Close<Result> has been removed from IMvxNavigationService

🔙 Regression

I’ve been using MvvmCross since version 7, most I worked with was version 8, lately wanted to upgrade to version 9, what was strange for me was I noticed that I can’t close the ViewModel with return of result like before, after I took a look at the source I saw only one (out of the two) versions of Close method remained and its :

Task<bool> Close(IMvxViewModel viewModel, CancellationToken cancellationToken = default);

however, the implementation still exists in MvxNavigationService

public virtual async Task<bool> Close<TResult>(
            IMvxViewModelResult<TResult> viewModel, TResult result, CancellationToken cancellationToken = default)

Old (and correct) behavior

Exists:

public virtual async Task<bool> Close<TResult>(
            IMvxViewModelResult<TResult> viewModel, TResult result, CancellationToken cancellationToken = default)

Current behavior

Not exists:

public virtual async Task<bool> Close<TResult>(
            IMvxViewModelResult<TResult> viewModel, TResult result, CancellationToken cancellationToken = default)

Reproduction steps

bring back the above method so we can’t return the result from the closed ViewModel

Configuration

Version: 9.x

Platform:

• 📱 iOS
• 🤖 Android
• 🏁 WPF
• 🌎 UWP
• 🍎 MacOS
• 📺 tvOS
• 🐒 Xamarin.Forms

[Cheesebaron]

The workaround is to not use it. You have plenty of options to make something work. I.e. the Parameters for you ViewModel, you could have a callback for backwards navigation. Or you could have some kind of global state. Totally up to you how to tackle it.

[entdark]

Message Bus is the right way. Subscribe for your messages when a VM with a result gets created. Unsubscribe when it gets destroyed. From the VM with a result notify about it. In my projects I made special IResultAwaitingViewModel, IResultSettingViewModel and extended IMvxNavigationService to pass those VMs and they do all the subscribing/unsubscribing logic for me.