/// <summary>
/// A relaxed utility function that doesn't impose mandatory requirements for Session values to exist in the Session.
/// Returns a value from Session if it exists. Returns null if value isn't present.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="var"></param>
/// <returns></returns>
private static Nullable <T> GetNullableSessionValue <T>(SessionVars var) where T : struct
{
if (HttpContext.Current.Session[var.Description()] != null)
{
return((T)HttpContext.Current.Session[var.Description()]);
}
else
{
return(null);
}
}
/// <summary>
/// Private helper Generic function to facilitate retrieval of value from Session
/// </summary>
private static T GetNonNullSessionValue <T>(SessionVars variableName)
{
if (DoesSessionVariableExist(variableName))
{
return((T)HttpContext.Current.Session[variableName.Description()]);
}
else
{
string error = "Unable to retrieve session value for : " + variableName.Description();
throw new ShiptalkCommon.ShiptalkException(error, true, new System.Security.SecurityException(error), "Sorry. We lost some session information. Please login again.");
}
}
/// <summary>
/// Verifies Session for the existence of a value for a Session variable.
/// </summary>
/// <param name="var"></param>
/// <returns></returns>
public static bool DoesSessionVariableExist(SessionVars var)
{
if (HttpContext.Current.Session != null)
{
return(!(HttpContext.Current.Session[var.Description()] == null));
}
else
{
return(false);
}
}
/// <summary>
/// Private helper Generic function to facilitate setting value to Session variable.
/// </summary>
private static void SetSessionValue <T>(SessionVars variableName, T value)
{
HttpContext.Current.Session[variableName.Description()] = value;
}