MvvmCross IMvxNavigationFacade, MvxViewModelRequest causes Init() to be called rather than Prepare() - mvvmcross

Question

I've implemented an IMvxNavigationFacade for deep linking in my MvvmCross 5.6.x sample app. I've added logic in BuildViewModelRequest() to construct a MvxViewModelRequest with parameters passed in as MvxBundle.
if (url.StartsWith("http://www.rseg.net/rewards/"))
{
var parametersBundle = new MvxBundle();
var id = url.Substring(url.LastIndexOf('/') + 1);
parametersBundle.Data.Add("id", id);
return Task.FromResult(
new MvxViewModelRequest(typeof(RewardDetailViewModel),
parametersBundle, null));
}
However, this approach causes the old style Init() method to be called in the target ViewModel rather than the new typesafe Prepare() method.
public class RewardDetailViewModel :
MvxViewModel<RewardDetailViewModel.Parameteres>
{
...
public new void Init(string id)
{
if (!string.IsNullOrWhiteSpace(id))
{
if (int.TryParse(id, out _rewardId))
RaiseAllPropertiesChanged();
}
}
public override void Prepare(Parameteres parameter)
{
if (parameter != null)
{
_rewardId = parameter.RewardId;
RaiseAllPropertiesChanged();
}
}
}
Is there a way to construct a MvxViewModelRequest so that you pass in an instance of the parameter class for the target ViewModel causing the Prepare() method to be called?
The entire solution can be viewed on GitHub https://github.com/rsegtx/So.MvvmNav2
Thanks in advance!

Answer 1

After doing some research I found at lease one way to accomplish this.
Create a ViewModelInstanceRequest rather than a ViewModelRequest so that you can call ViewModelLoader.LoadViewModel passing in a parameters object; the ViewModelRequest only allows parameters to be passed using a MvxBundle. Make the following change to BuildViewModelRequest() on the NavigationFacade:
var request = new
MvxViewModelInstanceRequest(typeof(RewardDetailViewModel));
var parameters = new RewardDetailViewModel.Parameteres();
.... parse parameters and fill in parameters object
request.ViewModelInstance = ViewModelLoader.LoadViewModel(
request, parameters, null);
return Task.FromResult((MvxViewModelRequest)request);
Create your own IMvxNavigationService and add logic to inspect the object returned from the NavigationFacde and if it is a ViewModelInstanceRequest then use it as is rather than one previously creating.
var facadeRequest = await facade.BuildViewModelRequest(path,
paramDict).ConfigureAwait(false);
...
if (facadeRequest is MvxViewModelInstanceRequest)
request = facadeRequest as MvxViewModelInstanceRequest;
else
{
facadeRequest.ViewModelType = facadeRequest.ViewModelType;
if (facadeRequest.ParameterValues != null)
{
request.ParameterValues = facadeRequest.ParameterValues;
}
request.ViewModelInstance = ViewModelLoader.LoadViewModel(
request, null);
}
I've updated the original example on GitHub https://github.com/rsegtx/So.MvvmNav2.