/// <summary>
/// Converts a value returned from a LearningStore query to a
/// <c>SequencingLogEntryItemIdentifier</c>, or <c>null</c> if the value is <c>DBNull</c>.
/// </summary>
///
/// <param name="value">A value from a <c>DataRow</c> within a <c>DataTable</c>
/// returned from a LearningStore query.</param>
///
/// <param name="result">Where to store the result.</param>
///
public static void Cast(object value, out SequencingLogEntryItemIdentifier result)
{
LearningStoreItemIdentifier id;
Cast(value, out id);
result = (id == null) ? null : new SequencingLogEntryItemIdentifier(id);
}
/// <summary>
/// Converts a value returned from a LearningStore query to a
/// <c>SequencingLogEntryItemIdentifier</c>. Throws an exception if the value is
/// <c>DBNull</c>.
/// </summary>
///
/// <param name="value">A value from a <c>DataRow</c> within a <c>DataTable</c>
/// returned from a LearningStore query.</param>
///
/// <param name="result">Where to store the result.</param>
///
public static void CastNonNull(object value, out SequencingLogEntryItemIdentifier result)
{
LearningStoreItemIdentifier id;
CastNonNull(value, out id);
result = new SequencingLogEntryItemIdentifier(id);
}
protected void Page_Load(object sender, EventArgs e)
{
// set <attemptId> to the ID of this attempt
AttemptItemIdentifier attemptId = new AttemptItemIdentifier(
Convert.ToInt64(Request.QueryString["AttemptId"], CultureInfo.InvariantCulture));
// set <previousEntryId> to the ID of the sequencing log entry that we most recently
// displayed; newer entries than that will be highlighted
long previousEntryId;
string value = Request.QueryString["PreviousEntryId"];
if (value == null)
{
previousEntryId = long.MaxValue;
}
else
{
previousEntryId = Convert.ToInt64(value, CultureInfo.InvariantCulture);
}
try
{
// create a job to execute two queries
LearningStoreJob job = LStore.CreateJob();
// first query: get the package name and organization title of this attempt
LearningStoreQuery query = LStore.CreateQuery(Schema.MyAttemptsAndPackages.ViewName);
query.AddColumn(Schema.MyAttemptsAndPackages.PackageFileName);
query.AddColumn(Schema.MyAttemptsAndPackages.OrganizationTitle);
query.AddCondition(Schema.MyAttemptsAndPackages.AttemptId,
LearningStoreConditionOperator.Equal, attemptId);
job.PerformQuery(query);
// second query: get the contents of the sequencing log for this attempt
query = LStore.CreateQuery(Schema.SequencingLog.ViewName);
query.AddColumn(Schema.SequencingLog.Id);
query.AddColumn(Schema.SequencingLog.Timestamp);
query.AddColumn(Schema.SequencingLog.EventType);
query.AddColumn(Schema.SequencingLog.NavigationCommand);
query.AddColumn(Schema.SequencingLog.Message);
query.SetParameter(Schema.SequencingLog.AttemptId, attemptId);
query.AddSort(Schema.SequencingLog.Id,
LearningStoreSortDirection.Descending);
job.PerformQuery(query);
// execute the job
ReadOnlyCollection <object> results = job.Execute();
DataTable attemptInfoDataTable = (DataTable)results[0];
DataTable sequencingLogDataTable = (DataTable)results[1];
// extract information from the first query into local variables
DataRow attemptInfo = attemptInfoDataTable.Rows[0];
string packageFileName;
LStoreHelper.CastNonNull(attemptInfo[Schema.MyAttemptsAndPackages.PackageFileName],
out packageFileName);
string organizationTitle;
LStoreHelper.CastNonNull(attemptInfo[Schema.MyAttemptsAndPackages.OrganizationTitle],
out organizationTitle);
// set <trainingName> to the name to use for this attempt
string trainingName;
if (organizationTitle.Length == 0)
{
