public async Task<bool> Submit(User user)
{
bool submitted;
if (user.Blocked)
throw new Exception("User blocked.");
var userDb = _users.FirstOrDefault(e => e.Id == user.Id);
if (userDb != null)
{
userDb.Group = user.Group;
submitted = true;
}
else
submitted = false;
return await Task.FromResult(submitted);
}
public UserViewModel(IScreen screen, User user, IUserRepository userRepository)
{
_userRepository = userRepository;
HostScreen = screen;
// Commands
var canSubmit = this.WhenAny(e => e.Code, code => code.Value.IsValid());
Submit = ReactiveCommand.CreateAsyncTask(canSubmit, _ => userRepository.Submit(Model));
Submit.Subscribe(result => MessageBox.Show(result ? "Success" : "Failure"));
// Observe on UI thread
Submit.ThrownExceptions.ObserveOn(RxApp.MainThreadScheduler)
.Select(ex => new UserError("It will fail again, try anyway?", ex.Message))
.SelectMany(UserError.Throw)
.Subscribe(resolution =>
{
if (resolution == RecoveryOptionResult.RetryOperation)
Submit.Execute(null);
});
// Model subscription
this.WhenAnyValue(e => e.Model).Where(e => e != null).Subscribe(model =>
{
Code = model.Code;
Group = model.Group;
});
Model = user;
// Properties subscriptions
this.WhenAnyValue(e => e.Group).Subscribe(group => Model.Group = group);
this.WhenAnyValue(e => e.Code).Subscribe(code => Model.Code = code);
// Subscribe to error handle
UserError.RegisterHandler(async error =>
{
// This shouldn't be a messagebox because is blocking the application, you must provide context and offer a resolution to the user not just showing "error"
await Task.Delay(1);
var message = new StringBuilder();
bool hasRecoveryOptions = error.ErrorCauseOrResolution.IsValid();
if (hasRecoveryOptions)
message.AppendLine(error.ErrorCauseOrResolution);
message.AppendLine(error.ErrorMessage);
var result = MessageBox.Show(message.ToString(), "Alert!",
hasRecoveryOptions ? MessageBoxButton.YesNo : MessageBoxButton.OK);
return hasRecoveryOptions && result == MessageBoxResult.Yes ? RecoveryOptionResult.RetryOperation : RecoveryOptionResult.CancelOperation;
});
}
public async Task<IList<Menu>> GetMenuByUser(User user)
{
if (user == null)
return new List<Menu> {new Menu(MenuOption.Login)};
// TODO real call to DB
List<Menu> result = (user.Group == UserGroup.Admin)
? new List<Menu>
{
new Menu(MenuOption.Login),
new Menu(MenuOption.User),
new Menu(MenuOption.Placeholder)
}
: new List<Menu>
{
new Menu(MenuOption.User),
new Menu(MenuOption.Placeholder)
};
return await Task.FromResult(result);
}
