coordination.cs

interface IPersonRouter
{
	void EditPersonAddress(Address address);
}

public class PersonRouter : IPersonRouter
{
	private QodenController _root;

	PersonRouter(QodenController root) { _root = root; }

	public void EditPersonAddress(Address address)
	{
		var addressEditor = new AddressController();
		addressEditor.Address = address;
		_root.Push(addressEditor);
	}
}

public class PersonController : QodenController
{
	PersonViewModel model;

	protected override void ViewDidLoad()
	{
		model = this.GetViewModelStore().GetViewModel<PersonViewModel>();
		model.Router = new PersonRouter(this);
		//...
	}
}

public class PersonViewModel : DataContext 
{
	public PersonViewModel() 
	{
		EditCommand = new AsyncCommand(EditPersonAddress);
	}

	public IPersonRouter Router { get; set; }

	private async Task EditPersonAddress(object arg,  CancellationToken token)
	{
		var newAddress = await _router.EditPersonAddress(this.Address);
		if (newAddress != null)
		{
			this.Address = newAddress;
			UpdatePersonAddress();
		}
	}
}

public class AddressController : QodenController
{
	AddressViewModel model;

	protected override void ViewDidLoad()
	{
		model = this.GetViewModelStore().GetViewModel<AddressViewModel>();
		//...
	}

	public PersonAddress Address 
	{
		get => model.Address;
		set => model.Address = value;
	}
}