public virtual ActionResult LoginRedirect()
{
// Get the details of the currently logged in user.
ShibbolethToken token = ShibbolethToken.CreateCurrent();
// Integrity check.
if (token == null)
{
throw new InvalidOperationException("The Shibboleth token is required!");
}
// Create the view-model.
LoginRedirectVM model = new LoginRedirectVM();
// Validate that the current user has her e-mail address specified, because it is required for the ELMS registration.
// If the e-mail address is missing, then display a specific error message.
if (String.IsNullOrEmpty(token.Email))
{
model.FailureReason = ElmsRegistrationFailureReason.MissingEmail;
return(this.View(Views.LoginRedirect, model));
}
// Try to register the user in the ELMS WebStore.
ElmsRegistrationResult result = ElmsHelper.Register(token);
// If the registration failed, display a specific error message.
if (!result.IsSuccess)
{
model.FailureReason = result.StatusCode == HttpStatusCode.BadRequest
? ElmsRegistrationFailureReason.ClientError
: ElmsRegistrationFailureReason.ServiceError;
return(this.View(Views.LoginRedirect, model));
}
// Redirect the user to the ELMS WebStore only if the registration was successful.
// Integrity check: the redirect URL must be specified.
if (result.RedirectUri == null)
{
throw new InvalidOperationException("The redirect URL must be specified!");
}
// If the redirect URL is specified, then redirect the registered user to the ELMS WebStore.
return(this.Redirect(result.RedirectUri.ToString()));
}
public static ElmsRegistrationResult Register(ShibbolethToken token)
{
// Input validation.
if (token == null)
{
Log.WriteError("ElmsHelper.Register: token is null!");
throw new ArgumentNullException("token");
}
if (String.IsNullOrEmpty(token.Email))
{
Log.WriteError("ElmsHelper.Register: token.Email is null!");
throw new ArgumentException("The e-mail address is required for the registration!");
}
// Prepare the constant parameters.
string accountNumber = ConfigHelper.Elms.AccountNumber;
string key = ConfigHelper.Elms.Key;
// Prepare the user-specific parameters.
string userName = HttpUtility.UrlEncode(token.Email);
string email = HttpUtility.UrlEncode(token.Email);
// Prepare the parameter that describe the user's permissions.
List <string> statusList = new List <string>();
if (token.IsStudent)
{
statusList.Add(ElmsHelper.StudentStatus);
}
if (token.IsSupervisor)
{
statusList.Add(ElmsHelper.StaffStatus);
statusList.Add(ElmsHelper.FacultyStatus);
}
string statuses = String.Join(",", statusList);
// Build the request URL.
string serviceUrl = String.Format(CultureInfo.InvariantCulture, "{0}?account={1}&key={2}&username={3}&academic_statuses={4}&email={5}", ElmsHelper.RegistrationUrl, accountNumber, key, userName, statuses, email);
// Integrity check: the built URL must be a valid URI.
Uri serviceUri;
if (!Uri.TryCreate(serviceUrl, UriKind.Absolute, out serviceUri))
{
Log.WriteError("ElmsHelper.Register: Invalid ServiceURL: {0}", serviceUrl);
throw new InvalidOperationException("The service URL is invalid!");
}
// Send the HTTP GET request to the ELMS WebStore.
ElmsRegistrationResult result = new ElmsRegistrationResult();
try
{
// NOTE: This low-level class must be used, becuase the WebClient class does not provide access to the HTTP status code.
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(serviceUri);
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
result.StatusCode = response.StatusCode;
// Check the HTTP status code.
if (response.StatusCode == HttpStatusCode.OK)
{
using (StreamReader reader = new StreamReader(response.GetResponseStream()))
{
// Read the raw content from the HTTP response.
string responseText = reader.ReadToEnd();
// Check that the raw content of the HTTP response is a valid absolute URL.
Uri responseUri;
if (Uri.TryCreate(responseText, UriKind.Absolute, out responseUri))
{
result.IsSuccess = true;
result.RedirectUri = responseUri;
}
}
}
}
}
catch (WebException ex)
{
// Log the error.
Log.WriteError(ex);
Log.WriteError("ElmsHelper.Register: WebException! ServiceURL: {0}", serviceUrl);
HttpWebResponse response = ex.Response as HttpWebResponse;
if (response != null)
{
Log.WriteError("ElmsHelper.Register: WebException! StatusCode: {0}", response.StatusCode);
Log.WriteError("ElmsHelper.Register: WebException! StatusDescription: {0}", response.StatusDescription);
}
// Treat the registration unsuccessful in case of any error.
result.IsSuccess = false;
}
catch (Exception ex)
{
// Log the error.
Log.WriteException(ex);
// Treat the registration unsuccessful in case of any error.
result.IsSuccess = false;
}
return(result);
}
