Skeleton for a Silverlight business application based on Ria Services and the Ria Services Class Library

using System;
using System.Windows;
using System.Windows.Controls;
using System.ComponentModel;
using System.Windows.Ria.ApplicationServices;
using System.Windows.Ria.Data;
using System.Windows.Data;
using System.Windows.Ria;
using BASample.Data.Model;
using BASample.Data.DomainService;

namespace BASample.Silverlight
{
	public partial class LoginWindow : ChildWindow
	{
		private AuthenticationService _authService = RiaContext.Current.Authentication;
		private AuthenticationOperation _authOp;

		private AppUser appUser = new AppUser();
		private AppUserContext appUserContext = new AppUserContext();
		private SubmitOperation _regOp;

		public LoginWindow()
		{
			InitializeComponent();
			this.loginButton.IsEnabled = false;

			this.appUserContext.AppUsers.Add(this.appUser);
			this.registerForm.CurrentItem = this.appUser;
		}

		protected override void OnClosing(CancelEventArgs e)
		{

			if (_regOp != null && _regOp.CanCancel)
			{
				_regOp.Cancel();
			}

			if (_authOp != null && _authOp.CanCancel)
			{
				_authOp.Cancel();
			}

			base.OnClosing(e);
		}


		private void CancelButton_Click(object sender, RoutedEventArgs e)
		{
			this.DialogResult = false;
		}

		private void LoginButton_Click(object sender, RoutedEventArgs e)
		{
			SetEditableState(false);
			_authOp = _authService.Login(this.loginUserNameBox.Text, this.loginPasswordBox.Password);
			_authOp.Completed += LoginOperation_Completed;
		}


		private void LoginOperation_Completed(object sender, EventArgs e)
		{
			LoginOperation loginOp = (LoginOperation)sender;

			if (loginOp.LoginSuccess)
			{
				this.DialogResult = true;
				_authOp = null;
			}
			else
			{
				if (loginOp.HasError)
				{
					SetEditableState(true, true);
					new ErrorWindow(loginOp.Error.Message).Show();
				}
				else
				{
					SetEditableState(true, true);
					new ErrorWindow("Login failed. Please verify user name and password and try again.").Show();
				}
			}
		}

		private void RegisterButton_Click(object sender, RoutedEventArgs e)
		{
			SetEditableState(false);

			if (this.registerForm.ValidateItem() && this.registerForm.CommitEdit())
			{
				_regOp = appUserContext.SubmitChanges();
				_regOp.Completed += RegistrationOperation_Completed;
			}
			else
			{
				SetEditableState(true);
			}
		}

		private void RegistrationOperation_Completed(object sender, EventArgs e)
		{
			SubmitOperation asyncResult = (SubmitOperation)sender;

			if (asyncResult.HasError)
			{
				new ErrorWindow(asyncResult.Error.Message).Show();
				SetEditableState(true, true);
			}
			else if (!asyncResult.IsCanceled)
			{
				_authOp = RiaContext.Current.Authentication.Login(this.appUser.Name, this.appUser.Password);
				_authOp.Completed += LoginOperation_Completed;
			}

			_regOp = null;
		}

		private void RegisterNow_Click(object sender, RoutedEventArgs e)
		{
			VisualStateManager.GoToState(this, "GoToNothingTransition", true);
			VisualStateManager.GoToState(this, "GoToRegisterTransition", true);
			ToRegister.Begin();
			this.Title = "Register";
		}

		private void LoginUserNameBox_TextChanged(object sender, TextChangedEventArgs e)
		{
			SetLoginButtonEnabled();
		}

		private void LoginPasswordBox_PasswordChanged(object sender, RoutedEventArgs e)
		{
			SetLoginButtonEnabled();
		}

		private void SetLoginButtonEnabled()
		{
			this.loginButton.IsEnabled = (this.loginUserNameBox.Text.Length != 0) && (this.loginPasswordBox.Password.Length != 0);
		}

		private void SetEditableState(bool enabled)
		{
			SetEditableState(enabled, false);
		}

		private void SetEditableState(bool enabled, bool setRegisterFormEditState)
		{

			activity.IsActive = !enabled;


			if (this.loginPanel.Visibility == Visibility.Collapsed)
			{
				this.registerForm.IsEnabled = enabled;
				this.registerButton.IsEnabled = enabled;
				this.backToLogin.IsEnabled = enabled;
				if (enabled && setRegisterFormEditState)
				{
					this.registerForm.BeginEdit();
				}
			}
			else
			{
				this.loginButton.IsEnabled = enabled;
				this.loginUserNameBox.IsEnabled = enabled;
				this.loginPasswordBox.IsEnabled = enabled;
				this.registerNow.IsEnabled = enabled;
				this.loginUserNameBox.Focus();
			}

		}

		private void BackToLogin_Click(object sender, RoutedEventArgs e)
		{
			VisualStateManager.GoToState(this, "GoToNothingTransition", true);
			VisualStateManager.GoToState(this, "GoToLoginTransition", true);
			ToLogin.Begin();
			this.Title = "Login";
		}

	}
}