General Actions:
Last modified on August 15, 2012 17:21
A typical Enterprise Application requires a user to login first, before they are allowed to do anything.
Cocktail provides an authentication service that implements the required functionality for most types of applications. If desired, the authentication service can be sub-classed and extended. The purpose of the authentication service is to provide a central service to handle the login, logout and current user information.
The authentication service works in conjunction with a DevForce LoginManager.
See also:
- The Login Process
- Use ASP.NET Security
Enable the Authentication Service
The authentication service consist of two parts. The IAuthenticationService interface and the default AuthenticationService implementation. To enable the service, it simply needs to be made available to the application. This is typically accomplished in the application’s bootstrapping logic.
| C# | public class AppBootstrapper : FrameworkBootstrapper<ShellViewModel> { protected override void PrepareCompositionContainer(CompositionBatch batch) { base.PrepareCompositionContainer(batch); batch.AddExportedValue<IAuthenticationService>(new AuthenticationService()); } } |
The AuthenticationService can be configured with specific ConnectionOptions in order to control where it connects. If no ConnectionOptions are specified, ConnectionOptions.Default will be used.
The following snippet shows how to configure the AuthenticationService to connect to the Fake Backing Store.
| C# | public class AppBootstrapper : FrameworkBootstrapper<ShellViewModel> { protected override void PrepareCompositionContainer(CompositionBatch batch) { base.PrepareCompositionContainer(batch); batch.AddExportedValue<IAuthenticationService>(new AuthenticationService() .Configure(auth => auth.WithConnectionOptions(ConnectionOptions.Fake.Name))); } } |
Using the Authentication Service
Once the authentication service is enabled it can be used by simply injecting it where it is needed:
| C# | [Export] public class LoginViewModel : Screen { private readonly IAuthenticationService _authenticationService; [ImportingConstructor] public LoginViewModel(IAuthenticationService authenticationService, [Import(RequiredCreationPolicy = CreationPolicy.NonShared)] IBusyWatcher busy) { Busy = busy; _authenticationService = authenticationService; } public IBusyWatcher Busy { get; private set; } public string Username { get { return _username; } set { _username = value; NotifyOfPropertyChange(() => Username); } } public string Password { get { return _password; } set { _password = value; NotifyOfPropertyChange(() => Password); } } public string FailureMessage { get { return _failureMessage; } set { _failureMessage = value; NotifyOfPropertyChange(() => FailureMessage); } } public IEnumerable<IResult> Login() { using (Busy.GetTicket()) { FailureMessage = ""; var hash = CryptoHelper.GenerateKey(Password); var password = Encoding.UTF8.GetString(hash, 0, hash.Length); var credential = new LoginCredential(Username, password, null); // Clear username and password fields Username = null; Password = null; yield return _authenticationService.LoginAsync(credential, onFail: e => FailureMessage = e.Message); if (_authenticationService.IsLoggedIn) { TryClose(); } } } } |