Programmatic embed segue

Question

I'm using a Page View Controller to implement an image carousel in my app. I have a container view in my parent view controller which has an embed segue to the Page View Controller. The problem I'm having is when I need to go off and fetch these images asynchronously and the segue happens before viewDidLoad gets the images.

My prepare for segue:

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
  if segue.identifier == "startCarousel" {
    let carouselPageViewController = segue.destination as! CarouselPageViewController
    carouselPageViewController.images = carouselImages
  }
}

in viewDidLoad:

GalleryManager.sharedInstance.getData = {
  (data) in
  // Assign images to instance property here ...      
}

My thinking is that once I get the images that I programmatically start the segue myself. Or if I should be doing this a different way any advice would be much appreciated.

Answer 1

You can do something like, return false in shouldPerformSegue and initiate segue when data is loaded i.e.

override func shouldPerformSegue(withIdentifier identifier: String, sender: Any?) -> Bool {
    if identifier  == "startCarousel" {
        return (detail != nil)
    }

    return  true
}

Then in viewDidLoad

GalleryManager.sharedInstance.getData = { [weak self] 
  (data) in
     self?.performSegue(withIdentifier: "startCarousel", sender: nil)
}