private static void OnViewModelRestored(IViewModelProvider sender, ViewModelRestoredEventArgs args)
{
var mainViewModel = args.ViewModel as MainViewModel;
if (mainViewModel != null)
{
var context = args.State.GetData(SelectedItemState);
if (context != null)
{
mainViewModel.SelectedItem = sender.RestoreViewModel(context, DataContext.Empty, false);
}
}
}
public IViewModel RestoreViewModel(IDataContext viewModelState, IDataContext dataContext, bool throwOnError)
{
try
{
dataContext = dataContext.ToNonReadOnly();
if (viewModelState == null)
{
viewModelState = DataContext.Empty;
}
else
{
dataContext.Merge(viewModelState);
}
IViewModel viewModel;
if (!dataContext.GetData(InitializationConstants.IgnoreViewModelCache))
{
Guid id;
if (viewModelState.TryGetData(IdViewModelConstant, out id))
{
viewModel = GetOrAddRestoredViewModel(id).GetViewModel();
if (viewModel != null)
{
return(viewModel);
}
}
}
RestoredViewModel restoredParentViewModel = null;
IViewModel parentViewModel = null;
Guid idParent;
if (viewModelState.TryGetData(IdParentViewModelConstant, out idParent))
{
restoredParentViewModel = GetOrAddRestoredViewModel(idParent);
parentViewModel = restoredParentViewModel.GetViewModel();
if (parentViewModel != null)
{
dataContext.AddOrUpdate(InitializationConstants.ParentViewModel, parentViewModel);
}
}
var restoring = Restoring;
if (restoring != null)
{
var args = new ViewModelRestoringEventArgs {
Context = dataContext, ViewModelState = viewModelState
};
restoring(this, args);
dataContext = args.Context ?? DataContext.Empty;
}
viewModel = RestoreViewModelInternal(viewModelState, dataContext);
if (viewModel != null)
{
if (restoredParentViewModel != null && parentViewModel == null)
{
restoredParentViewModel.AddChildViewModel(viewModel);
}
OnViewModelRestored(viewModel, viewModelState, dataContext);
var restored = Restored;
if (restored != null)
{
var args = new ViewModelRestoredEventArgs(viewModel)
{
Context = dataContext,
ViewModelState = viewModelState
};
restored(this, args);
}
Tracer.TraceViewModel(AuditAction.Restored, viewModel);
if (ReferenceEquals(viewModelState, DataContext.Empty))
{
Tracer.Warn("The view model '{0}' was restored without state.", viewModel);
}
return(viewModel);
}
if (throwOnError)
{
throw ExceptionManager.ViewModelCannotBeRestored();
}
}
catch (Exception e)
{
if (throwOnError)
{
throw;
}
Tracer.Warn(e.Flatten(true));
}
return(null);
}
public void ProviderShouldRestorePreserveViewModelState()
{
bool restoringCalled = false;
bool restoredCalled = false;
bool preservingCalled = false;
bool preservedCalled = false;
var preserveCtx = new DataContext();
var restoreCtx = new DataContext();
DataConstant <string> key = "key";
const string value = "value";
var loadViewModel = new ViewModel();
IocContainer.GetFunc = (type, s, arg3) =>
{
typeof(ViewModel).ShouldEqual(type);
return(loadViewModel);
};
var viewModel = new ViewModel();
viewModel.Settings.State.Add(key, value);
ViewModelProvider provider = GetViewModelProvider(IocContainer);
provider.Preserving += (sender, args) =>
{
sender.ShouldEqual(provider);
args.Context.ShouldEqual(preserveCtx);
args.ViewModel.ShouldEqual(viewModel);
preservingCalled = true;
};
ViewModelPreservedEventArgs preservedEventArgs = null;
provider.Preserved += (sender, args) =>
{
sender.ShouldEqual(provider);
args.Context.ShouldEqual(preserveCtx);
args.ViewModel.ShouldEqual(viewModel);
preservedEventArgs = args;
preservedCalled = true;
};
var state = provider.PreserveViewModel(viewModel, preserveCtx);
state.ShouldEqual(preservedEventArgs.State);
provider.Restoring += (sender, args) =>
{
sender.ShouldEqual(provider);
args.State.ShouldEqual(state);
restoringCalled = true;
};
ViewModelRestoredEventArgs restoredEventArgs = null;
provider.Restored += (sender, args) =>
{
sender.ShouldEqual(provider);
args.State.ShouldEqual(state);
restoredEventArgs = args;
restoredCalled = true;
};
var restoreViewModel = provider.RestoreViewModel(state, restoreCtx, true);
restoreViewModel.ShouldEqual(restoredEventArgs.ViewModel);
restoreViewModel.IocContainer.ShouldEqual(IocContainer);
restoreViewModel.ShouldEqual(loadViewModel);
restoreViewModel.Settings.State.GetData(key).ShouldEqual(value);
restoringCalled.ShouldBeTrue();
restoredCalled.ShouldBeTrue();
preservingCalled.ShouldBeTrue();
preservedCalled.ShouldBeTrue();
}