Push new View Controller from destination View Controller (swift)

Question

I'm trying to get a destination View Controller to push a new View Controller, but I can't seem to get it, programmatically or via storyboard segues.

Here's what I'm trying to do:

I have 3 View Controllers (let's call them A, B, and C). All three were created (designed?) in the storyboard. I start on view controller A, and when the user presses a button, I want to present view controller B modally, and then when the user selects a cell in view controller B, I want view controller B to be dismissed (modally), and I want view controller A to push a a new view controller (view controller C).

The way I've tried to implement this thus far is when the user presses the button in view controller A, I programmatically modally push view controller B, and then when the user selects a cell in view controller B, I segue back to view controller A, and try to push view controller C from view controller B's prepareForSegue function like this:

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if let viewA = segue.destinationViewController as? ViewControllerA {
        let cell = sender as! ViewControllerBTableViewCell

        var viewC = storyboard?.instantiateViewControllerWithIdentifier("viewControllerC") as! ViewControllerC
        viewC.IDToDisplay = cell.userID
        viewA.navigationController?.pushViewController(viewC, animated: true)
        self.dismissViewControllerAnimated(true, completion: nil)
    }
}

However, when I run this... view controller C is never pushed!

The reason I need to push view controller C from view controller A is that I need the user to be able to navigate back to view controller A from view controller C using the "back" button... not back to view controller B from view controller C.

Essentially the flow I am trying create is view A -> view B modally -> view C ---> back to view A as if view B disappeared (because it should). Please note, however, that view B does need to be able to set the IDToDisplay value of view C before view A pushes to view C.

Is there a clean (standard) way to implement this? Or am I going to have to get janky?

Answer 1

You can solve this problem in two ways

first option: you can create one clousure var in your B controller and execute it before you dissmiss the B controller

for example: In BController

class BTableViewController: UITableViewController {
     var pushClosure:(()->())?


    func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

      pushClosure?()
      self.navigationController?.dismissViewControllerAnimated(true, completion: nil)      
    }

}

And in A controller in the prepareForSegue do something like that

   override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "SegueID" {

        let nextView:BController = segue.destinationViewController as! BController
         nextView.pushClosure = {
            self.performSegueWithIdentifier("SegueID To C Controller", sender:nil)   
        }
     }
   }

The second Option is to implement your own delegate in the BController

protocol ClassNameDelegate{

 func pushToC()

}

class ClassName: NSObject {

  var delegate:ClassNameDelegate?



    func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

      self.delegate.pushToC()
      self.navigationController?.dismissViewControllerAnimated(true, completion: nil)      
    }
 }

And in A controller

 class AViewController:ClassNameDelegate{ 

  func pushToC(){
     self.performSegueWithIdentifier("SegueID To C Controller", sender:nil) 
  }

  override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
       if segue.identifier == "SegueID" {
           let bController:BController = segue.destinationController as! BController
           bController.setDelegate = self
        }
   }
}

I hope it helps you.