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($"[To]View-Model is null.");
}
else
{
await OnNavigatedToAsync(parameters, new_vm);
OnNavigatingTo(parameters, new_vm);
OnNavigatedTo(parameters, new_vm);
}
// refresh-bindings
BindingUtilities.UpdateBindings(new_page);
// finally
return(this.Successful());
}
private async Task <INavigationResult> OrchestrateAsync(
INavigationParameters parameters,
Prism.Navigation.NavigationMode mode,
Func <Task <bool> > navigate)
{
// setup default parameters
CurrentParameters = parameters;
parameters = UpdateInternalParameters(parameters, mode);
// pre-events
var old_vm = (_frame.Content as Page)?.DataContext;
if (old_vm is null)
{
_logger.Log($"No view-model is set for source page; this is okay; skipping all the [from] overrides including CanNavigate/Async.", Category.Info, Priority.None);
}
else if (!await CanNavigateAsync(parameters, old_vm))
{
return(this.NavigationFailure($"[From]{old_vm}.CanNavigateAsync returned false; this is okay; FrameFacade orchestration will stop here."));
}
else if (!CanNavigate(parameters, old_vm))
{
return(this.NavigationFailure($"[From]{old_vm}.CanNavigate returned false; this is okay; FrameFacade orchestration will stop here."));
}
// navigate
var success = await NavigateFrameAsync(navigate);
_logger.Log($"{nameof(FrameFacade)}.{nameof(OrchestrateAsync)}.NavigateFrameAsync() returned {success}.", Category.Info, Priority.None);
if (!success)
{
return(this.NavigationFailure("NavigateFrameAsync() returned false; this is very unusual, but possibly okay; FrameFacade orchestration will stop here."));
}
if (!(_frame.Content is Page new_page))
{
var message = "There is no new page in FrameFacade after NavigateFrameAsync; this is a critical failure. Check the page constructor, maybe?";
_logger.Log(message, Category.Exception, Priority.High);
throw new Exception(message);
}
// post-events
if (old_vm != null)
{
OnNavigatedFrom(parameters, old_vm);
}
var new_vm = new_page?.DataContext;
if (new_vm is null)
{
if (Mvvm.ViewModelLocator.GetAutowireViewModel(new_page) is null)
{
// developer didn't set autowire, and did't set datacontext manually
_logger.Log("No view-model is set for target page, we will attempt to find view-model declared using RegisterForNavigation<P, VM>().", Category.Info, Priority.None);
// set the autowire & see if we can find it for them
Mvvm.ViewModelLocator.SetAutowireViewModel(new_page, true);
// TODO: I wonder if I need to delay for a second?
new_vm = new_page.DataContext;
if (new_vm != null)
{
_logger.Log($"View-Model: {new_vm} found for target View: {new_page}.", Category.Info, Priority.None);
}
}
}
if (new_vm is null)
{
_logger.Log($"View-Model for source page not found; this is okay, skipping all the [to] overides.", Category.Info, Priority.None);
}
else
{
OnNavigatingTo(parameters, new_vm);
await OnNavigatedToAsync(parameters, new_vm);
OnNavigatedTo(parameters, new_vm);
}
// refresh-bindings
BindingUtilities.UpdateBindings(new_page);
// finally
return(this.NavigationSuccess());
}
private async Task <INavigationResult> OrchestrateAsync(
INavigationParameters parameters,
Prism.Navigation.NavigationMode mode,
Func <Task <bool> > navigate)
{
// setup default parameters
parameters = CreateDefaultParameters(parameters, mode);
// pre-events
var old_vm = (_frame.Content as Page)?.DataContext;
if (old_vm == null)
{
Debug.WriteLine($"[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());
}
