private INavigationParameters CreateDefaultParameters(INavigationParameters parameters, Prism.Navigation.NavigationMode mode)
{
parameters = parameters ?? new NavigationParameters();
parameters.SetNavigationMode(mode);
parameters.SetNavigationService(_navigationService);
parameters.SetSyncronizationContext(_syncContext);
return(parameters);
}
private async Task <INavigationResult> OrchestrateAsync(
INavigationParameters parameters,
Prism.Navigation.NavigationMode mode,
Func <Task <bool> > navigate)
{
// setup default parameters
parameters = CreateDefaultParameters(parameters, mode);
// pre-events
var old_vm = (_frame.Content as Page)?.DataContext;
if (old_vm == null)
{
Debug.WriteLine($"[From]View-Model is null.");
}
else if (!await CanNavigateAsync(parameters, old_vm))
{
return(this.Failure($"[From]{old_vm}.CanNavigateAsync returned false."));
}
else if (!CanNavigate(parameters, old_vm))
{
return(this.Failure($"[From]{old_vm}.CanNavigate returned false."));
}
// navigate
var success = await NavigateFrameAsync(navigate);
Debug.WriteLine($"{nameof(FrameFacade)}.{nameof(OrchestrateAsync)}.NavigateFrameAsync() returned {success}.");
if (!success)
{
return(this.Failure("NavigateFrameAsync() returned false."));
}
var new_page = _frame.Content as Page;
if (new_page == null)
{
throw new Exception("There is no new page in Frame after Navigate.");
}
// post-events
if (old_vm != null)
{
OnNavigatedFrom(parameters, old_vm);
}
var new_vm = new_page?.DataContext;
if (new_vm == null)
{
if (Mvvm.ViewModelLocator.GetAutowireViewModel(new_page) == null)
{
// developer didn't set autowire, and did't set datacontext manually
// set the autowire & see if we can find it for them
Mvvm.ViewModelLocator.SetAutowireViewModel(new_page, true);
// TODO: I wonder if I need to delay for a second?
new_vm = new_page.DataContext;
}
}
if (new_vm == null)
{
Debug.WriteLine($"[To]View-Model is null.");
}
else
{
await OnNavigatedToAsync(parameters, new_vm);
OnNavigatingTo(parameters, new_vm);
OnNavigatedTo(parameters, new_vm);
}
// refresh-bindings
BindingUtilities.UpdateBindings(new_page);
// finally
return(this.Successful());
}
private INavigationParameters CreateDefaultParameters(INavigationParameters parameters, Prism.Navigation.NavigationMode mode)
{
parameters = parameters ?? new NavigationParameters();
parameters.SetNavigationMode(mode);
parameters.SetNavigationService(_navigationService);
parameters.SetDispatcher(_dispatcher);
return(parameters);
}
private async Task <INavigationResult> OrchestrateNavigation(INavigationParameters parameters, Prism.Navigation.NavigationMode mode, Func <bool> navigate)
{
// default parameters
parameters = parameters ?? new NavigationParameters();
parameters.SetNavigationMode(mode);
parameters.SetNavigationService(_navigationService);
// hold prev vm
var old_vm = (_frame.Content as Page)?.DataContext;
// CanNavigateAsync
if (old_vm is IConfirmNavigationAsync old_vm_confirma)
{
if (!await old_vm_confirma.CanNavigateAsync(parameters))
{
return(NavigationResult.Failure($"{old_vm_confirma}.CanNavigateAsync returned false."));
}
}
// CanNavigate
if (old_vm is IConfirmNavigation old_vm_confirms)
{
if (!old_vm_confirms.CanNavigate(parameters))
{
return(NavigationResult.Failure($"{old_vm_confirms}.CanNavigate returned false."));
}
}
// navigate
await NavigateInternalAsync(navigate);
// OnNavigatedFrom
if (old_vm is INavigatedAware old_vm_ed)
{
old_vm_ed.OnNavigatedFrom(parameters);
}
// hold new vm
var new_vm = (_frame.Content as Page)?.DataContext;
// OnNavigatingTo
if (new_vm is INavigatingAware new_vm_ing)
{
new_vm_ing.OnNavigatingTo(parameters);
}
// OnNavigatedTo
if (new_vm is INavigatedAware new_vm_ed)
{
new_vm_ed.OnNavigatedTo(parameters);
}
// finally
return(NavigationResult.Successful());
}
private async Task <INavigationResult> OrchestrateAsync(
INavigationParameters parameters,
Prism.Navigation.NavigationMode mode,
Func <Task <bool> > navigate)
{
// setup default parameters
parameters = CreateDefaultParameters(parameters, mode);
// pre-events
var old_vm = (_frame.Content as Page)?.DataContext;
if (old_vm == null)
{
Debug.WriteLine($"[From]View-Model is null.");
}
else if (!await CanNavigateAsync(parameters, old_vm))
{
return(NavigationResult.Failure($"[From]{old_vm}.CanNavigateAsync returned false."));
}
else if (!CanNavigate(parameters, old_vm))
{
return(NavigationResult.Failure($"[From]{old_vm}.CanNavigate returned false."));
}
// navigate
var success = await NavigateFrameAsync(navigate);
Debug.WriteLine($"{nameof(FrameFacade)}.{nameof(OrchestrateAsync)}.NavigateFrameAsync() returned {success}.");
if (!success)
{
return(NavigationResult.Failure("NavigateFrameAsync() returned false."));
}
var new_page = _frame.Content as Page;
if (new_page == null)
{
throw new Exception("There is no new page in Frame after Navigate.");
}
// post-events
if (old_vm != null)
{
OnNavigatedFrom(parameters, old_vm);
}
var new_vm = new_page?.DataContext;
if (new_vm == null)
{
if (Central.Registry.TryGetRegistration(_frame.CurrentSourcePageType, out var info) && info.ViewModel != null)
{
new_page.DataContext = new_vm = Central.Container.Resolve(info.ViewModel);
}
}
if (new_vm == null)
{
Debug.WriteLine($"[To]View-Model is null.");
}
else
{
await OnNavigatedToAsync(parameters, new_vm);
OnNavigatingTo(parameters, new_vm);
OnNavigatedTo(parameters, new_vm);
}
// refresh-bindings
BindingUtilities.UpdateBindings(new_page);
// finally
return(NavigationResult.Successful());
}
