Present a UIViewController from a UIHostingViewController

I'm starting to rebuild my app from Swift to SwiftUI.

I have one UIViewController that is built using UIPresentationController and has custom drag gestures that I would like to use as-is (for now).

I'm trying to figure out if I am able to present this from my SwiftUI View.

Here is how I navigate to the SwiftUI view:

let dataStore = DataStore()
let vc = Host(rootView: SwiftUIView(store: dataStore))
self.navigationController?.pushViewController(vc, animated: true)

The method to present my controller is in my DataStore.

Here is what I am trying:

func displayDetailController(forData data: Data?) {
     let height = // I set a custom height here as I can drag 
     //this view to pop to the middle, to the top, or dismiss
     guard let dat = data else { return }
     let const = DetailViewController.Constructor(data: dat)
     let vc = DetailViewController.loadFromNib(constructor: const, height: height) 
        
     let hostingController = Host(rootView: SwiftUIView(store: self))
     hostingController.navigationController?.present(vc, animated: true)
}

I have a Button that when tapped will call displayDetailController but nothing happens.

The goal being my DetailViewController is presented and I can see my data and use the drag gestures.

Solution

Right now, you're creating a new Host and SwiftUIView and trying to present from them. But, they aren't part of the view hierarchy, so nothing gets presented.

Instead, you probably want to pass a reference to your actual view controller. This code is incomplete, since you didn't include definitions for everything, but it should get you started:

let dataStore = DataStore()
dataStore.navigationController = self.navigationController
let vc = Host(rootView: SwiftUIView(store: dataStore))
self.navigationController?.pushViewController(vc, animated: true)

class DataStore {
  var navigationController : UINavigationController?

  // other code

  func displayDetailController(forData data: Data?) {
     let height = 100
     guard let dat = data else { return }
     let const = DetailViewController.Constructor(data: dat)
     let vc = DetailViewController.loadFromNib(constructor: const, height: height) 
     self.navigationController?.present(vc, animated: true)
  }
}