 '16 at 14:24
You can always find the button by tag. That way the outlets don't need to be set and you don't even need a class for the popover view controller. – Tapani Feb 07 '16 at 14:44
I think delegates became outdated when block were introduced to Objective-C and even more with Swift closures. I would create a class for the popoverOverViewController, connect IBActions and call a closure in the action handler. In prepareForSegue I would set the closure, which the action handler calls. viewWithTag approach, however, requires less code. – Tapani Feb 07 '16 at 14:49

score 0 · Accepted Answer · answered Feb 11 '16 at 13:42

Ultimately just went with delegation in the competition block of the dismiss popover call:

class NavigationViewController: UIViewController {

    var presentingVC_Delegate: mainLists_PopoverDelegation!
    var whatToDo = "Placeholder"

    @IBOutlet var shareBtn: UIButton!
    @IBOutlet var clearBtn: UIButton!
    @IBOutlet var settingsBtn: UIButton!

    //***** ----- ***** ------ ***** ----- ***** ----- *****
    //Menu Button Functions
    //***** ----- ***** ------ ***** ----- ***** ----- *****
    @IBAction func shareBtn_Pressed(sender: AnyObject) {
        self.dismissViewControllerAnimated(true, completion: { finished in
            self.presentingVC_Delegate.call_ActivityVC()
        })
    }
    @IBAction func clearBtn_Pressed(sender: AnyObject) {
        self.dismissViewControllerAnimated(true, completion: { finished in
            self.presentingVC_Delegate.deleteList()
        })
    }
    @IBAction func settingsBtn_Pressed(sender: AnyObject) {
        self.dismissViewControllerAnimated(true, completion: { finished in
            self.presentingVC_Delegate.presentSettingsVC()
        })
    }
}

protocol mainLists_PopoverDelegation {
  func call_ActivityVC ()
  func deleteList ()
  func presentSettingsVC ()
}

With those three functions located in the main VC.

Delegation to Presenting VC, From a Popover

2 Answers2