trainingName = packageFileName;
}
else
{
trainingName = String.Format("{0} - {1}", packageFileName, organizationTitle);
}
// copy <trainingName> to the UI
TrainingName.Text = Server.HtmlEncode(trainingName);
// set <maxLogEntryId> to the highest-numbered log entry ID -- which is the first one,
// since they're sorted by descending entry ID
SequencingLogEntryItemIdentifier maxLogEntryId;
if (sequencingLogDataTable.Rows.Count > 0)
{
DataRow dataRow = sequencingLogDataTable.Rows[0];
LStoreHelper.CastNonNull(dataRow[Schema.SequencingLog.Id],
out maxLogEntryId);
}
else
{
maxLogEntryId = new SequencingLogEntryItemIdentifier(-1);
}
// loop once for each item in the sequencing log
foreach (DataRow dataRow in sequencingLogDataTable.Rows)
{
// extract information from <dataRow> into local variables
SequencingLogEntryItemIdentifier logEntryId;
LStoreHelper.CastNonNull(dataRow[Schema.SequencingLog.Id],
out logEntryId);
DateTime?time;
LStoreHelper.Cast(dataRow[Schema.SequencingLog.Timestamp],
out time);
SequencingEventType?eventType;
LStoreHelper.Cast(dataRow[Schema.SequencingLog.EventType],
out eventType);
NavigationCommand?navigationCommand;
LStoreHelper.Cast(dataRow[Schema.SequencingLog.NavigationCommand],
out navigationCommand);
string message;
LStoreHelper.CastNonNull(dataRow[Schema.SequencingLog.Message],
out message);
// begin the HTML table row
TableRow htmlRow = new TableRow();
// highlight this row if it's new since the last refresh
if (logEntryId.GetKey() > previousEntryId)
{
htmlRow.CssClass = "Highlight";
}
// add the "ID" HTML cell
TableCell htmlCell = new TableCell();
htmlCell.CssClass = "Id_";
htmlCell.Wrap = false;
htmlCell.Text = NoBr(Server.HtmlEncode(logEntryId.GetKey().ToString()));
htmlRow.Cells.Add(htmlCell);
// add the "Time" HTML cell
htmlCell = new TableCell();
htmlCell.CssClass = "Time_";
htmlCell.Wrap = false;
htmlCell.Text = NoBr(Server.HtmlEncode(String.Format("{0:d} {0:t}", time)));
htmlRow.Cells.Add(htmlCell);
// add the "EventType" HTML cell
htmlCell = new TableCell();
htmlCell.CssClass = "EventType_";
htmlCell.Wrap = false;
htmlCell.Text = NoBr(Server.HtmlEncode(eventType.ToString()));
htmlRow.Cells.Add(htmlCell);
// add the "NavigationCommand" HTML cell
htmlCell = new TableCell();
htmlCell.CssClass = "NavigationCommand_";
htmlCell.Wrap = false;
htmlCell.Text = NoBr(Server.HtmlEncode(navigationCommand.ToString()));
htmlRow.Cells.Add(htmlCell);
// add the "Message" HTML cell
htmlCell = new TableCell();
htmlCell.CssClass = "Message_";
htmlCell.Wrap = false;
htmlCell.Text = Server.HtmlEncode(message);
htmlRow.Cells.Add(htmlCell);
// end the table HTML row; add it to the HTML table
LogGrid.Rows.Add(htmlRow);
}
// update <RefreshLink>
RefreshLink.NavigateUrl = String.Format("?AttemptId={0}&PreviousEntryId={1}",
attemptId.GetKey(), maxLogEntryId.GetKey());
}
catch (Exception ex)
{
// an unexpected error occurred -- display a generic message that doesn't include the
// exception message (since that message may include sensitive information), and write
// the exception message to the event log
LogTitle.Visible = false;
LogContents.Visible = false;
ErrorMessage.Visible = true;
ErrorMessage.Controls.Add(new System.Web.UI.LiteralControl(
Server.HtmlEncode("A serious error occurred. Please contact your system administrator. More information has been written to the server event log.")));
LogEvent(System.Diagnostics.EventLogEntryType.Error,
"An exception occurred while accessing the sequencing log for attempt #{0}:\n\n{1}\n\n",
attemptId.GetKey(), ex.ToString());
}
}