public async override void OnNavigatedTo(object navigationParameter, Windows.UI.Xaml.Navigation.NavigationMode navigationMode, Dictionary<string, object> viewModelState) {
base.OnNavigatedTo(navigationParameter, navigationMode, viewModelState);
if (viewModelState != null) {
if (navigationMode == NavigationMode.Refresh) {
var stateErrorsCollection = RetrieveEntityStateValue<IDictionary<string, ReadOnlyCollection<string>>>("stateErrorsCollection", viewModelState);
if (stateErrorsCollection != null) {
SelectedState.SetAllErrors(stateErrorsCollection);
}
}
}
// Note: Each time app selects from main page (StateListPage) detail page (StateDetailPage) is recreated.
// Meaning that constructor is run and SelectedState is null.
// If SuspendAndTerminate (e.g. debug mode) SelectedState is saved to SessionState (because of [RestorableState] attribute).
// Therefore, if SelectedState has been saved, use it instead of doing GetStateAsync.
if (SelectedState == null) {
string errorMessage = string.Empty;
int stateId = (int)navigationParameter;
if (stateId == 0) {
SelectedState = new State();
SelectedState.ValidateProperties();
RunAllCanExecute();
}
else {
try {
LoadingData = true;
CrudResult = await _stateRepository.GetStateAsync(stateId);
SelectedState = JsonConvert.DeserializeObject<List<State>>(CrudResult.Content.ToString()).FirstOrDefault<State>();
}
catch (HttpRequestException ex) {
ErrorMessageTitle = ErrorMessagesHelper.HttpRequestExceptionError;
//TODO: Log stack trace to database here
ErrorMessage = string.Format("{0}", ex.Message);
}
finally {
LoadingData = false;
}
if (ErrorMessage != null && ErrorMessage != string.Empty) {
MessageDialog messageDialog = new MessageDialog(ErrorMessage, ErrorMessageTitle);
await messageDialog.ShowAsync();
_navService.GoBack();
}
}
}
RunAllCanExecute();
}
// When New button is pressed
private void OnNewState() {
SelectedState = new State();
SelectedState.ValidateProperties();
RunAllCanExecute();
}