example.swift

import UIKit

protocol WorkProtocol: class {
    func work()
}

class ViewModel {
    weak var delegate: WorkProtocol?
}

struct Bar {
    let name: String = "test"
}

struct Foo {
    let bar: Bar
}

class ViewController: UIViewController {

    @Injected var viewModel: ViewModel
    @Injected var foo: Foo
    
    override func viewDidLoad() {
        super.viewDidLoad()

        print(foo.bar.name)

        viewModel.delegate = self

        // Call implementation
        viewModel.delegate?.work()
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        present(ViewController2(), animated: true, completion: nil)
    }
}

extension ViewController: WorkProtocol {

    func work() {
        print("Im working!")
    }
}

class ViewController2: UIViewController {

    @Injected var viewModel: ViewModel

    override func viewDidLoad() {
        super.viewDidLoad()

        viewModel.delegate?.work()
    }
}